WeVividWeVividCheck the length and check digit of an IMEI to catch typing mistakes.
This checks the number's format with the Luhn formula. It doesn't prove the phone is genuine or not blacklisted — use your country's official CEIR/KYM service for that.
15 digits; the last is a check digit.
The first 8 digits identify the phone model and type approval.
No. Everything is worked out in your browser and nothing you type is sent to a server.