Our take: Shows matches and a plain explanation as soon as you type a pattern. No requests went to a server during testing, and there are hardly any ads.
- ✓ No sign-up — tested
- ✓ 0 server requests while testing — tested
- PCRE, JavaScript, Python and more
- ! Save/share uploads your regex
- ? China access — not tested yet
Our test
Tested 28 Sep 2026 · Chrome desktop · regex \d{3}-\d{4} on “call 555-1234 or 555-9876”
Matches2 (correct)
ExplanationEach token explained
Server requests0
How we checked privacy: While we entered the pattern and test string, there were zero network requests. If you Save or share, the regex and text are stored on its server and may be reachable by link.
Data sheet
Every row shows how we know it
| Free limit | Free Tested |
|---|---|
| Sign-up | Not required Tested |
| Result | Both matches shown correctly Tested |
| Processing | Testing runs in your browser Tested |
| Save/share | Stored on its server when saved Official |
| Access from China | — Not tested |
When to use it
Building a pattern to pull what you need out of logs or data, and understanding how it works.
Before you use it
Saving or sharing stores the regex and sample text on its server — don’t paste real customer data.
How to use it
- Open regex101.com (no sign-up).
- Pick a flavor on the left and enter your regex and test string.
- Refine the pattern using the explanation and matches on the right.
Alternatives
- JSON Formatter — format JSONOn-device
- JSFiddle — run code snippetsUploads to server
Last verified 28 Sep 2026 · Found something outdated? Tell us. · Official site