Phone Number Formatter (E.164)
Paste a messy phone number from a contact list, a scrape, or a form. This cleans it into the canonical E.164 form, detects the country from the calling code, splits the country code from the national number, and checks the length. Everything runs in your browser, with no API and no network call. This is format and length validation only, not a check that the line is live or assigned.
What E.164 is, and why length validation is not the whole story
The E.164 format
E.164 is the international standard from the ITU-T for how a phone number is written so that any network in the world can route it. The canonical form is a leading plus sign, then the country calling code, then the national number, with no spaces or punctuation. The whole thing is at most 15 digits after the plus. For example +14155552671 is the United States calling code 1 followed by the 10-digit national number 4155552671. The plus is a placeholder for whatever international dialing prefix a caller's own network uses (often 00, or 011 in North America), so storing numbers in E.164 keeps them portable across countries.
Calling codes and the longest-prefix rule
Calling codes are one to three digits and they are assigned so that no code is a prefix of another, which means a number can be matched unambiguously. Some codes are short (1 for North America, 7 for Russia and Kazakhstan), while others are three digits (351 for Portugal, 998 for Uzbekistan). This tool reads the digits from the left and takes the longest code that matches the table, then treats the rest as the national number.
+1 covers all of North America
The +1 code is the North American Numbering Plan (NANP), shared by the United States, Canada, and around twenty Caribbean territories. They are told apart by the three-digit area code at the start of the national number, not by the country code. Because that mapping shifts over time and is not part of E.164 itself, this tool reports +1 as North America rather than guessing a single country. A full carrier or region lookup is the reliable way to pin down a specific +1 number.
What length validation can and cannot tell you
Each country has an expected national-number length (or a small range of lengths). Comparing the cleaned number against that range catches the common mistakes in scraped data: a digit dropped, an extra digit pasted in, a trunk 0 left on the front, or the wrong country assumed. That is genuinely useful for cleaning a list. What it cannot do is confirm that a number is live, assigned to anyone, or reachable. A number can be perfectly valid in length and still be unassigned, disconnected, or ported to a different carrier. For carrier, line type (mobile, landline, VoIP), and live-line signals you need a network lookup such as Twilio Lookup, which the paid Phone Lookup on this site uses. Treat a passing length check as "well-formed", not as "real". The length data here is derived from ITU-T E.164 national numbering plans and is a practical approximation, not a guarantee for every special or short-code range.