Phone Number Formatter & Validator
Enter a phone number to check if it's valid and see its E.164, national, and international formats — no server, no sign-up.
About this tool
The Phone Number Formatter & Validator parses any international phone number and tells you whether it's valid, then renders it in every standard format.
Enter a number in international form (with a + and country code, e.g.
+1 415 555 2671) and it works on its own. For a number written the local way —
without a + — add the two-letter region code (an ISO-3166 alpha-2 code such
as US, GB, or DE) so it knows which country to interpret it for.
For each number you get:
- Valid — whether the number is a real, dialable number for its region.
- E.164 — the canonical international form (
+14155552671), ideal for storing in a database or passing to an SMS/voice API. - National — how you'd write it locally (
(415) 555-2671). - International — the spaced international form (
+1 415-555-2671). - Country/region — the country the number belongs to.
- Type — the line type (mobile, fixed line, toll-free, VoIP, …) when the metadata can derive it.
Validation and formatting use Google's libphonenumber metadata, bundled into the tool — everything runs in your browser via WebAssembly, so the number you type is never sent to a server.
FAQ
Why isn't my number recognized?
If the number has no + country prefix, the tool has no way to know which
country's dialing plan to apply — add the two-letter region code (US, GB,
DE, …) and it will be interpreted as a local number for that country. Numbers
written in full international form (+44 20 7946 0958) never need a region.
Does "valid" mean the number is actually in service?
No. Valid means the number matches a real, dialable pattern for its region according to libphonenumber's metadata — right length, real prefix, plausible line type. Whether it's currently assigned to a subscriber can only be known by a carrier lookup, which this tool deliberately doesn't do (nothing is sent anywhere).
Which format should I store in my database?
E.164 — the compact canonical form like +14155552671. It's unambiguous,
sorts consistently, and is exactly what SMS and voice APIs (Twilio and friends)
expect. Use the national/international renderings only for display.
Why is the line type sometimes missing or vague?
The type (mobile, fixed line, toll-free, VoIP, …) is derived from number-range metadata, and some countries don't partition ranges cleanly — in the US, for example, mobile and fixed-line numbers share ranges, so a definite answer isn't always possible.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool phone-format "+1 415 555 2671"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/phone-format/?number=%2B1%20415%20555%202671®ion=USMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.