# CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Number Activity: WhatsApp number check API

> Check WhatsApp registration and return last-seen time, days since last online and business account status.

CheckNumber.AI's Free trial plan for the WhatsApp number check API costs $0.00 per 1,000 phones. We check each provider's docs for 6 fields. CheckNumber.AI's docs list 2: Business account, WhatsApp profile.
We haven't run a WhatsApp number check API benchmark yet.
This plan is free. We rank 99 plans for WhatsApp number check APIs by price. Half the plans cost $3.20 or less per 1,000 phones.
[ZelNum's $500 pack](https://datacircle.dev/check-whatsapp-apis/zelnum/500-pack-pay-as-you-go-500-top-up-post-detect/llms.txt) costs the least per 1,000 phones: $0.043. [Wawp's €39 yearly plan](https://datacircle.dev/check-whatsapp-apis/wawp/39-yearly/llms.txt) costs the least for 10,000 phones a month: about $3.66.

- This page: https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-number-activity
- Get it: https://checknumber.ai/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- Request: `POST https://api.checknumber.ai/v1/tasks`, WhatsApp Number Activity
- API key: with the plan, on https://checknumber.ai/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- Its API docs: https://docs.checknumber.ai/whatsapp-activity-checker/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- Sold by: CheckNumber.AI (https://checknumber.ai?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing)
- Checked: 2026-10-28

## In the answer

- Completeness: 33%
- Business account: ✓
- WhatsApp profile: ✓

## Price

- $ per 1,000 phones: $0.00
- Per: result
- Billing: free

## Not found

- $ per 1,000 calls that find nothing: $0.00

## In their words

- Their pitch: Check WhatsApp registration and return last-seen time, days since last online and business account status.

## Data

- Countries: Worldwide
- What it checks: messaging apps
- Keep data: no limit
- Use data: "This license is granted solely for Your internal business purposes" (3.1), "You agree not to (a) license, sublicense, sell, resell, transfer, assign, distribute, or otherwise commercially exploit or make available to any third party the Service in any way, except as expressly permitted by these Terms or an Agreement, (b) modify or make derivative works based upon the Service, (c) reverse engineer, decompile, or disassemble the Service or attempt to gain unauthorized access to the Service or its related systems or networks, or (d) use the Service for any purpose or in any manner that is unlawful (including in violation of the PDPA) or prohibited by these Terms. Furthermore, You agree that any phone numbers or associated data obtained through the Service shall not be used by You or any third party acting on Your behalf to: (i) contact any individual without their prior, express, and informed consent for such contact, in accordance with PDPA requirements, (ii) send unsolicited commercial communications (spam), bulk messages, or any messages in violation of applicable anti-spam laws (including the Singapore Spam Control Act) and the PDPA, (iii) send harassing, abusive, threatening, defamatory, obscene, or otherwise unlawful communications, or (iv) engage in any other practices that violate the privacy or data protection rights of individuals or any applicable laws or regulations, including the PDPA" (3.2)

## Plan

- Pay: $0
- You get: 1,000 results
- Enough for: 1,000 results, once

## Rate limit

- Batch: 1,000,000

## Speed

- Answer: by polling

## The call

- You send: file, task_type "ws_active"
- Method: POST
- Path: /v1/tasks

## About the plan

- Plan: Free trial
- Who can get it: anyone who contacts support

## The 5 fields the plan's answer can hold

phone number, activated, last seen, active days, business account

## CheckNumber.AI's plans (3)

- [CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-number-activity/llms.txt): $0.00 per 1,000, 33% complete
- [CheckNumber.AI, top-up from $20, Pay as you go, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/top-up-from-20-pay-as-you-go-post-v1-tasks-whatsapp-number-activity/llms.txt): $0.15 per 1,000, 33% complete
- [CheckNumber.AI, contact us, Custom plan, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/contact-us-custom-plan-post-v1-tasks-whatsapp-number-activity/llms.txt): 33% complete

