Regex Tester

Test your patterns.

Live match highlighting.

Test string
Matches
No upload
Works offline
No idea what's in your data

Need regex tools in your workflow? The offline bundle includes CLI regex utilities. $99 once.

Get Bundle →
// How it works

Three steps. Zero uploads.

01
Type
Enter your regex pattern and test string. Toggle flags as needed. It stays on your device.
02
Match
fwip highlights matches live as you type. Capture groups are shown with indices and names.
03
Copy
Copy matches or the pattern. Nothing was ever uploaded.
// Why this is different

Your patterns stay in your browser.

Some online regex testers send your patterns and test data to a server. fwip uses your browser's native RegExp engine with zero network requests.

fwip works differently. The tester runs entirely in your browser. Your data is read from your device, processed on your CPU, and the result is saved back to your device. No server is involved. We literally cannot see your file.

No server processing

Everything runs on your device using WebAssembly. Your file never touches a network.

No account required

Drop a file. Get a result. No sign-up, no email, no password.

No subscription

Free in the browser. $99 once for the offline bundle. That's it. Forever.

Works offline

The desktop version works with no internet connection at all.

// Questions

Frequently asked.

How do I test regex patterns without uploading?▾
Type your regex and test string into fwip. Matches are highlighted live as you type. Everything runs in your browser using the native RegExp engine.
Does fwip support regex flags?▾
Yes. Toggle global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u) flags. All flags from the JavaScript RegExp engine are supported.
Can I see capture groups?▾
Yes. fwip shows all match groups with their indices. Named capture groups are displayed with their group names.
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