Useful Regex Tools starting points

Jump into a common task, then use the full directory below for more specialized tools.

Regex Builder & Generator Regex Code Generator Regex Replace Tester Regex Splitter Regex Tester Regex Extractor

16 browser-local regex tools

Regex Tools

Test, explain, build, transform, inspect, and reuse JavaScript regular expressions with browser-local tools and explicit flavor limits.

Move from a pattern idea to tested, understandable regex

The hub makes the main workflows visible first, then keeps the full specialist catalog below for direct access.

Test & debug

Start with real sample text, captures, replacements, bounded performance checks, and repeatable cases.

Regex TesterPaste a JavaScript pattern and test string, inspect exact match ranges and groups, then review pattern structure or move into unit-test and code-generation workflows without sending data to a server.Regex Replace TesterEnter a pattern, flags, replacement string, and source text to preview first-match or global replacement without blocking the main UI.Regex Test Case RunnerBuild a small repeatable regex test set in the browser and keep flavor differences explicit before porting the pattern to another language.Regex Performance TesterMeasure one bounded browser sample without treating its timing as a guarantee for other browsers, inputs, engines, or adversarial strings.Regex Capture Group InspectorRun a pattern globally and inspect capture-group values per match, including named groups when the browser supports them.

Understand the pattern

Inspect structure and readable token meaning before changing or porting a regex.

Regex ExplainerUse token-level explanations to understand a pattern, while keeping engine flavor and runtime-complexity limits explicit.Regex Pattern InspectorReview token-level regex structure locally and use the dedicated explainer for readable token meanings without treating static hints as a runtime complexity proof.Regex Character Class BuilderCombine digits, lowercase, uppercase, word, whitespace, custom characters, and optional negation into a copy-ready character class.Regex Builder & GeneratorGenerate a starting pattern locally and review its exact structure instead of assuming a recipe proves real-world validity.

Extract, filter & split

Apply a pattern to focused text-processing jobs without turning every task into one overloaded tester.

Regex ExtractorRun a regular expression safely in a worker and export matching substrings as plain text or JSON with indexes and groups.Regex Line FilterFilter multiline text line by line with a JavaScript regex and choose whether to keep matching or non-matching lines.Regex SplitterEnter a delimiter pattern and flags, then split source text into parts locally with a worker timeout guard.Regex Match CounterCount global matches, unique matched values, longest match, and zero-length matches locally without uploading text.

Generate & move to code

Escape literals, convert globs, and create starter snippets while keeping flavor differences visible.

Regex Escape ToolConvert arbitrary literal text into a JavaScript-regex-safe literal pattern, with optional slash escaping for /pattern/ notation.Glob to Regex ConverterConvert *, **, and ? glob syntax into regex with optional path-aware slash handling and explicit anchoring.Regex Code GeneratorCopy starter snippets locally and review target-engine syntax differences before using the result in production code.

All Regex Tools

Regex Tester

Test JavaScript regular expressions in a worker-guarded live workspace with highlighted matches, capture details, navigation, token explanation, static risk hints, examples, and connected test/code tools.

Regex Replace Tester

Test JavaScript regular-expression replacements safely in a browser worker.

Regex Extractor

Extract all regex matches from text with positions and capture data.

Regex Splitter

Split text using a JavaScript regular expression as the delimiter.

Regex Escape Tool

Escape literal text so regex metacharacters match themselves.

Regex Match Counter

Count total and unique regex matches with frequency statistics.

Regex Capture Group Inspector

Inspect numbered and named capture groups for every regex match.

Regex Character Class Builder

Build a regex character class from common ranges and custom literal characters.

Regex Test Case Runner

Run should-match and should-not-match JavaScript regex cases locally, then inspect the same pattern structure, flags, groups, and heuristic risk signals.

Glob to Regex Converter

Convert simple glob wildcards into an anchored JavaScript regular expression.

Regex Line Filter

Keep matching or non-matching lines using a regular expression.

Regex Pattern Inspector

Inspect JavaScript regex groups, classes, escapes, quantifiers, anchors, alternation, lookarounds, backreferences, and heuristic backtracking signals in a connected local workspace.

Regex Performance Tester

Benchmark a JavaScript regular expression in a worker-guarded local test while keeping static backtracking warnings, structure metrics, and correctness tools close at hand.

Regex Builder & Generator

Build practical JavaScript regular expressions from common recipes, then inspect every generated token, group, class, quantifier, and static risk signal before reuse.

Regex Code Generator

Generate starter regex code for multiple languages while keeping JavaScript-source structure, flavor portability warnings, and a token explainer visible.

Regex Explainer

Explain JavaScript regex tokens, groups, assertions, classes, anchors, quantifiers, alternation, backreferences, and heuristic risk signals locally.