Phone Number Checker
Validate any phone number: country, line type and the correct international format.
This checker is built on libphonenumber — the open-source library by Google that powers number validation in Android and countless apps — running entirely in your browser. It checks the number against the official numbering plan of its country: the right length, the right prefixes, and ranges that are actually allocated.
How to use
- Type or paste the number in international format — a plus sign, the country code, then the number (for example +44 20 7946 0958).
- Press Check (or hit Enter).
- Read the verdict: validity, country, line type from the numbering plan, and the number rewritten in international, national and E.164 formats.
About this tool
The line type is read from the number block: some ranges are reserved for mobiles, some for landlines, some for toll-free or premium services, and in countries that allocate dedicated VoIP ranges (such as the UK’s 056 block) the checker can say "VoIP" with confidence.
Where the plan itself cannot tell — most famously in North America, where +1 VoIP and landline numbers share one pool and can be ported between carriers — the tool says so instead of guessing. Treat any service that claims to identify every US VoIP number from the digits alone with suspicion: accurate answers there require a live carrier database lookup, which is a different (paid) kind of service.
Frequently asked questions
Can this tell if a US number is VoIP or a landline?
Not reliably — and neither can any tool that only looks at the number. US VoIP services get numbers from the same pool as landlines, and numbers port between carriers. This checker reports the numbering-plan category (often "fixed line or mobile" for +1). A definitive answer needs a carrier lookup service.
What is E.164 format?
The international standard format for phone numbers: a plus sign, country code and subscriber number with no spaces or punctuation — for example +442079460958. Databases, APIs and messaging platforms expect numbers in E.164.
Is the number I check uploaded or stored?
No. The library and all checks run in your browser; the number never leaves your device.
Why does it say "plausible but not confirmed valid"?
The number has the right shape for its country, but its specific block is not in the allocated ranges the library knows — common for brand-new ranges, internal test numbers and small typos that keep the right length.
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