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AI Token Cost CalculatorCalculatorCalculate estimated LLM input and output cost for one request or a batch using editable prices per million tokens and manual or text-estimated usage.→AI Token CounterDeveloperEstimate AI prompt tokens with a transparent English, code, or multilingual heuristic, including a planning range, characters, UTF-8 bytes, words, and detected content profile.→API Key GeneratorGeneratorGenerate secure API keys with configurable length, prefix, quantity, and URL-safe, hexadecimal, Base32, or alphanumeric formats.→Alternating Case ConverterTextConvert ordinary text into alternating uppercase and lowercase letters while preserving spaces, punctuation, numbers, and line breaks.→Article Schema GeneratorSeoGenerate Article JSON-LD with headline, author, publisher, dates, image, and canonical URL.→BCrypt Hash GeneratorGeneratorGenerate a salted 60-character BCrypt password hash, choose cost 4–15, inspect its parts, measure runtime, and verify it immediately.→BCrypt VerifyValidatorVerify a plain-text password against a BCrypt hash safely, understand match results, and troubleshoot invalid hash formats without attempting to decode the hash.→Base64 DecoderEncode DecodeDecode standard Base64 online to UTF-8 text or inspect decoded binary bytes as hexadecimal.→Base64 EncoderEncode DecodeEncode UTF-8 text to standard Base64 online with optional 64- or 76-character line wrapping and canonical padding.→Base64URL DecoderConverterDecode padded or unpadded Base64URL data back to readable UTF-8 text.→Base64URL EncoderConverterEncode UTF-8 text with the URL-safe Base64 alphabet and optional padding.→Basic Auth Header GeneratorGeneratorBasic Auth Header Generator creates an HTTP Authorization header by Base64-encoding a username and password for controlled API and server testing.→Breadcrumb Schema GeneratorSeoGenerate BreadcrumbList JSON-LD from names and canonical URLs.→CNAME LookupNetworkCNAME Lookup checks whether a hostname is an alias, shows its canonical target and TTL, and helps diagnose DNS redirects between hostnames.→CORS Header GeneratorGeneratorGenerate validated CORS response headers for one origin, methods, request headers, exposed response headers, credentials, and preflight caching.→CRC32 GeneratorGeneratorGenerate CRC32 checksums from exact text in hexadecimal and decimal formats for compatibility checks, fixtures, archives, and data-transfer testing.→CSP Policy BuilderGeneratorBuild a Content-Security-Policy header with presets, source directives, Report-Only mode, security warnings, and copy-ready HTTP, nginx, Apache and meta-tag output.→CSS BeautifierDeveloperUse CSS Beautifier to format compressed or inconsistent CSS online with readable indentation, line breaks, declarations, selectors, comments, and nested blocks.→CSS MinifierDeveloperMinify CSS by removing unnecessary spaces and comments for smaller stylesheets, cleaner delivery, and deployment workflows→CSV FormatterTableNormalize CSV rows, delimiters, quoting, whitespace, and column structure into consistent downloadable output.→CSV MergerTableCombine compatible CSV datasets into one file while checking headers, delimiters, and record structure.→CSV SplitterTableSplit a large CSV dataset into smaller files by row count while preserving the header and record structure.→CSV ValidatorValidatorValidate UTF-8 CSV structure, delimiter choice, quoting, header names and consistent column counts before import or conversion.→CSV ViewerTableOpen CSV data in a clear table, inspect rows and columns, and review structured records before using them elsewhere.→CSV to JSONDeveloperConvert UTF-8 CSV, TSV, semicolon or pipe-delimited rows to a formatted JSON array with header controls, delimiter detection and empty-value handling.→Canonical URL CheckerSeoCheck a canonical URL for syntax, protocol, fragments, query parameters, normalization issues, and page alignment.→Case ConverterTextConvert text to camelCase, PascalCase, snake_case and more.→Certificate DecoderEncode DecodeDecode one X.509 PEM certificate and inspect subject, issuer, validity, SAN entries, fingerprints, serial number, signature, and key usage.→Character CounterTextMeasure characters with and without spaces, plus words and lines, for social posts, forms, metadata, and editing→Checksum CalculatorEncode DecodeCalculate CRC32, MD5, SHA-1, SHA-256, SHA-384, or SHA-512 checksums from exact text and compare deterministic outputs across systems.→Collapse SpacesTextCollapse repeated horizontal spaces into one space while preserving line breaks, paragraph structure, and the order of your text.→Comma List to LinesTextConvert comma-separated values into one trimmed item per line, omit empty entries, and prepare a clean vertical list for spreadsheets or imports.→Content-Type ParserDeveloperParse a Content-Type header into its media type, charset, boundary, and other parameters.→Cookie ParserDeveloperParse a Cookie request header into readable cookie names and values.→Cron Expression BuilderGeneratorBuild and validate five-field cron expressions with presets and human-readable explanations.