Test, build, explain, convert and benchmark regular expressions.
Live regex tester with match highlighting and group capture.
Step through regex exec() calls with timings and group captures.
Token-by-token plain-English explanation of any regex pattern.
Color-coded nested tree visualization of a regex pattern.
Plain-text ASCII tree view of a regex pattern, ready to copy.
Compare the same regex pattern across every flag side-by-side.
Count matches in text or an uploaded file with frequency stats.
Benchmark two regex patterns side-by-side with iteration sweeps.
Spot regex patterns vulnerable to catastrophic backtracking.
See where ^, $ and word boundaries land in your sample text.
Visually build regex patterns from named building blocks.
Infer a regex pattern from example strings that should all match.
Escape literal text so special regex characters lose their meaning.
Strip backslash-escapes from a regex pattern to reveal the literal text.
Convert numbered capturing groups into named groups.
Apply safe rewrites to shrink a regex without changing what it matches.
Compare two regex patterns structurally and by behaviour on sample text.
Generate random strings that match a given regex pattern.
Apply a regex with replacement template, with $1, $2, $<name> support.
Apply many regex replacement rules in sequence to the same text.
Translate regex syntax between JavaScript and PCRE.
Translate regex syntax between JavaScript and Python re.
Translate regex syntax between JavaScript and java.util.regex.Pattern.
Translate regex syntax between JavaScript and .NET.
Translate regex syntax between JavaScript and Go's RE2 regexp package.
Translate regex syntax between JavaScript and Ruby's Onigmo engine.
Translate regex syntax between JavaScript and Rust's regex crate.
Translate regex syntax between JavaScript and Perl.
Translate regex syntax between POSIX BRE/ERE and PCRE.
See which engines (JS, PCRE, Python, Java, .NET, Go, Ruby, Rust) accept a pattern.
Generate JavaScript code snippets from a regex pattern.
Generate Python re module code from a regex pattern.
Generate PHP PCRE code (preg_match, preg_replace, preg_split) from a regex.
Generate Java Pattern/Matcher code from a regex.
Generate Go regexp code (RE2) from a regex pattern.
Generate Ruby regex code (.match, .scan, .gsub, .split) from a pattern.
Generate C# System.Text.RegularExpressions code from a regex.
Generate Rust code with the regex crate from a pattern.
Generate Perl regex code (qr//, =~, s///) from a pattern.
Generate Bash, grep, sed, and awk one-liners from a regex pattern.
Generate PowerShell regex code (-match, -replace, [regex]::Matches) from a pattern.
Generate PostgreSQL, MySQL, and SQLite regex queries from a pattern.
Split text using a regex as the delimiter.
Extract capture groups from every match as JSON.
Turn regex capture groups into a downloadable CSV.
Find every match and tally how often each unique value appears.
Delete every regex match from the text.
Discard everything except what your regex matches.
Searchable reference of regex tokens, anchors, quantifiers, and groups.
Every JS regex flag explained with a live before/after example.
Reference for \d \w \s, sets, ranges, and Unicode property classes.
Feature × engine matrix comparing JS, PCRE, Python, Java, .NET, Go, Ruby, Rust.
Validate email addresses against a basic or RFC-style regex.
Validate URLs against a strict http(s) or any-scheme regex.
Validate IPv4 addresses and break them into octets.
Validate IPv6 addresses including compressed :: forms.
Validate EUI-48 MAC addresses with colons or hyphens.
Validate UUIDs (v1–v5) and detect the version.
Validate phone numbers against E.164 or US formats.
Detect card brand and verify the Luhn checksum.
Validate hex colors and preview RGB(A) channels with a swatch.
Validate ISBN-10 or ISBN-13 with format and check-digit verification.
Build a custom email-validation regex from a checkbox form.
Build a URL-matching regex by toggling schemes, hosts, and required parts.
Build an IPv4-matching regex with optional CIDR and strict-octet checks.
Build a regex for common date formats with strict month/day ranges.
Build a regex for 12- or 24-hour time with optional seconds and milliseconds.
Generate a credit-card regex from selected brand checkboxes.
Build a password-policy regex using lookaheads for required character classes.
Build a URL-slug regex with separator, length, and start-character options.
Build a hex color regex supporting any combination of 3/4/6/8-digit forms.
Build a username regex with length, allowed characters, and separator rules.
Convert shell glob patterns to regex.
Best-effort conversion of a regex into a shell glob.
Convert .gitignore rules into regexes and test paths.
Test Apache RewriteRule patterns against a URL.
Test nginx location blocks against request URLs.
Check whether a URL is crawlable by a given user-agent.
Parse log lines with a custom named-group regex.
Parse nginx access logs in combined format.
Parse Apache access logs (CLF and Combined).
Browse a copyable library of common regex patterns.
Quick answers to the questions developers ask most.
Switch context — 11 more toolsets ready to go.