Explain This Regex
Paste a regular expression — get what it matches, a token-by-token breakdown, and real examples. Free, no signup.
Frequently Asked Questions
What does this tool do?
Paste a regular expression and an AI explains in plain English what it matches, walks through it token by token, and shows example strings that do and don't match — so you can understand a pattern you didn't write.
Is it really free?
Yes — no signup, no credit card. There's a fair-use rate limit so the tool stays available for everyone.
Which regex flavors does it understand?
The common ones — JavaScript, PCRE, Python re, Java, Go and similar. Most syntax overlaps; the explainer notes the flavor when the pattern uses flavor-specific features.
Can it also test my regex against input?
This tool explains a pattern in words. To test matches interactively with live highlighting, use the Regex Tester — it runs entirely in your browser.
More free tools
Paste an error or stack trace and get a plain-English explanation, the likely cause, and how to fix it.
JSON Formatter & ValidatorFormat, validate, and beautify JSON data instantly. Catch syntax errors with line numbers.
Base64 Encode / DecodeEncode text to Base64 or decode Base64 strings back to plain text. Supports UTF-8.
Epoch / Unix Timestamp ConverterConvert between Unix timestamps and human-readable dates. Supports seconds and milliseconds.
Tired of debugging in production?
Bugsly catches errors before your users do — with AI-powered explanations and instant fixes.
Get Started Free