Real Local Tools

Regex Tester

Runs locally

Test regular expressions with live highlighting, match groups, replacement and a pattern cheat sheet.

//g
Flags

Matches
Common patterns
Related tools
View all (10)
JWT Decoder
Decode JSON Web Tokens locally: inspect the header, payload claims and expiry — the token never leaves your browser.
JSON Formatter & Validator
Format, validate, beautify or minify JSON instantly — right in your browser.
Base64 Encoder / Decoder
Convert text to Base64 and back, with full Unicode support — all in your browser.
URL Encoder / Decoder
Encode and decode URLs and URI components safely — instantly, in your browser.
UUID Generator
Generate random v4 UUIDs in bulk — cryptographically random, right in your browser.
Unix Timestamp Converter
Convert Unix epoch timestamps to human-readable dates and back — with live current time.
Write a regular expression, pick your flags, and watch matches highlight in real time. Inspect every capture group with its index, try replacements, and grab common patterns from the built-in cheat sheet. Everything runs locally in your browser.
Frequently asked questions
Which regex syntax does it use?
JavaScript's — the exact engine your browser ships, including flags (g, i, m, s, u, y), lookaheads and named capture groups. The built-in cheat sheet offers common patterns to start from.
Can I test replacements, not just matches?
Yes. Enter a replacement string with $1, $& style backreferences and you will see the replaced result alongside the highlighted matches and capture groups.
Is my test text uploaded?
No. Matching runs locally in your browser's RegExp engine.