01
Focused workflow
One clear operation produces an easy-to-review result.
Start typing to search 126 tools.
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.→BCrypt Hash GeneratorGeneratorUse this free BCrypt Hash Generator to create a salted password hash with a configurable cost and copy it for secure password-storage testing.→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 Base64 into readable Unicode text for debugging, data recovery, API checks, configuration review, and development work→Base64 EncoderEncode DecodeEncode Unicode text as Base64 for data transport, API payloads, configuration values, testing, and development tasks→CRC32 GeneratorGeneratorGenerate CRC32 checksums from exact text in hexadecimal and decimal formats for compatibility checks, fixtures, archives, and data-transfer testing.→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 CSV structure, detect inconsistent rows, and identify quoting or delimiter problems before import.→CSV ViewerTableOpen CSV data in a clear table, inspect rows and columns, and review structured records before using them elsewhere.→CSV to JSON: Best Free Online ConverterDeveloperCSV to JSON converts CSV rows into structured JSON for APIs, imports, scripts, testing, and migration. Review headers, values, quoting, and the final result before copying the output.→Case ConverterTextConvert text to camelCase, PascalCase, snake_case and more.→Certificate DecoderEncode DecodeDecode X.509 PEM certificates and inspect subject, issuer, validity, fingerprints, SAN entries, signature algorithm, 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.→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.→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 Status Code LookupNetworkLook up an HTTP response code and understand its official class, common meaning, and practical debugging context.→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.→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 FormatterDeveloperFormat and indent JSON so objects, arrays, keys, and values are easier to inspect, debug, validate, and share→JSON MinifierDeveloperMinify formatted JSON into a compact single-line representation for APIs, storage, testing, and data transfer.→JSON Schema ValidatorValidatorJSON Schema Validator checks JSON against a schema, reports exact validation paths, and helps you review required fields, types, formats, arrays, and nested objects online.→JSON SorterDeveloperUse this free JSON Sorter to alphabetize object keys recursively while preserving values, nested structures, and array order online.→JSON ValidatorValidatorValidate JSON syntax and identify parsing errors before using data in an API, application, import, or configuration.→JSON to CSVConverterConvert a JSON array of objects into CSV rows for spreadsheets, reports, imports, and structured-data review.→JSON to YAMLConverterConvert JSON data to readable YAML.→JWT DecoderEncode DecodeDecode JWT header and payload data for inspection without verifying the token signature or authenticity.→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.→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.→Lowercase ConverterTextConvert cased letters to lowercase while preserving punctuation, spaces, and line breaks.→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.→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.→Number ExtractorTextExtract signed integers and decimal values from mixed text while preserving their original order.→OpenAPI ValidatorValidatorOpenAPI Validator reviews OpenAPI documents for structural and reference problems, helping teams detect invalid paths, operations, schemas, parameters, and responses online.→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 strong random passwords with custom length, character sets, exclusions, quantity controls, and secure browser-friendly output.→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.→Prefix LinesTextAdd the same prefix to every following line while preserving line order and line breaks.→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.→Regex TesterDeveloperTest regular expressions against sample text.→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 NumbersTextStrip common leading line-number formats while leaving the remaining line content intact. Use it on copied transcripts, numbered exports, documentation and code samples.→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 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.→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 GeneratorGeneratorUse this free SHA256 Generator to generate a SHA-256 hash from exact text, verify whitespace and encoding, and copy a clean hexadecimal digest online.→SHA512 GeneratorGeneratorUse this free SHA512 Generator to generate a SHA-512 hash from exact text, verify whitespace and encoding, and copy a clean hexadecimal digest online.→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.→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.→Shuffle LinesTextShuffle lines into a random order while keeping every line available for review in a separate result.→Slug Generator: Best Free Online ToolTextSlug 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.→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 timestamps and date-time values.→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.→Trim WhitespaceTextRemove unwanted spaces around every line without changing the meaningful text inside each line.→URL DecoderEncode DecodeDecode percent-encoded URLs and query values into readable text for debugging, analysis, testing, and content review→URL EncoderEncode DecodeEncode text and reserved characters for query strings, links, redirects, API requests, and safe URL handling→URL ExtractorTextExtract web addresses from text, HTML, logs, exports, and documents for audits, migration, outreach, and review→URL ParserNetworkUse this free URL Parser to split any absolute link into scheme, host, port, path, query parameters, and fragment online.→UUID DecoderEncode DecodeDecode a UUID into version, variant, hexadecimal fields, node data, clock sequence, and timestamp information when the version supports it.→UUID GeneratorGeneratorGenerate random UUID version 4 identifiers for development, databases, fixtures, APIs, testing, and content-management workflows.→UUID ValidatorValidatorValidate UUID syntax online, identify versions 1 through 8, confirm the RFC variant, and understand why an identifier is invalid.→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.→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 Formatter: 7 Amazing Proven TipsDeveloperFormat and indent XML for easier inspection, debugging, configuration review, data exchange, and development workflows→XML Validator: 7 Amazing Proven TipsValidatorValidate XML structure and syntax to find malformed tags, broken nesting, and parsing problems before import or deployment→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.→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 ValidatorValidatorValidate YAML syntax and structure.→YAML to JSONConverterConvert YAML data to formatted JSON.→
Developer
Ready
Regex Tester
Test regular expressions against sample text.
