How to use the Phone Number Formatter
Format an entire contact list in seconds — one number per line.
1
Paste your phone numbers
Paste your raw phone numbers into the input area, one per line. They can be in any format — with dashes, dots, parentheses, country codes, or no formatting at all.
2
Configure format and region
Choose your output format (E.164, International, or National) and set the default region for numbers that do not include a country code. Optionally enable "Deduplicate" and "Hide invalid" toggles.
3
Copy valid results
Invalid entries are marked inline so you can see exactly which numbers failed. Click "Copy valid" to copy only the successfully formatted numbers to your clipboard.
When to use this tool
Use the Phone Number Formatter any time you have a batch of phone numbers in inconsistent formats that need to be normalized.
- →Standardizing phone numbers before importing a contact list into a CRM or marketing platform
- →Converting national-format numbers to E.164 for use with Twilio, Vonage, or another SMS API
- →Validating phone numbers exported from a form submission or spreadsheet to catch invalid entries
- →Deduplicating a contact list that has the same numbers stored in different formats
- →Preparing a clean phone list for a dialier system that requires a specific format
- →Checking which numbers in a list belong to a specific country region before a calling campaign
Frequently asked questions
Q:What is E.164 format and why should I use it?
E.164 is the international standard format for phone numbers, defined by the ITU. It consists of a + sign followed by the country code and subscriber number with no spaces or punctuation (e.g., +15551234567). It is the required format for most telephony APIs including Twilio, AWS SNS, and WhatsApp Business.
Q:Which countries and dialing codes does the tool support?
The formatter uses the libphonenumber library (the same library used by Google and Android) which supports phone number parsing and formatting for every country and territory with an assigned ITU dialing code — over 240 regions in total.
Q:What happens to numbers that fail validation?
Invalid numbers are displayed inline with an "(Invalid)" marker so you can identify them at a glance. They are kept in the output for review but excluded when you click "Copy valid", so your clipboard only receives correctly formatted numbers.
Q:How does the default region setting affect the output?
The default region is used to interpret numbers that do not include a country code prefix. For example, if your region is set to US, the number "5551234567" will be interpreted as a US number and formatted as +15551234567 in E.164. If your numbers already include a + and country code, the region setting has no effect.
Q:Can the tool detect and remove duplicate phone numbers?
Yes. Enable the "Deduplicate" toggle to remove lines where the formatted output is identical to a previously seen number. Deduplication is performed on the normalized formatted value, so numbers that look different in the input (e.g., "(555) 123-4567" and "5551234567") but resolve to the same E.164 number will be correctly identified as duplicates.
Q:Is there a limit to how many phone numbers I can format at once?
There is no hard limit. All processing runs in your browser using JavaScript, so practical throughput depends on your device. In typical use, lists of tens of thousands of numbers format in well under a second. For very large datasets (millions of numbers), a server-side script using libphonenumber would be more appropriate.