→Cron Expression GeneratorGeneratorGenerate standard five-field cron expressions for hourly, daily, weekday, weekly, monthly, or custom schedules.→Cron Expression ParserDeveloperSplit a standard five-field cron expression into minute, hour, day-of-month, month, and weekday explanations.→DNS LookupNetworkLook up DNS records for a domain, including A, AAAA, MX, TXT, NS, CNAME, SOA, and CAA records.→Data URL DecoderConverterDecode a data URL and inspect its media type, encoding, parameters, and text payload.→Data URL EncoderConverterEncode text as a standards-friendly data URL with a selected media type and encoding mode.→Duplicate Paragraph RemoverTextRemove repeated paragraphs while preserving order.→Email ExtractorTextFind email addresses in authorized pasted text, remove repeated matches, and return a clean copyable list in first-seen order.→Emoji RemoverTextRemove emoji symbols and related joiner characters from text while preserving surrounding words, punctuation, spacing, and line structure.→FAQ Schema GeneratorSeoGenerate FAQPage JSON-LD from visible questions and answers.→Find and ReplaceTextReplace every exact occurrence of a chosen text value while keeping the source available for comparison.→GraphQL FormatterDeveloperGraphQL Formatter turns compressed GraphQL queries, mutations, fragments, and variables into readable structured output for faster review, debugging, and team collaboration.→GraphQL MinifierDeveloperGraphQL Minifier removes unnecessary whitespace and comments from GraphQL queries while preserving operations, fragments, variables, directives, and string values.→HMAC GeneratorGeneratorGenerate keyed HMAC digests from a message and secret using SHA-256, SHA-384, or SHA-512, with clear hexadecimal output for testing integrations.→HTML BeautifierDeveloperFormat compact or inconsistent HTML with readable indentation, line breaks, nested elements, comments, and document structure.→HTML DecoderEncode DecodeDecode HTML entities into readable characters for content cleanup, debugging, migration, and template review→HTML EncoderEncode DecodeEncode reserved HTML characters into entities for safe display in examples, documentation, templates, and web content→HTML MinifierDeveloperMinify HTML by removing unnecessary whitespace and comments for smaller markup, faster transfer, and deployment preparation→HTML Tag RemoverDeveloperRemove HTML tags from markup while keeping readable text for cleanup, migration, extraction, and content preparation→HTTP Authorization Header ParserDeveloperInspect HTTP Authorization headers and identify Bearer, Basic, and other authentication schemes.→HTTP Header BuilderGeneratorBuild validated HTTP request and response header blocks for APIs, security, caching, CORS, and content negotiation.→HTTP Header CheckerNetworkInspect HTTP response headers, caching, content metadata, CORS, and common security headers for a public URL.→HTTP Request BuilderGeneratorBuild a complete HTTP request and matching cURL command from structured fields.→HTTP Status CheckerNetworkCheck the live HTTP status of a public URL, follow redirects, and review the final response and request path.→HTTP Status Code LookupNetworkLook up common HTTP response codes and use detailed guides for 301, 302, 401, 403, 404, 429, 500, 502, and 503 errors.→Hash GeneratorGeneratorUse this free Hash Generator to create MD5, SHA-1, SHA-256, and SHA-512 hashes from text, verify exact input, and copy results online.→Hashtag ExtractorTextExtract unique hashtags from captions, notes, and campaign text in their original first-seen order.→Hreflang GeneratorSeoGenerate a reciprocal hreflang cluster as HTML link tags and a complete same-site XML sitemap, with normalized locales and optional x-default.→IP Address LookupNetworkInspect a public IPv4 or IPv6 address, reverse hostname, address version, canonical form, and forward-confirmed DNS context.→ISO 8601 Date ConverterConverterConvert ISO 8601 timestamps between UTC, Unix time, and readable date formats.→JSON CompareCompareCompare two JSON documents online, validate their syntax, normalize formatting, and highlight added, removed, changed, and unchanged lines.→JSON Diff ViewerCompareCompare two JSON documents online, validate their syntax, normalize formatting, and inspect added, removed, or changed values in a clear diff.→JSON EscapeEncode DecodeEscape quotes, backslashes, line breaks, tabs and Unicode-safe text for use inside JSON string values, API payloads and configuration files.→JSON FlattenConverterFlatten nested JSON objects and arrays into reversible $-rooted path-value pairs while preserving empty objects, empty arrays, scalar types, and array indexes.→JSON FormatterDeveloperFormat, beautify or minify JSON online with 2-space, 4-space or tab indentation, optional recursive key sorting, validation, and copy-ready output.→JSON Lines FormatterDeveloperValidate and normalize JSON Lines or JSONL data as one compact JSON value per line, with strict blank-record detection and an optional final newline.→JSON MergeConverterMerge 2 JSON documents online with recursive object merging, selectable conflict priority and replace, append or unique array strategies.