Free-to-use tool
Bulk WhatsApp number formatter (E.164)
Paste a list, one number per line. The tool normalizes Brazilian numbers (area code, ninth digit, country code 55), removes duplicates, flags the reason for each error and exports a CSV. Everything runs in your browser: the list is not sent anywhere.
Paste a list to start.
How to use it
- 1
Paste the phone numbers in the box, one per line, however they are: with brackets, dashes, spaces or +55.
- 2
Read the table: each line shows the E.164 result and its status (valid, fixed, duplicate or error with the reason).
- 3
Copy only the valid numbers or download the CSV with every line and its status.
- 4
Use the clean list in your import or in the API. To know whether each number really has WhatsApp, use the check endpoint afterwards.
What the tool validates and what it does not
For Brazilian numbers it checks the area code (against Brazil's list of areas), the length (13 digits for a mobile with the 55, 12 for a landline) and adds the ninth digit when an old mobile number has 8 digits starting with 6 to 9. A leading zero before the area code is removed.
Numbers that start with + and another country code are flagged as international: the tool only checks that the length fits the E.164 standard (8 to 15 digits) and does not apply each country's rules. No format check tells you whether the number exists or has WhatsApp. Only the API check confirms that, with check number.
Format rules: the E.164 standard (ITU-T) and the Brazilian numbering plan (area codes and ninth digit). Runs 100% in your browser, without sending the list to a server.
Frequently asked questions
Are my numbers sent to a server?
No. Processing happens in your browser and the list does not leave your computer.
How many numbers can I paste?
Thousands of lines work in a current browser. For very large lists, split them into parts.
Why was a valid number flagged as an error?
The table shows the reason: nonexistent area code, number too short or too long, or a 9-digit mobile that does not start with 9. Fix it and paste again.
Does the tool confirm the number has WhatsApp?
No. It only checks the format. Confirmation comes from the API's check endpoint, which queries WhatsApp.
What is E.164?
It is the international numbering standard: plus sign, country code and number, at most 15 digits. Example: +5511956604165.
See also
From the tool to real sending
This tool is free and runs in your browser. To send and receive real messages through the API, the plan is R$15 per active number per month, prepaid with no lock-in. See how it fits your type of business and the tools you already use.
See pricingFor your business
Connect with
Clean list, now send
Import the list into ZapZap's API and send with automatic delay and typing. R$15 per active number per month, no per-message fee.