WhatsApp Number Checker — is this number on WhatsApp?
Paste a phone number in international format and find out whether a WhatsApp account is registered against it. The check runs through a real linked WhatsApp session on our side, which is the only way anyone can answer the question honestly - there is no public directory to look it up in. Because a real session is doing the asking, the tool is rate-limited for anonymous visitors, and heavier use belongs on an API key where the volume is metered and paced properly. The most common reason a number comes back as not registered is a formatting mistake rather than a missing account: a leading zero from the national format, a country code typed twice, or spaces and dashes left in from a spreadsheet. Fix the format first, then trust the answer. A positive result tells you an account exists; it does not tell you the person wants to hear from you, and treating a validated list as a mailing list is the fastest route to a reported number.
How it works
What happens when you press the button is worth knowing, because it explains both the limits and the honesty of the result. Your browser sends the number to a small proxy that holds the token of a dedicated Wapito channel; that channel asks the WhatsApp network whether the number resolves to an account, exactly as your phone does when you add a contact and it appears in the chat list with a profile picture. The proxy returns a yes or a no and forgets the number. It never touches your own channels, never needs you to be signed in, and cannot tell you anything the network would not tell any WhatsApp user who typed the same digits. That is also why the answer is trustworthy: it is not a guess from a carrier database or a scraped list, it is the network itself responding.
The format the checker expects is the international one: the country code, then the subscriber number, with nothing else. Spaces, brackets, dots and dashes are stripped for you, a leading plus sign is fine, and a double-zero prefix is understood as the international dial-out. What cannot be repaired automatically is a trunk prefix, the zero most countries put in front of a local number. The network does not know it is a trunk prefix; it sees a longer number that belongs to nobody, or worse, to somebody else. Drop it, put the country code in front, and check again. If you are cleaning a spreadsheet, do that transformation on the whole column before you start pasting rows into this page, because the mistake is systematic and so is the fix.
When you have more than a handful of numbers, the API is the right tool and the reason is not just the daily cap. Checking a list at speed is the single most automation-shaped thing a WhatsApp account can do, and it is watched accordingly: a fresh number that resolves a thousand contacts in a minute looks like exactly what it is. Behind an API key the same check runs through your own channel with a plan quota, a per-channel pace and a warm-up ladder for young numbers, and the result comes back as structured JSON you can write straight into a column. The endpoint linked below takes one number and returns whether it exists; the batch endpoint on the same feature page takes a list. Use the free tool to settle an argument about one record, and the API for everything that has a loop around it.
Do it with the API
This tool is the browser-side version of one API call.
Frequently asked questions
How many numbers can I check here?
A handful per day per visitor, which is enough to sanity-check a format or investigate one bad record. Bulk checking runs through the API with a plan quota behind it, because checking a list at speed is the most ban-sensitive thing an unofficial WhatsApp API does and it needs pacing rather than a bigger button.
Do you store the numbers I check?
The check is proxied so the tool can be rate-limited, and nothing is kept as a contact record or used for marketing. If you would rather nothing left your machine at all, the same check is one API call from your own backend with your own token, and the page shows exactly that call.
Why does a number I know is on WhatsApp say no?
Nine times out of ten the format is wrong. WhatsApp addresses numbers in full international form with no leading zero and no punctuation, so a national-format number is a genuinely different number as far as the network is concerned. Strip the trunk prefix, add the country code, and check again.
Related
Try it on your own number
Create a channel, link a WhatsApp number by QR or pairing code, and call the API in a couple of minutes. The Sandbox plan is free and needs no card.