Product slug routing
Choose the WhatsApp product slug from the app docs and submit it through the shared detection endpoint.
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 an API for campaign prep, CRM hygiene, community list cleaning, and high-volume WhatsApp verification jobs.
Throughput
10K/min
Privacy
No messages sent
Accuracy
99%
Request pipeline
Validate
Queue
Callback
Throughput
10K/min
ModeREST
JobsAsync
Capabilities
API Capabilities
Use the unified BulkChecker API for WhatsApp product slugs, bulk jobs, account signals, and async result downloads.
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 campaign filtering, account quality review, and community list cleanup.
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.
Get API key
Create a key in the BulkChecker app API Center and keep it on your server.
First curl call
curl -X POST "https://api.bulkchecker.io/api/v1/detect" \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"product": "wsValid",
"country": "US",
"phones": ["+14155550198", "+442071838750"]
}'JSON response example
{
"mode": "async",
"task_id": "xKj9aP3qLm7v",
"message": "Task queued.",
"summary": {
"total": 5000,
"cost_deducted": 0.500000
}
}Reference
Endpoints
Use the shared API endpoints below for WhatsApp jobs. The product field controls whether you run number, activity, or profile-style checks.
Endpoint
Mode
Best for
Response
POST /api/v1/detect
Async
Phone array jobs
Task ID
POST /api/v1/detect/file
Async
CSV/TXT uploads
Task ID
GET /api/v1/tasks/{task_id}/result
Polling
Completed jobs
Download URL
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 a free API test, 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
Priority support
Developer workflows
Use Cases for Developers
Build WhatsApp availability checks into the points where bad numbers are most expensive.
Campaign list pre-check
Spot unregistered or low-quality WhatsApp numbers before campaign upload, outreach, or community list import.
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 bulk list segmentation.
- Checks WhatsApp availability without sending a visible message.
- Best before campaigns, CRM imports, community outreach, and airdrop list cleanup.
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.
Support options?
Higher-volume plans can include 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 spot checks, or batch up to 10,000 numbers per call for bulk verification.
WhatsApp verification cluster
Related WhatsApp verification pages
Messaging App CheckerPillar hub for WhatsApp, Telegram, Viber, LINE, Zalo, Signal, and related app checks.WhatsApp Number CheckerVerify WhatsApp registration in bulk without sending messages.Bulk WhatsApp CheckerUpload WhatsApp contact files and export registered, unavailable, and review segments.WhatsApp Age & Gender CheckerExport WhatsApp profile attribute signals from bulk phone lists.WhatsApp Account Age CheckerUse account age signals for fraud, trust, and campaign filtering.Check WhatsApp OnlineRun a quick free lookup before using the bulk workflow.Best WhatsApp CheckersCompare tools for WhatsApp validation, enrichment, and list cleaning.
AI answer engines
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