Developer Tool
Regex Tester
Test JavaScript regular expressions with live match highlighting, capturing groups, and optional replacement preview. All processing happens locally in your browser.
Your data is processed locally in your browser and is never uploaded.
More Developer Tools
Free browser-based tools for developers. No data leaves your device.
- Dev Tool
JWT Decoder
Decode JWT tokens locally without sending data to any server.
Open - Dev Tool
JSON Formatter
Beautify, minify, and validate JSON with indentation options.
Open - Dev Tool
Base64 Encoder/Decoder
Encode and decode Base64 and Base64URL with Unicode support.
Open - Dev Tool
UUID Generator
Generate cryptographically secure UUID v4 identifiers.
Open - Dev Tool
Cron Expression Generator
Build and humanize standard five-field Unix cron expressions.
Open - Dev Tool
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates.
Open - Dev Tool
URL Encoder/Decoder
Encode and decode URL components and full URIs.
Open - Dev Tool
SQL to JSON Converter
Convert SQL INSERT statements to structured JSON.
Open - Dev Tool
CSV to JSON Converter
Parse CSV data into JSON with nested key support.
Open
FAQ
- Which regex engine does this tool use?
- This tool uses the JavaScript RegExp engine built into your browser. Behavior matches what you'd get in Node.js or browser JavaScript.
- What regex flags are supported?
- All standard JavaScript flags: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), and y (sticky).
- How are zero-length matches handled?
- Zero-length matches (like those from lookaheads or empty patterns) are skipped and the index is advanced to prevent infinite loops.
- Is my data sent to a server?
- No. All regex execution happens locally in your browser. No data leaves your device.