→JSON MinifierDeveloperMinify formatted JSON into a compact single-line representation for APIs, storage, testing, and data transfer.→JSON Path FinderDeveloperFind JSONPath-style locations for matching keys or values inside deeply nested JSON without manually tracing the structure.→JSON Pointer TesterDeveloperResolve an RFC 6901 JSON Pointer against an object or array, including escaped slash and tilde characters, and inspect the selected value.→JSON Schema GeneratorGeneratorGenerate a JSON Schema from sample JSON online. Choose Draft 4, 6, 7, 2019-09 or 2020-12, infer nested types and detect common string formats.→JSON Schema ValidatorValidatorValidate JSON data against a practical JSON Schema subset and receive errors with exact data paths for types, required fields, arrays, strings and numbers.→JSON SorterDeveloperUse this free JSON Sorter to alphabetize object keys recursively while preserving values, nested structures, and array order online.→JSON UnescapeEncode DecodeDecode JSON escape sequences such as escaped quotes, backslashes, newlines, tabs and Unicode sequences into readable text.→JSON UnflattenConverterRebuild nested JSON objects and arrays from a reversible $-rooted flat path map with collision checks, escaped property names, and strict contiguous array indexes.→JSON ValidatorValidatorValidate JSON syntax online and inspect the document root type, nesting depth, node count, object keys, arrays, objects and scalar values.→JSON ViewerDeveloperView JSON online as a readable tree, pretty-printed document, or flattened JSON path list with value types and depth controls.→JSON to C# ClassConverterConvert representative JSON into reviewable C# output with type inference, nested models, arrays, and practical generation settings.→JSON to CSVConverterConvert a non-empty JSON array of objects to CSV with selectable delimiter, header and line-ending options, nested JSON serialization and spreadsheet formula protection.→JSON to Dart ClassConverterConvert representative JSON into reviewable Dart output with type inference, nested models, arrays, and practical generation settings.→JSON to Go StructConverterConvert representative JSON into reviewable Go output with type inference, nested models, arrays, and practical generation settings.→JSON to Java ClassConverterConvert representative JSON into reviewable Java output with type inference, nested models, arrays, and practical generation settings.→JSON to Kotlin Data ClassConverterConvert representative JSON into reviewable Kotlin output with type inference, nested models, arrays, and practical generation settings.→JSON to OpenAI Function SchemaConverterConvert representative JSON arguments into an OpenAI function tool definition for the Responses API or Chat Completions.→JSON to PHP DTOConverterConvert representative JSON into reviewable PHP output with type inference, nested models, arrays, and practical generation settings.→JSON to Pydantic ModelConverterGenerate Pydantic v2 BaseModel classes from JSON with nested models, Python type hints, nullable options, and Field aliases for JSON keys.→JSON to Rust StructConverterConvert representative JSON into reviewable Rust/Serde output with type inference, nested models, arrays, and practical generation settings.→JSON to SQL CREATE TABLEConverterConvert representative JSON into reviewable SQL output with type inference, nested models, arrays, and practical generation settings.→JSON to Swift CodableConverterConvert representative JSON into reviewable Swift output with type inference, nested models, arrays, and practical generation settings.→JSON to TOMLConverterConvert JSON objects into readable TOML configuration.→JSON to TOON ConverterConverterJSON to TOON Converter transforms JSON into compact TOON v4.1 syntax using indentation-based objects, explicit array lengths, and tabular rows for uniform object arrays.→JSON to TypeScriptConverterGenerate a TypeScript interface from representative JSON objects, arrays and primitive values, with a configurable root interface name.→JSON to XML ConverterConverterJSON to XML Converter transforms JSON objects and arrays into structured XML for integration, migration, and testing workflows.→JSON to YAMLConverterConvert valid JSON objects, arrays and scalar values to readable YAML while preserving nesting, strings, numbers, booleans, null and Unicode text.→JSON to Zod SchemaConverterConvert representative JSON into a Zod schema with nested objects, arrays, primitive types, null values, and optional strict object handling.→JWT Claims InspectorSecurityInspect standard JWT claims such as issuer, audience, subject, issued-at, not-before, and expiration.→JWT DecoderEncode DecodeDecode JWT header and payload online, inspect alg/type and time claims, and see expiration status without pretending to verify the signature.→JWT Expiration CheckerSecurityCheck JWT exp, nbf, and iat claims and see whether a token is active, expired, or not active yet.→JWT GeneratorGeneratorCreate signed HS256 JSON Web Tokens.