Regex Validator
Check a regular expression's syntax before you use it in code.
g i m s u v y d
| Property | Value |
|---|
| Test string | Match? | Groups |
|---|
● Your data is processed locally in your browser and is never uploaded to our servers.
How it works
The pattern is compiled by your browser's JavaScript engine: if it compiles, it's valid JavaScript regex syntax, and any error is shown in plain words. The tool lists capturing groups and named groups, and warns about features that don't exist in other flavors (lookbehind in older engines, named groups syntax in PCRE vs. Python, the v flag) and about patterns at risk of catastrophic backtracking, like nested quantifiers (a+)+.