Test regular expressions with live match highlighting, groups and flags.
Write a pattern, pick flags (g, i, m, s), and see every match highlighted live with capture groups and a full match list. Includes a replace preview.
100% client-side — zero uploads, maximum privacy
Instant results — no waiting for server processing
Secure — your data never leaves your browser
Free to use — no sign-up required
Handles real-world edge cases — malformed input, nested structures, large payloads
Syntax highlighting for easier reading and debugging
Copy-to-clipboard in one click — paste directly into your editor or terminal
Works with JSON, YAML, XML, CSV, Base64, JWT, and more
No file size limits for text processing
Test and debug regular expressions before adding them to code
Validate user input patterns like emails, phones, and URLs
Build complex regex for log parsing and data extraction
Learn regex with real-time match highlighting
Find and replace patterns across large text blocks
JavaScript (ECMAScript) regex, including lookahead, lookbehind and named groups.
Make sure the flags match your intent — 'g' for all matches, 'i' for case-insensitive, 'm' for multi-line.
Format, minify and validate JSON with syntax error details and document stats.
Convert CSV to JSON and JSON to CSV with delimiter and quote support.
Encode text or files to Base64 with URL-safe and Unicode support.
Decode Base64 strings back to text or files with Unicode support.
Percent-encode URL strings for query parameters and paths.
Decode percent-encoded URLs and query strings instantly.