→JavaScript BeautifierDeveloperUse JavaScript Beautifier to format compact JavaScript online with readable indentation, braces, statements, operators, comments, strings, and template literals.→JavaScript MinifierDeveloperUse JavaScript Minifier to remove comments and unnecessary whitespace from JavaScript online while preserving strings, template literals, identifiers, and operators.→Keyword Density CheckerSeoAnalyze keyword frequency, density, top terms, and phrase usage in page copy.→Line CounterTextCount total, non-empty, and blank lines in text, code, lists, logs, and documents with a clear browser workflow→Lines to Comma ListTextJoin non-empty trimmed lines into one comma-separated list while preserving the original item order.→Local Business Schema GeneratorSeoGenerate LocalBusiness JSON-LD with address, contact, opening hours, price range, and coordinates.→Lowercase ConverterTextConvert cased letters to lowercase while preserving punctuation, spaces, and line breaks.→MCP Schema ValidatorValidatorValidate the core structure of one MCP tool definition, including its name, description, inputSchema, required fields, outputSchema, and annotations.→MCP Tool Schema GeneratorGeneratorGenerate a minimal MCP tool definition and Draft 2020-12 inputSchema from a tool name, description, and representative JSON arguments.→MD5 GeneratorGeneratorUse this free MD5 Generator to generate a MD5 hash from exact text, verify whitespace and encoding, and copy a clean hexadecimal digest online.→MX LookupNetworkMX Lookup checks a domain’s mail exchanger records, priorities, TTL values, and receiving mail servers so you can verify email DNS routing.→Markdown PreviewTextRender common Markdown syntax as safe HTML so structure and formatting can be reviewed before publishing.→Markdown to HTMLConverterConvert common Markdown syntax into HTML for previews, documentation, articles, notes, and lightweight publishing workflows.→Mention ExtractorTextExtract unique @mentions from authorized text and preserve the order in which accounts first appear.→Meta Length CheckerSeoCheck SEO title and meta description lengths with practical search snippet guidance.→Meta Tags GeneratorSeoGenerate essential HTML meta tags for search, sharing, indexing, and canonical URLs.→NS LookupNetworkNS Lookup checks the authoritative nameserver records published for a domain so you can verify DNS delegation, hostnames, and TTL values.→Number ExtractorTextExtract signed integers and decimal values from mixed text while preserving their original order.→Open Graph GeneratorSeoGenerate Open Graph meta tags for rich social media previews.→OpenAPI GeneratorGeneratorGenerate an OpenAPI 3.1 document from endpoint settings and JSON request or response samples.→OpenAPI ValidatorValidatorValidate the required structure of OpenAPI 3.0 and 3.1 documents supplied as JSON or YAML.→Organization Schema GeneratorSeoGenerate Organization JSON-LD with identity, logo, contact and social profiles.→PEM FormatterEncode DecodeFormat PEM certificates and keys, validate matching boundary labels, and wrap Base64 content into standard 64-character lines.→Paragraph CounterTextCount non-empty text paragraphs separated by one or more blank lines.→Password Generator AdvancedGeneratorGenerate 1–100 secure random passwords with 8–256 characters, selectable character sets, similar-character removal, and custom exclusions.→Password Strength CheckerValidatorCheck password strength using length, character variety, repetition, sequences, and common-pattern signals while keeping the result easy to understand.→Phone Number ExtractorTextExtract likely phone numbers from mixed text while preserving their original appearance and order.→Ping TestNetworkSend ICMP echo requests to a public hostname or IP address and review packet loss and round-trip timing.→Port CheckerNetworkTest whether a TCP port on a public hostname or IP address accepts a connection and review connection timing and resolved destination.→Prefix LinesTextAdd the same prefix to every following line while preserving line order and line breaks.→Product Schema GeneratorSeoGenerate Product and Offer JSON-LD for visible product details.→Query String ParserNetworkParse a complete URL or raw query string into structured, readable JSON without changing the original input.→Quote LinesTextWrap every source line in quotation marks while preserving line order and line breaks.→RSA Key GeneratorGeneratorGenerate RSA public and private key pairs in PEM format with selectable key sizes and optional passphrase protection.→Random Password GeneratorGeneratorGenerate strong random passwords with a chosen length for accounts, test data, temporary credentials, and security-focused workflows.→Reading Time CalculatorCalculatorEstimate how long a text takes to read from its word count using a clear words-per-minute model.→Redirect Chain CheckerSeoTrace HTTP redirects, inspect status codes, detect loops, and identify unnecessary redirect hops.→Regex BuilderGeneratorBuild practical regular expressions from common matching requirements.→Regex ExtractorDeveloperExtract all regex matches and capture groups from text.