Live regex match highlighting against your own text, with a cheat-sheet of common patterns alongside
Pattern
//gi
Test string
Replacement preview
Save this pattern
Live match highlighting
No matches
Enter a pattern and some test text to see live highlighting here.
Result after replacement
Matches
No matches yet.
Regex compiling, matching and highlighting all happen inside this app using the browser engine's own JS RegExp - nothing is ever sent anywhere. Very broad patterns against very long text may be slow to highlight; the match table is capped per the "Max matches shown" setting.
Defaults
Applied the next time you open the app. Letters: g, i, m, s, u, y.
Caps both the highlight canvas and the match table, to keep very broad patterns responsive on long text.
Backup
Saved patterns live only in this app's local storage on this device. Export a backup, or import one you exported earlier.
Data
Metre2 Regex Tester never sends your pattern, test text or saved patterns off this device. Everything happens locally.
Rename pattern
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Import saved patterns
Paste JSON exported from this app (or another Regex Tester install). Imported patterns are added alongside your existing ones.