Enter WhatsApp Number
Enter a phone number in E.164 format or select a country code.
Make sure to include the country code, without spaces or special characters.
Your data is secure and never shared with third parties.
Complete captcha and check a number.
Zefir validates millions of numbers in minutes — 99%+ accuracy, TCPA-compliant, run entirely for you.
For entire lists, Zefir runs bulk verification at scale — millions of numbers checked in minutes, before you spend a dollar sending.
Upload Contacts
Upload CSV, Excel, or sync segments directly from Shopify
Verify Numbers
Check WhatsApp availability instantly.
Review Results
Active, inactive, and invalid numbers, segmented and ready to use.
Launch Campaigns
Lower send costs, zero wasted messages, protected sender rating.
To find out if a phone number is registered on WhatsApp, follow these steps:
Enter the phone number you want to check, including the full international format: country code and area code. For example, if the country code is +1 and the local number is (415) 555-0132, enter it as 14155550132
Click 'Check Number.' The result appears instantly, showing whether the number has an active WhatsApp account.
WhatsApp numbers lookup
1
Enter phone number
2
Click to check
3
View result
Active / Not Active
WhatsApp Direct Messaging
1
Verify Number
2
Open Chat
3
Send Message
No Contact Save Required
To send a message on WhatsApp without saving the phone number to your contact list:
Check if the number is linked to WhatsApp using the online WhatsApp Checker by Zefir on the top of this page
If the number is on WhatsApp, you’ll be able to instantly open a chat in the messenger app and send a message by clicking the “Send a message” button