→Regex Match HighlighterDeveloperHighlight every regex match directly inside source text so patterns can be reviewed visually before they are reused.→Regex ReplaceDeveloperReplace regex matches with text or capture-group references.→Regex SplitterDeveloperSplit text with a regular expression and return clean copyable segments without manually editing repeated delimiters.→Regex Tester PRODeveloperTest regular expressions with detailed matches, named groups, offsets, line and column positions, execution timing, and highlighted previews.→Remove All SpacesTextRemove every whitespace character, including spaces, tabs, and line breaks, to create one uninterrupted string.→Remove Duplicate LinesTextKeep the first occurrence of each exact line, remove later duplicates, and preserve the original line order.→Remove Duplicate WordsTextRemove repeated words case-insensitively while keeping each first spelling and the original first-seen order.→Remove Empty LinesTextDelete blank and whitespace-only lines while preserving every populated line in its original order.→Remove Line NumbersTextRemove leading line numbers from text while preserving the remaining line content and order.→Remove NumbersTextRemove numeric digits from text while keeping letters, punctuation, spacing, and line order available for review.→Remove PunctuationTextRemove punctuation characters from text while preserving words, numbers, spaces, and line order for review.→Remove TabsTextRemove tab characters from text while keeping the remaining content and line structure visible for comparison.→Remove WordTextRemove word with a focused browser utility that targets the entered term while keeping the original source visible for careful comparison.→Reverse DNS LookupNetworkLook up the PTR hostname for a public IPv4 or IPv6 address and verify whether the hostname resolves back to the same address.→Reverse LinesTextReverse lines with a focused browser tool that changes only the order of complete lines while keeping every word, number, symbol, and punctuation mark inside each line unchanged.→Reverse TextTextReverse text with a browser utility that returns characters in the opposite order while keeping the original source visible for direct comparison.→Reverse WordsTextReverse words with a focused tool that changes the order of word tokens while keeping the characters inside each individual word readable.→Robots.txt GeneratorSeoBuild a valid robots.txt file with user-agent, allow, disallow, crawl delay, and sitemap rules.→Robots.txt Tester & ValidatorSeoValidate robots.txt syntax, inspect crawler directives, and test whether a URL is allowed for a selected user-agent.→SERP Snippet PreviewSeoPreview a Google-style search result and check title and description lengths.→SHA1 GeneratorGeneratorUse this free SHA1 Generator to generate a SHA-1 hash from exact text, verify whitespace and encoding, and copy a clean hexadecimal digest online.→SHA256 File Checksum GeneratorGeneratorCalculate a SHA-256 checksum for any local file or exact text, then compare it with a published 64-character digest without uploading the file.→SHA512 Generator & SHA256 ComparisonGeneratorGenerate a 128-character SHA-512 digest for long text or hexadecimal key material and compare it with SHA-256 calculated from the same bytes.→SQL BeautifierDeveloperFormat SQL queries with readable clauses, indentation, line breaks, joins, conditions, grouping, and ordering.→SQL FormatterDeveloperFormat SQL statements with clearer indentation and line breaks for review, debugging, documentation, and database development.→SQL MinifierDeveloperCompress SQL queries by removing comments and unnecessary whitespace while keeping statements easy to copy and deploy.→SSH Key GeneratorGeneratorGenerate an RSA SSH public and private key pair with selectable strength, OpenSSH public-key output, and a SHA-256 fingerprint.→SSL Certificate CheckerNetworkInspect a public website TLS certificate, validity period, issuer, subject, SAN hostnames, fingerprint, and trust verification.→Schema Markup GeneratorSeoGenerate validated JSON-LD structured data for common SEO schema types.→Secure Random GeneratorGeneratorGenerate cryptographically secure random bytes, strings, URL-safe values, and integers for development and security workflows.→Sentence Case ConverterTextThis sentence case converter changes irregular capitalization into a sentence-style pattern while keeping the original text available for comparison.→Sentence CounterTextUse this sentence counter to estimate the number of sentence units in articles, essays, notes, product descriptions, and other text.→Set-Cookie ParserDeveloperParse a Set-Cookie response header into its cookie value, scope, expiry, and security attributes.→Shuffle LinesTextShuffle lines into a random order while keeping every line available for review in a separate result.→Sitemap ValidatorSeoValidate XML sitemap syntax, structure, URLs, duplicates, namespaces, and optional metadata.→Slug GeneratorTextSlug Generator creates a clean, lowercase, hyphenated URL slug from any title or phrase. Use this free online tool to review an SEO-friendly result before publishing or changing a permalink.