Focused input and output workflow Unicode-aware processing Copy-ready result Clear validation messages
INPUT Developer source value *
Paste the source value for this specific transformation. Example: Trexmi developer sample
Result
Result ready to review and copy.
About the tool
What Regex Tester does
Regex Tester is a focused online utility that helps you test a regular expression against realistic text and inspect every match, capture group, and character offset.
The tool keeps the original input visible and places the result in a separate review area. This makes it easier to verify complete values, compare changes, catch malformed input, and copy only the result you intend to use.
Use realistic sample data, review the beginning and end of the output, and test production-sensitive results in a safe environment before deployment.
How to use
- Add input. Paste complete representative content.
- Choose settings. Select only the options required for the task.
- Run the tool. Process the input once.
- Review the output. Compare the result with the source.
- Test and copy. Use important output only after verification.
Built for the task
Why use Regex Tester?
Focused controls, predictable output, and a workflow designed around this exact transformation.
02
Visible source
Original input remains available for comparison.
03
Copy-ready output
The separate result can be reviewed before copying.
04
Safer validation
Clear checks reduce avoidable mistakes.
Useful answers
Questions about Regex Tester
Practical details about input, output, privacy, limits, and the best way to use this tool.
Answer 01
What does Regex Tester do?
It helps you test a regular expression against realistic text and inspect every match, capture group, and character offset.
Answer 02
Is Regex Tester free to use?
The tool can be used within the active Trexmi plan limits.
Answer 03
Does it change my original input?
No. The result is generated separately so you can compare it with the source.
Answer 04
Does it support Unicode text?
Yes. Common non-Latin characters and symbols are preserved where the selected operation allows them.
Answer 05
Why can input fail?
Malformed syntax, incomplete values, unsupported options, hidden characters, or exceeded limits can cause validation errors.
Answer 06
Can I process large input?
Yes within the active plan limits. Start with a representative sample when troubleshooting.
Answer 07
Should I test the output?
Yes. Always test important output in the destination application before production use.
Answer 08
Can I use confidential data?
Avoid passwords, private keys, tokens, personal records, and production secrets unless you fully trust the environment.
What does Regex Tester do?
It helps you test a regular expression against realistic text and inspect every match, capture group, and character offset.
Is Regex Tester free to use?
The tool can be used within the active Trexmi plan limits.
Does it change my original input?
No. The result is generated separately so you can compare it with the source.
Does it support Unicode text?
Yes. Common non-Latin characters and symbols are preserved where the selected operation allows them.
Why can input fail?
Malformed syntax, incomplete values, unsupported options, hidden characters, or exceeded limits can cause validation errors.
Can I process large input?
Yes within the active plan limits. Start with a representative sample when troubleshooting.
Should I test the output?
Yes. Always test important output in the destination application before production use.
Can I use confidential data?
Avoid passwords, private keys, tokens, personal records, and production secrets unless you fully trust the environment.
How Regex Tester works
Regex Tester reads the supplied values, applies one clearly defined operation, and returns a separate result. The source is not silently replaced, which supports safer comparison and correction.
The processor validates the most important input conditions and reports understandable errors instead of returning an incomplete result.
Common Regex Tester use cases
Use Regex Tester during development, content preparation, testing, troubleshooting, migration, documentation, and quality assurance.
Representative examples are more useful than tiny artificial samples because they reveal Unicode, whitespace, nesting, quoting, and boundary issues.
Prepare the input
Copy the complete source and preserve an untouched backup. Remove accidental rich-text formatting and confirm that the first and final characters are present.
For confidential workflows, replace real credentials, customer details, tokens, and production identifiers with safe test values.
Review the result
Inspect every important section rather than only the first line. Verify formatting, data types, order, capitalization, delimiters, offsets, and any security-sensitive values.
Test the result in the receiving application when compatibility matters because that system remains authoritative.
Troubleshooting
Reduce failing input to the smallest example that reproduces the problem, then restore content gradually.
This method isolates the exact line, symbol, option, or value responsible for unexpected output.
Privacy and limitations
Browser utilities simplify routine work but do not replace standards documentation, security review, or destination-specific validation.
Do not paste private keys, passwords, personal records, or production secrets into an environment you do not trust.
Related Trexmi tools
Continue with the first related tool or the second related tool.
External regex references
Use the MDN regular expressions guide and the ECMAScript RegExp specification when you need authoritative syntax, flags, matching behavior, and compatibility details.