## CheckNumber.AI's calls for this API (4)

- `POST /v1/tasks`, WhatsApp Advanced: [CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Advanced](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-advanced/llms.txt)
- `POST /v1/tasks`, WhatsApp Age & Gender Checker: [CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Age & Gender Checker](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-age-gender-checker/llms.txt)
- `POST /v1/tasks`, WhatsApp Checker: [CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Checker](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-checker/llms.txt)
- `POST /v1/tasks`, WhatsApp Number Activity: [CheckNumber.AI, free trial, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-number-activity/llms.txt)

## CheckNumber.AI's APIs (3)

- [CheckNumber.AI Email verification API pricing, 3 plans](https://datacircle.dev/validate-email-apis/checknumber-ai/free/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Band Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-band-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/phone](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-phone/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, iMessage Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-imessage-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Line Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-line-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Line Profile Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-line-profile-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, MAX Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-max-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, MAX Full Profile Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-max-full-profile-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Messenger Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-messenger-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Number Activity](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-number-activity/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Number Validation](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-number-validation/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Phone Carrier Bulk Lookup](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-phone-carrier-bulk-lookup/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, RCS Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-rcs-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Signal Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-signal-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Telegram Age & Gender Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-telegram-age-gender-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Telegram Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-telegram-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Telegram Number Activity](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-telegram-number-activity/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, US Carrier Advanced](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-us-carrier-advanced/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Viber Age & Gender Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-viber-age-gender-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Viber Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-viber-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Viber Number Activity](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-viber-number-activity/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Zalo Age & Gender Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-zalo-age-gender-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Zalo Checker](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-zalo-checker/llms.txt)
- [CheckNumber.AI Phone validation API pricing, 3 plans, POST /v1/tasks, Zalo Number Activity](https://datacircle.dev/validate-phone-apis/checknumber-ai/free-trial-post-v1-tasks-zalo-number-activity/llms.txt)
- [CheckNumber.AI WhatsApp number check API pricing, 3 plans, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/free-trial-post-v1-tasks-whatsapp-number-activity/llms.txt)

## CheckNumber.AI: WhatsApp number check API alternatives

[CheckNumber.AI alternatives: other WhatsApp number check API providers by price](https://datacircle.dev/checknumber-ai-alternatives.txt)

We list CheckNumber.AI's cheapest paid plan first. Next we list other providers' plans closest to CheckNumber.AI in price per 1,000 phones.

- [CheckNumber.AI, top-up from $20, Pay as you go, POST /v1/tasks, WhatsApp Number Activity](https://datacircle.dev/check-whatsapp-apis/checknumber-ai/top-up-from-20-pay-as-you-go-post-v1-tasks-whatsapp-number-activity/llms.txt): $0.15 per 1,000, 33% complete
- [ZelNum, $100 pack, Pay as you go, $100 top-up, POST /detect/file](https://datacircle.dev/check-whatsapp-apis/zelnum/100-pack-pay-as-you-go-100-top-up-post-detect-file/llms.txt): $0.048 per 1,000, 0% complete
- [WasenderAPI, $45 monthly](https://datacircle.dev/check-whatsapp-apis/wasenderapi/45-monthly/llms.txt): $0.15 per 1,000, 17% complete, live
- [2Chat, $100 pack, Extra requests package, GET /open/whatsapp/check-number/{your-number}/{number-to-check}, Check Number](https://datacircle.dev/check-whatsapp-apis/2chat/100-pack-extra-requests-package-get-open-whatsapp-check-number-your-number-number-to-check-check-number/llms.txt): $0.20 per 1,000, 83% complete, live
- [NumDetect, $499.90 pack, Scale, POST /api/v1/bulk-jobs, Bulk check, WhatsApp](https://datacircle.dev/check-whatsapp-apis/numdetect/499-90-pack-scale-post-api-v1-bulk-jobs-bulk-check-whatsapp/llms.txt): $0.208 per 1,000, 33% complete, live

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-10-28.

- https://checknumber.ai/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- https://checknumber.ai/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- https://checknumber.ai/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- https://docs.checknumber.ai?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing
- https://docs.checknumber.ai/whatsapp-activity-checker/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=whatsapp-number-check-api-pricing