→Sort LinesTextSort lines in ascending alphabetical or natural order while preserving the original source for comparison.→Sort Lines DescendingTextSort lines from Z to A or from higher to lower natural values with a separate result for verification.→Suffix LinesTextAdd the same suffix to every line while keeping the original list visible for careful comparison.→System Prompt BuilderGeneratorSystem Prompt Builder turns one plain-language task into a structured, ready-to-copy system prompt with an automatically selected role, operating rules, safeguards, quality checks, and output requirements.→TOML to JSONConverterConvert practical TOML configuration into formatted JSON.→TOON to JSON ConverterConverterTOON to JSON Converter decodes TOON v4.1 core syntax back into structured JSON with validation of indentation, array lengths, and tabular rows.→TXT Record LookupNetworkTXT Record Lookup retrieves published DNS text records and presents SPF, verification, policy, and other TXT values in a readable report.→Tabs to SpacesTextReplace tab characters with a consistent number of spaces for code, plain text, logs, tables, and formatting cleanup→Text Diff CheckerCompareCompare two text versions line by line and identify additions, removals, and unchanged content.→Text RepeaterTextRepeat text a chosen number of times with predictable separators for testing, templates, sample data, and content preparation→Text StatisticsTextMeasure words, characters, sentences, paragraphs, lines, and estimated reading time in one document overview.→Timestamp ConverterConverterConvert Unix seconds, milliseconds, microseconds and date-time text to UTC, ISO 8601 and selected timezones.→Title Case ConverterTextConvert headings and titles into consistent title case for articles, pages, product names, documents, and publishing workflows→Token GeneratorGeneratorGenerate secure session, CSRF, URL-safe, hexadecimal, and Base64 tokens from cryptographically secure random bytes.→TracerouteNetworkTrace the network path to a public hostname or IP address and review each responding hop and latency.→Trim WhitespaceTextRemove unwanted spaces around every line without changing the meaningful text inside each line.→Twitter Card GeneratorSeoGenerate Twitter Card metadata for link previews on X and compatible platforms.→URL DecoderEncode DecodeDecode valid percent-encoded UTF-8 text while preserving literal plus signs for accurate URL-component inspection.→URL EncoderEncode DecodePercent-encode UTF-8 text for use as one URL component while preserving JavaScript encodeURIComponent-safe characters.→URL ExtractorTextExtract web addresses from text, HTML, logs, exports, and documents for audits, migration, outreach, and review→URL ParserNetworkSplit an absolute URL into scheme, host, port, user information, path, query parameters, and fragment.→URL Query BuilderGeneratorURL Query Builder creates RFC 3986 encoded query strings and complete URLs from readable name and value pairs.→UUID DecoderEncode DecodeDecode a UUID into version, variant, hexadecimal fields, node data, clock sequence, and timestamp information when the version supports it.→UUID GeneratorGeneratorGenerate cryptographically secure UUID v4 or time-ordered UUID v7 identifiers online, one at a time or in bulk, with canonical, uppercase, brace and compact output formats.→UUID ValidatorValidatorValidate canonical UUID syntax, identify versions 1–8, recognize Nil and Max UUIDs, report the variant, and explain format failures.→Unique Word FinderTextFind distinct words, repeated terms, and vocabulary patterns in text for editing, research, SEO, and content analysis→Uppercase ConverterTextConvert letters to uppercase instantly while preserving punctuation, numbers, spacing, and line order.→WHOIS LookupNetworkQuery public WHOIS registry data for a domain and inspect registrar, dates, nameservers, statuses, and raw WHOIS output.→Word CounterTextCount words, characters, sentences, and paragraphs in text for writing, editing, SEO, study, and content planning→Word Frequency CounterTextCount how often every word appears, rank repeated terms, and inspect vocabulary balance in any pasted text.→Words to LinesTextPlace words or separated values on individual lines for lists, imports, cleanup, deduplication, and data preparation→XML CompareCompareCompare two XML documents online, validate their structure, normalize indentation, and review changed elements, attributes, text nodes, and line positions.→XML Escape / UnescapeEncode DecodeXML Escape / Unescape converts reserved XML characters to safe entity references or restores standard XML entities back to readable characters.→XML FormatterDeveloperFormat and indent XML for easier inspection, debugging, configuration review, data exchange, and development workflows→XML MinifierDeveloperXML Minifier removes indentation, line breaks, and optional comments from valid XML to create a compact document while preserving the XML structure.→XML ValidatorValidatorCheck whether XML is well-formed and locate syntax errors such as mismatched tags, invalid nesting, broken attributes and multiple root elements.