Phone Number Validation & Formatting API

You can send numbers in international E.164 form (e.g. +14155552671), in which case the country is detected automatically, or in a local format (e.g. (415) 555-2671). For local formats, supply a country hint using the ISO 3166-1 alpha-2 code (US, GB, TR, etc.) so the parser knows which numbering plan to apply. Both GET requests with query parameters and POST requests with a JSON body are supported.

Genuinely unparseable input returns a clean negative result with HTTP 200: { "input": "not-a-number", "valid": false, "possible": false }. The API does not throw errors for bad numbers, so you can branch on the valid and possible flags directly. A 400 status is reserved strictly for a missing number parameter or a malformed JSON body.

The possible flag checks only that the number has a plausible length and shape for its region, while the valid flag confirms the number fully conforms to that region's numbering plan. These independent flags let you choose your strictness: accept possible numbers during fast onboarding to reduce friction, then enforce full validity before billing or messaging customers.

Yes. Every successful response includes a type field with the detected line type (such as MOBILE, FIXED_LINE, or FIXED_LINE_OR_MOBILE) plus convenience booleans is_mobile and is_fixed_line. This is ideal for deciding whether to send an SMS, place a voice call, or flag a suspicious signup. Note that for some numbering plans the type may be FIXED_LINE_OR_MOBILE when the plan does not distinguish between the two.

The API is powered by Google's libphonenumber metadata, so it covers over 240 countries and territories — the same numbering-plan data used in production by Android and many major platforms. Coverage includes full validation, formatting, and line-type detection for each supported region's numbering plan.

Pass your API key as a query parameter, ?apikey=YOUR_KEY, or send it in an X-Api-Key header. All plans share the same full feature set and global edge latency.

The API is stateless and runs on a global edge network, delivering typical parse-and-format response times under 50ms. Because validation is performed locally against bundled libphonenumber metadata rather than calling out to external carriers, there is no network round-trip to a third party, keeping latency consistently low for production form validation and high-volume batch processing alike.