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Focused tools

10 regex jobs

Worker deadline

500 ms

Private Regex tools with bounded browser execution

Test, extract, replace, split, filter, inspect captures, validate syntax, escape literals, explain structure, and compare ECMAScript flags without uploading text.

Every executing pattern runs in a disposable browser worker.

Choose a Regex job

Each route has a distinct matching, transformation, parsing, or comparison contract.

Regex TesterAnswer whether a pattern matches and inspect the first match, offset, captures, and named groups.Open tool
Regex Match ExtractorEnumerate one match or all global matches with offsets and capture data up to a hard result count.Open tool
Regex ReplacerTransform text with JavaScript replacement-string semantics while keeping the global-versus-first choice visible.Open tool
Regex SplitterTurn a delimiter pattern into a structured parts list with an explicit empty-part policy.Open tool
Regex Line FilterApply one pattern independently to each line and choose whether matching or nonmatching lines survive.Open tool
Regex Capture GroupsSee the full first match beside every numbered and named capture, including groups that did not participate.Open tool
Regex ValidatorParse pattern and flags against ECMAScript 2025 grammar without applying the expression to user text.Open tool
Regex Literal EscaperConvert user text into a pattern fragment that matches the text literally instead of interpreting regex syntax.Open tool
Regex ExplainerTurn a valid pattern into a position-aware inventory of its structural regex features.Open tool
Regex Flags ComparisonRun one unchanged pattern against one unchanged input under baseline and comparison flags, then inspect both match lists.Open tool

Start with a first-match test

Confirm a match and inspect its boundaries and captures before moving to extraction, replacement, or line filtering.

Input

Enter a pattern without / delimiters, optional flags, and the text to test.

Local

Use ECMAScript flags such as g, i, m, s, u, v, y, or d.

First-match report

Submit the example or replace it with your own values. User matching runs only in a disposable browser worker.

A safer regex workspace

A regular expression can consume a browser thread for far longer than its size suggests. User matching therefore never runs on the interface thread.

Patterns are limited to 4 KiB, text to 256 KiB, replacements to 64 KiB, results to 1 MiB, matches and split parts to 10,000, and line filters to 20,000 lines.

The timeout protects this page, not every future deployment. Treat it as an execution boundary rather than a universal performance verdict.