Regex Tester
Test a regular expression against your own text and see every match highlighted as you type, with capture groups color coded and broken down match by match. Toggle any JavaScript regex flag, read the exact error when a pattern is invalid, and copy all matches as a list.
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Quick reference
\d \w \sdigit, word character, whitespace\D \W \Sanything but a digit, word character, whitespace.any character except a newline[abc]one of a, b or c[^abc]any character except a, b or c[a-z]a character from a to za|ba or b^ $start and end of the text, or of a line with the m flag\bword boundarya* a+ a?zero or more, one or more, optionala{2,4}two to four timesa+?lazy, match as little as possible(…)capture group(?<name>…)named capture group(?:…)group without capturing(?=…) (?!…)lookahead, positive and negative(?<=…) (?<!…)lookbehind, positive and negative\1back reference to group 1\n \tnewline, tab\.a literal dot, escape any special characterNext steps
Send this tool's output straight into another tool.
Replace text in two modes: plain find and replace all, or regular expressions with flag controls and capture group references like $1.
Convert text into every case at once: title case in the APA, AP, Chicago, MLA, Bluebook, AMA and NYT styles, sentence case, upper, lower, camelCase, snake_case, kebab-case and more, each with its own copy button.
Count words, characters, sentences, paragraphs, lines and more as you type, with estimated reading and speaking time.
Remove duplicate lines from a list or text, keeping the first occurrence. Optionally ignore case and whitespace, or drop blank lines too.
Paste a UUID to see what it carries: version, variant, and for time-based versions the exact timestamp, clock sequence and node. Also shows the raw bytes, the 128-bit integer and the URN form.
Decode Base64 to text or encode text to Base64. Paste into the top box, read the result below, and flip the direction with one click. Handles Unicode correctly, reads URL-safe Base64, and shows binary payloads as a hex dump you can download.
Convert between scientific notation and full numbers as you type. Reads 1.23e5, 1.23 × 10^5 and plain numbers, shows the value written out, in normalized scientific notation and in engineering notation, and can round to any number of significant digits.
Sort the lines of a text alphabetically, naturally, by length, by numeric value or shuffled. Reverse the order with a switch, and optionally trim lines, drop blank lines and remove duplicates in the same pass.
Convert a color between HEX, RGB, HSL, HSV, HWB, CMYK, OKLCH and OKLAB. Type into any field and the others update as you go, or pick the color visually. Reads CSS color syntax and keeps alpha where the format supports it.
Check two colors against the WCAG contrast rules. Type or pick a text and a background color, read the contrast ratio, see which AA and AAA checks pass, preview real text at the sizes WCAG distinguishes, and get suggested fixes when a check fails.
Create a QR code for text, a link, an email, a phone number, an SMS, Wi-Fi access or a contact card. Set the error correction level, size, margin and colors, then download it as PNG or SVG or copy it straight to the clipboard.
Paste a cron expression and get a plain English explanation, a field by field breakdown and the next times it would run, in your local timezone or UTC. Reads five field crontab syntax, six fields with seconds, names like MON and macros like @daily.
Work out an IPv4 or IPv6 network from an address with a prefix or netmask: network and broadcast addresses, usable host range, subnet mask, wildcard mask and address type. Adjust the prefix with a slider, read the binary breakdown, and split the network into smaller subnets.
Hash text or a file with MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE2, BLAKE3, CRC32 and more, all computed live as you type. Compare against an expected checksum and copy any digest.
Verify a checksum online: drop a file, paste the expected checksum and see instantly whether they match. The hash type is detected from the checksum itself, covering MD5, SHA-1, SHA-256, SHA-512, BLAKE3, CRC-32 and more, and sha256sum lines or whole checksum files can be pasted as-is.
Encode text for use in URLs or decode percent-escaped strings back to readable text. Choose component, full-URL or form encoding, unwrap double-encoded strings, and break a URL into its parts with every query parameter decoded.
Convert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to readable dates in your local time, UTC or any timezone, and turn any date back into a timestamp. Shows the live current timestamp and relative time.
Escape text into HTML entities or decode entities back to plain text. Choose named or numeric entities, escape only the unsafe characters or everything outside ASCII, and read the result live.
Paste a JSON Web Token to see its header and payload as formatted JSON, with the token color coded so each part maps to its output. Explains the registered claims, shows expiry as readable dates, flags expired tokens and can verify the signature with a secret or public key.
Compress text or a file with gzip, deflate, brotli or Zstandard and see the size before and after, the compression ratio and how long it took. One click tries every method and recommends the smallest result.
Decompress gzip, deflate, brotli or Zstandard data from a file or pasted Base64 and read the result as text or download it. Detects the format from the magic bytes where possible, with a manual override.
Paste anything that looks encoded and this tool works out what was used and undoes it, layer by layer. The whole BaseXX family from Base16 to Base85, binary, URL escapes, HTML entities, ROT13 and gzip, Brotli or Zstandard compression are detected in any combination, and every step of the chain is reported.
Escape or unescape a string for JSON, JavaScript, regex, shell, SQL, CSV, XML and more. Paste text, pick the target format and copy the result, in either direction.
Paste a PEM certificate to see its subject, issuer, validity dates, subject alternative names, key details, fingerprints and extensions in plain view.
Paste a 2FA secret or an otpauth:// link and watch the one-time codes tick live, with a countdown to the next code. Supports the digit counts, periods and algorithms real authenticators use.
Format code in JavaScript, TypeScript, JSON, JSON5, HTML, Vue, CSS, SCSS, LESS, Markdown, YAML, GraphQL, XML and SQL. Pick tabs or spaces, set the indent width, and format the input in place with one click.
Reveal the characters you can't see in a text: zero-width spaces, non-breaking spaces, bidi marks, control characters and CRLF versus LF line endings. Inspect every occurrence and clean them out with a click.
Test a regular expression against your own text and see every match highlighted as you type, with capture groups color coded and broken down match by match. Toggle any JavaScript regex flag, read the exact error when a pattern is invalid, and copy all matches as a list.