Frequently Asked Questions

Yes. There is no credit card, no trial that converts to a paid plan, no daily credit system, and no hidden per-check fee. The service is funded by simple banner ads on the result page, which lets us keep unlimited bulk checks free for every visitor.

Each batch supports up to one thousand numbers. You can run as many batches as you like, back to back, with no daily cap. Most users paste a CSV column or drop a CSV file and the validator streams results in under a minute.

No. There is no login screen, no email capture, and no cookie wall. Open the site, paste your numbers, get results. The anonymity is intentional so marketing teams and researchers can validate lists without leaving a billing trail.

The check is safe for you because it happens server-side using isolated pool sessions. Your own WhatsApp account is never involved and never contacted. WhatsApp does not notify the number owner that someone looked them up; the validation uses a registration lookup, not a message send.

Any CSV with one phone number per row works. Numbers can live in the first column or be detected automatically. We recommend E.164 format (for example +14155551234) because it removes ambiguity about country codes. Extra columns such as name or email are ignored, not stored.

Yes. The validator supports every country code WhatsApp serves. Numbers should include the plus sign and country code for best accuracy. The result screen shows a detected country label next to each number so you can spot misformatted entries at a glance.

BulkNumberChecker only validates whether a number is registered on WhatsApp. It does not send messages and is not a blast tool. Many marketing teams use the output CSV to clean their list before importing it into a compliant broadcast platform such as the WhatsApp Business API.

Accuracy tracks the WhatsApp registration endpoint, which is the same source most paid tools use. In practice, that means near-perfect results for recently-registered numbers. The one edge case is accounts deactivated in the last few hours; those occasionally appear active for a short window before propagation catches up.

Valid means the phone number is syntactically correct and routable by its carrier. Active means that number has a WhatsApp account attached to it. A number can be valid but inactive (no WhatsApp), or invalid entirely (wrong length, disconnected line). Our result screen uses the active status because that is what matters for WhatsApp outreach.

Numbers live in a short-lived result cache tied to your result URL and expire automatically after the TTL. We do not build profiles, we do not resell lists, and we do not retain the underlying phone numbers once the cache expires. Our privacy page has the full retention policy.

A public API is on the roadmap and will ship without a credit-based pricing model. Until then, the web app handles batches of one thousand numbers with a progress indicator, and the CSV export is easy to pipe into any downstream script.

Paid tools charge per thousand numbers, require signup, and often tie validation to your personal WhatsApp account (in the case of Chrome extensions). BulkNumberChecker is free, anonymous, server-side, and unlimited. For a side by side breakdown, see our comparison page.

Every country WhatsApp supports is supported here, including the United States, United Kingdom, Brazil, India, Indonesia, Nigeria, Mexico, Germany, Spain, and all of the European Union. The detection logic resolves the country by the leading digits of the E.164 number.