Free tool
Free WhatsApp number checker & list cleaner
Paste your contact list and get it back clean: international format fixed, duplicates removed, invalid rows flagged. Everything runs in your browser — your list is never uploaded.
Results will appear here as you paste numbers.
How to verify a single number is on WhatsApp
WhatsApp has no public registration-check API, so the reliable test is a wa.me link: open https://wa.me/<number> in a browser. If the number is on WhatsApp, a chat opens; if not, WhatsApp shows “phone number shared via url is invalid”. Use our link generator to build the link in one click.
Why cleaning your list matters before a campaign
- Fewer failed sends. Missing country codes and leftover leading zeros are the top causes of delivery failures.
- No double messages. Duplicates mean the same person gets your message twice — a fast way to get reported.
- Protect your number. Sending to many invalid or unregistered numbers in a row is a signal WhatsApp's anti-spam systems watch for.
- Accurate stats. A clean list makes your delivery and reply rates meaningful.
Clean list? Send it as a campaign
Import your cleaned numbers into WhatsApp Sender Tool and send personalized messages with name placeholders, AI-written variants, voice notes, randomized delays and daily limits that keep your number safe. No account — buy a license code and paste it into the extension.
WhatsApp number checker FAQ
Does this tool check if a number is actually on WhatsApp?
It validates the format and lets you open a chat to confirm. WhatsApp does not offer a public "is this number registered" API, so any tool claiming instant bulk registration checks is guessing. The reliable way: open the wa.me link — if the number is not on WhatsApp, WhatsApp tells you.
Is my contact list uploaded anywhere?
No. All cleaning and validation happens in your browser. Nothing is sent to our servers — you can even disconnect from the internet and the tool keeps working.
What format does WhatsApp need?
Full international format, digits only: country code + number, no +, no 00, no spaces, dashes or brackets. Example: 14155550134. The cleaner below converts your numbers to this format automatically.
Why do my messages fail on some numbers?
The most common causes are a missing country code, a leading zero kept after the country code, landline numbers, and numbers no longer registered on WhatsApp. Cleaning the list first removes most failures.
How many numbers can I paste at once?
The tool handles thousands of rows comfortably since everything runs locally. For very large lists (50,000+), clean the file in batches.
Can I send to the cleaned list right away?
Yes — copy the clean list into a CSV and import it into WhatsApp Sender Tool, which sends personalized messages with safe delays and daily limits. Remember to message only people who agreed to hear from you.
Also useful: Excel / CSV to WhatsApp · Message formatter · Pricing