Regex Tester

See Every Match, Instantly

Writing a regular expression usually means a cycle of guess, run, and squint at the output. This tool collapses that loop — matches highlight directly inside your test text as you type either the pattern or the text, with a full breakdown of every match's position and capture groups below, plus one-click presets for the patterns people search for most (email, URL, phone number, and more).

Useful for: developers writing form validation, QA engineers testing input patterns, and data analysts cleaning or extracting text from messy files.

How to Use This Tool

1. 1Type or paste a regular expressionOr start from a common preset like email, URL, or phone number.
2. 2Toggle flags as neededGlobal, ignore-case, multiline, dot-all, unicode, and sticky — each with a tooltip explaining it.
3. 3Paste your test textMatches are highlighted directly in the text as you type either field.
4. 4Check the match tableSee every match's exact position and any capture groups it contains.

Understanding Regex Flags

1. 1g (global) — find every match, not just the firstWithout it, most engines stop after the first match. This tool always searches globally for highlighting, regardless of your flag choice, so you can see every match at a glance.
2. 2i (ignore case) — "Cat" matches "cat"Makes the entire pattern case-insensitive, useful when you don't want to write out every capitalization variant manually.
3. 3m (multiline) — ^ and $ match line starts/endsWithout this flag, ^ and $ only match the very start and end of the whole string, not each line within it.
4. 4s (dot-all) — . also matches newlinesBy default, . matches any character except a newline. This flag makes it match newlines too, useful when a pattern needs to span multiple lines.

Frequently Asked Questions