→XML to CSVConverterConvert repeated XML records into CSV rows for spreadsheets, imports, reporting, and data review.→XML to JSONConverterConvert XML elements, attributes, text values, and repeated nodes into readable structured JSON online.→XPath TesterDeveloperEvaluate XPath 1.0 expressions against XML and inspect matched nodes or typed string, number, and boolean results.→YAML CompareCompareYAML Compare helps you compare two YAML documents, detect added, removed, changed, and type-mismatched values, and review differences with a clear online workflow.→YAML FormatterDeveloperFormat and indent YAML data.→YAML ValidatorValidatorCheck a practical YAML subset for indentation, mappings, sequences, duplicate keys, quotes and scalar syntax, with explicit unsupported-feature errors.→YAML to JSONConverterConvert YAML data to formatted JSON.→YAML to XML ConverterConverterYAML to XML Converter transforms YAML mappings, lists, and scalar values into structured XML for configuration and integration workflows.→cURL BuilderGeneratorBuild secure cURL commands for HTTP requests with methods, headers, query parameters, authentication, and request bodies.→cURL to FetchConverterConvert one cURL HTTP request into reviewable JavaScript Fetch code with method, headers, inline body, redirect policy, timeout, and status handling.→cURL to Go net/httpConverterConvert one cURL HTTP request into complete Go net/http code with method, headers, inline body, redirect policy, client timeout, response close, and status checks.→cURL to PHP cURLConverterConvert one cURL HTTP command into PHP cURL code with method, headers, inline body, redirects, millisecond timeout, execution errors, status checks, and cleanup.→cURL to Python RequestsConverterConvert one cURL HTTP request into Python Requests code with explicit method, headers, inline body, redirect behavior, timeout, and HTTP error handling.→
Generator
Ready
CORS Header Generator
Generate validated CORS response headers for one origin, methods, request headers, exposed response headers, credentials, and preflight caching.
Validate one serialized HTTP or HTTPS origin Normalize and deduplicate method lists Validate request and exposed header names Block credentialed wildcard combinations
CORS is a browser response-sharing policy, not authentication. Never reflect an arbitrary Origin when credentials are enabled.
Private browser processing. Your input is processed on this device and is not sent to the Trexmi server.
INPUT Allowed origin
CORS response headers
Validated origin, methods, request headers, exposed headers, credentials, and cache policy.
CORS
Browser cross-origin policy
REVIEWCORS headers ready
Generated response headersReview before server use
About the tool
What CORS Header Generator does
CORS Header Generator creates response headers used by browsers to decide whether frontend JavaScript may read a cross-origin response. It validates a single serialized origin, HTTP method tokens, request header names, exposed response headers, credential mode, and preflight cache duration.
CORS is not authentication, authorization, CSRF protection, or a firewall. Non-browser clients can still send requests. The server must authenticate requests and verify permissions independently. When credentials are allowed, a wildcard origin is rejected and method or header wildcards must be replaced with explicit values.
How to use
- Choose the allowed origin. Enter one origin such as
https://app.example.com, the wildcard*, or the special valuenull. - List methods. Include only methods the resource accepts, commonly GET, POST, PUT, PATCH, DELETE, and OPTIONS.
- List request headers. Add non-safelisted headers the browser may send, such as Authorization or Content-Type.
- Expose response headers. Name response headers frontend code must read, such as Content-Disposition or X-Request-ID.
- Review credentials and caching. Use an explicit trusted origin for cookies or HTTP authentication, then choose a conservative preflight max age.
Built for the task
Why use CORS Header Generator?
Focused controls, predictable output, and a workflow designed around this exact transformation.
01
Unsafe combinations blocked
Reject wildcard origin, method, and header combinations that conflict with credentialed requests.
02
Validated header tokens
Catch line breaks, invalid names, duplicate values, and malformed origins before deployment.
03
Complete practical set
Generate allow, expose, credentials, max-age, and cache-variation headers.
04
Policy remains explicit
Every generated value comes from a visible field that can be reviewed with backend owners.
Useful answers
Questions about CORS Header Generator
Practical details about input, output, privacy, limits, and the best way to use this tool.
01 What does Access-Control-Allow-Origin contain?
It contains one serialized origin, the wildcard *, or the special value null. It is not a comma-separated origin list.
02 Can I use wildcard origin with credentials?
No. Browser requests whose credentials mode is include require an explicit origin and Access-Control-Allow-Credentials: true.
