Regex Visualizer & Explainer — Understand Regular Expressions Online
Test and explain regular expressions. Paste a pattern and test string — see all matches highlighted with positions, plus a plain-English breakdown of every token in your regex. 100% local.
Last updated:
CommentsPaste any regex to see a token-by-token breakdown in plain English — anchors, quantifiers, groups, character classes — plus match highlights on your test string.
0 matches found
Pattern explanation
+ → One or more of the preceding token (greedy). + → One or more of the preceding token (greedy). \\ → Literal backslash. . → Any single character (except newline).
What is Regex Visualizer?
Reading a regex someone else wrote is one of the most frustrating developer experiences. A single regex like ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ is dense and intimidating. The Regex Visualizer breaks it down token by token — '^ means start of line', '[a-zA-Z0-9._%+-] means a character class matching letters, digits, and email-safe symbols' — making it readable by anyone.
How to visualize a regex
- 1Enter your regex pattern.
- 2Type a test string to see matches highlighted with position indices.
- 3Read the token-by-token explanation in the panel below.
Frequently Asked Questions
How is this different from Regex Tester?
Regex Tester is for writing and debugging patterns in real time. Regex Visualizer explains each token in human-readable English — useful when you're reading someone else's regex or learning the syntax.
What tokens does it explain?
Anchors (^ $), quantifiers (* + ? {}), character classes ([a-z] [^abc] \d \w \s), groups (capturing, non-capturing, lookahead/lookbehind), alternation (|), and escape sequences.
Does it support all regex flavors?
It supports standard ECMAScript (JavaScript) regex syntax, which covers the common subset used by most programming languages.
Try Next
Meta Tag Preview
Preview how your page will appear in Google search results and social share cards on Facebook, Twitter/X, and LinkedIn. Parses <title>, meta description, canonical, and full Open Graph / Twitter Card tags with diagnostics. 100% local.
Related Tools
HTTP Status Codes
Complete reference of HTTP status codes with meanings, use cases, and RFC citations. Search 60+ codes from 100 Continue to 511 Network Authentication Required.
cURL Converter
Convert cURL commands to Python (requests), JavaScript (fetch), Node.js, Go (net/http), PHP, or Java (HttpClient). Parses -H, -d, --data-urlencode, -F, -u, --json and more. 100% local.
URL Parser
Parse any URL into scheme, host, port, path, and query parameters — or build a URL from scratch with a form. Great for debugging redirect chains, tracking pixels, and OAuth flows. 100% local.
CIDR Calculator
Calculate IPv4 subnets from CIDR notation online. Get network address, broadcast, netmask, wildcard, usable host range, IP class, and binary representation. 100% local — nothing leaves your browser.
Color Converter
Convert colors between HEX, RGB, HSL, and HSV instantly with a live color preview and copy-ready CSS strings. Free, no signup, runs entirely in your browser.
User Agent Parser
Parse User-Agent strings to identify browser, engine, operating system, and device. Instantly see what your own browser sends.