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Regex Tester

Test JavaScript regular expressions: matches, groups, replacement and protection from runaway patterns.

Examples

Regular expression

Pattern

//g

Flags

gglobal

iignore case

mmultiline

sdot all

uUnicode

ysticky

dindices

vunicodeSets

Test text

Size: 0 BLines: 0Characters: 0

Wrap lines

Result

Enter an expression to see matches.

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How to use

Enter a pattern and toggle flags (g, i, m, s, u, y, d, v).
Paste test text — matches are highlighted and the list shows indices and groups.
Switch to “Replace” to see the substitution result with $1, $<name>, $& and so on.
Try the ready-made examples to get started quickly.

Your browser’s own JavaScript regex engine is used, so behaviour matches real JS code.
Matching runs in a background thread and is aborted after ~500 ms — a catastrophic pattern cannot freeze the page.
Limits: text up to 1 MiB and at most 10,000 listed matches. Flags u and v cannot be combined.

Free online tools for developers and QA. Part of the Geekjoy ecosystem.

Tools run locally: the data you enter never leaves your browser.

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