03 Why is true lowercase in Allow-Credentials?
The Fetch Standard defines the value as the case-sensitive token true. Other capitalization is not equivalent.
04 What is Access-Control-Expose-Headers for?
It lists response headers that browser JavaScript may read beyond the CORS-safelisted response headers.
05 When should I add Vary Origin?
Add it when the response origin is chosen dynamically from a server-side allowlist. For a resource that always returns one static origin or wildcard, it may be disabled.
06 What does Access-Control-Max-Age do?
It controls how long a browser may cache a successful preflight response. Browser caps can differ, and long caching delays policy changes.
07 Does CORS protect an API from unauthorized requests?
No. It controls browser response sharing. The API still needs authentication, authorization, input validation, CSRF defenses where relevant, and rate limits.
08 Why can a correct header set still fail?
The actual server must return the headers on the relevant response, including errors and preflight OPTIONS responses. Redirects, proxies, caches, and route-specific configuration can change the result.
Examples
Allow one frontend origin
A specific-origin API policy includes preflight and readable-response metadata.
Input
Origin: https://app.example.com Methods: GET, POST, OPTIONS Request headers: Content-Type, Authorization Expose: X-Request-ID Credentials: off Max age: 600
Output
Access-Control-Allow-Origin: https://app.example.com\nAccess-Control-Allow-Methods: GET, POST, OPTIONS\nAccess-Control-Allow-Headers: Content-Type, Authorization\nAccess-Control-Expose-Headers: X-Request-ID\nAccess-Control-Max-Age: 600\nVary: Origin
Generate a public read-only policy
A wildcard policy omits Vary Origin and does not allow credentialed browser access.
Input
Origin: * Methods: GET, OPTIONS Request headers: (empty) Credentials: off Max age: 300
Output
Access-Control-Allow-Origin: *\nAccess-Control-Allow-Methods: GET, OPTIONS\nAccess-Control-Max-Age: 300
Allow credentialed requests safely
The full result also includes the explicit method and request-header lists.
Input
Origin: https://account.example.com Methods: GET, POST Request headers: Content-Type, X-CSRF-Token Credentials: on
Output
Access-Control-Allow-Origin: https://account.example.com\nAccess-Control-Allow-Credentials: true\nVary: Origin
Reject an invalid origin list
Access-Control-Allow-Origin does not accept a comma-separated list of origins.
Input
Origin: https://a.example.com, https://b.example.com Credentials: off
Output
Error: Allowed origin must be one serialized HTTP/HTTPS origin.
One allowed origin per response
Access-Control-Allow-Origin accepts one serialized origin, *, or null. A serialized origin contains scheme, host, and optional port without credentials, a path, trailing slash, query, or fragment. Supporting several trusted origins requires server logic that compares the request Origin with an allowlist and emits the one approved origin.
Do not reflect arbitrary request origins. Reflection without a trusted allowlist removes the intended access boundary, especially when credentials or sensitive response data are involved.
Methods, request headers, and exposed response headers
Access-Control-Allow-Methods and Access-Control-Allow-Headers answer a browser preflight request. They should describe the endpoint, not every capability of the whole server. Access-Control-Expose-Headers controls which response headers browser scripts can read.
The generator validates HTTP token syntax, removes duplicates, and normalizes methods to uppercase. It cannot determine whether the application actually supports the listed methods or headers.
Credentialed CORS
Credentials can include cookies and HTTP authentication. With credential mode include, wildcard allow-origin is invalid and allow-credentials must be exactly lowercase true. Wildcards for methods and header lists also do not act as wildcards for credentialed requests, so this generator requires explicit lists.
CORS credentials do not replace session security. Review SameSite cookies, CSRF protection, origin checking, authentication, and authorization separately.
Preflight caching and Vary Origin
Access-Control-Max-Age can reduce repeated OPTIONS requests but may cause old policy to remain cached. Choose a duration compatible with deployment rollback and incident response. Browser-specific caps may shorten the effective lifetime.
Use Vary: Origin when a cache can receive different Access-Control-Allow-Origin values for the same resource. It is unnecessary when the resource always sends a static wildcard or static origin on every response.
Generator limits and deployment checks
The output is a header block, not server configuration. It does not create OPTIONS routes, authenticate users, test a live preflight, validate CDN behavior, choose a framework middleware order, or prove that error responses include the same CORS policy.
After deployment, inspect the live response with HTTP Header Checker. Build a separate browser content policy with CSP Policy Builder; CSP and CORS solve different problems.
Official CORS and HTTP references
Review the Fetch Standard CORS protocol and HTTP Semantics RFC 9110.