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WhatsApp API · Bulk checks · Webhook-ready

WhatsApp Number Check API — 10K Numbers/Minute

Verify WhatsApp availability, account age, and list quality at API speed without sending messages to the checked numbers.

bulkchecker.io gives developer teams a verification-first API for signup flows, CRM enrichment, campaign prep, and high-volume WhatsApp list cleaning.

Throughput
10K/min
Privacy
No messages sent
Accuracy
99%
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Capabilities

API Capabilities

Use one API for real-time checks, bulk jobs, account maturity signals, and async callbacks.

Single number check

Check one phone number for WhatsApp registration, active status, and privacy-safe availability.

Bulk check (up to 10K per request)

Submit a batch request and receive a job ID for high-volume list processing.

Account age detection

Add age bands and active-day signals for lead scoring, spam review, and fraud prevention.

Async with webhook

Run large jobs asynchronously and receive completion callbacks when results are ready.

Developer quick start

Quick Start

Create a key, call the endpoint, and store the response fields your product needs.

1

Get API key

Create a project in bulkchecker.io, generate a server-side key, and configure usage limits.

2

First curl call

curl -X POST https://api.bulkchecker.io/v1/whatsapp/check \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "phone": "+14155550198",
    "include_age": true
  }'
3

JSON response example

{
  "id": "wch_7f4a91",
  "phone": "+14155550198",
  "whatsapp_registered": true,
  "active_status": "active",
  "message_sent": false,
  "account_age": {
    "segment": "mature",
    "active_days": 1126
  },
  "confidence": 0.99,
  "checked_at": "2026-05-09T10:30:00Z"
}
Reference

Endpoints

Use synchronous checks for single numbers and async jobs for large WhatsApp verification batches.

Endpoint
Mode
Best for
Response

POST /v1/whatsapp/check

Sync
Single number checks
Immediate JSON

POST /v1/whatsapp/bulk

Async
Up to 10K per request
Job ID

GET /v1/whatsapp/result/{job_id}

Polling
Download completed jobs
Results JSON
SDKs

SDKs

Use a native client or call the REST API directly from your backend service.

Python
Node
Ruby
PHP
Go
.NET
Usage-based

Pricing

Start with API credits for testing, then move to volume tiers for campaign and CRM workloads.

Tier
Monthly volume
Rate
Included
Developer
10K checks
$1 / 10K
API access
Growth
1M checks
Volume rate
Webhook jobs
Enterprise
10M+ checks
Custom
SLA and support
Developer workflows

Use Cases for Developers

Build WhatsApp availability checks into the points where bad numbers are most expensive.

Signup risk screening

Flag new or unregistered WhatsApp numbers before trial abuse, spam, or risky onboarding.

Campaign pre-validation

Clean large campaign lists before upload to protect spend, deliverability, and sender reputation.

CRM enrichment

Add WhatsApp status and account age fields to lead records, customer profiles, and routing rules.

Comparison

Compare with WA Business API

The official messaging API and a verification API solve different developer problems.

WA Business API

  • Built for approved business messaging and conversations.
  • Requires business setup, templates, and platform-specific sending rules.
  • Best when you need to send messages after consent and approval.

bulkchecker.io WhatsApp API

  • Built for verification, list hygiene, and risk scoring.
  • Checks WhatsApp availability without sending a visible message.
  • Best before campaigns, CRM imports, signup review, and fraud workflows.
FAQ

WhatsApp Number Check API FAQ

Answers about limits, privacy, business account requirements, and reliability.

API rate limits?
Default plans support up to 10K numbers per minute, with higher limits available for enterprise workloads.
Privacy & data handling?
The API is designed for list hygiene and verification workflows, with no visible WhatsApp message sent to the checked number.
Can I check via API without WA Business account?
Yes. This API is for verification and enrichment, not for sending WhatsApp messages from your business account.
SLA?
Enterprise plans can include uptime commitments, support response targets, and dedicated throughput planning.
Is this the WhatsApp checker API and WhatsApp number lookup API?
Yes. The same endpoint is the WhatsApp checker API and the WhatsApp number lookup API. Send single numbers via REST for real-time checks, or batch up to 10,000 numbers per call for bulk verification.