# WSAPI, free trial, POST /users/check: Phone validation API

> Check multiple phone numbers at once to see if they are registered on WhatsApp.

WSAPI's Free Trial plan for the phone validation API costs $0.00 per 1,000 phones. We check each provider's docs for 9 fields. WSAPI's docs list 1: Number.
WSAPI limits how many results you get but gives no number.
We haven't run WSAPI through [our phone validation API benchmark](https://datacircle.dev/best-phone-validation-api.txt) yet.
This plan is free. We rank 1,266 plans for phone validation APIs by price. Half the plans cost $3.55 or less per 1,000 phones. [See the best free phone validation API plan.](https://datacircle.dev/best-phone-validation-api.txt)
[GuGuData's CNY 124 (about $19) monthly plan](https://datacircle.dev/validate-phone-apis/gugudata/cny-124-monthly/llms.txt) is the cheapest paid plan per 1,000 phones. GuGuData's CNY 124 (about $19) monthly plan charges nothing per call. You get as many phones as GuGuData's rate limit allows. [Neutrino API's On-Demand plan](https://datacircle.dev/validate-phone-apis/neutrino-api/pay-as-you-go-on-demand/llms.txt) costs the least for 10,000 phones a month: $0.80.
[Trestle](https://datacircle.dev/validate-phone-apis/trestle/top-up-from-10-self-serve-pay-as-you-go-get-3-0-phone-intel-phone-validation-api/llms.txt), [Data247](https://datacircle.dev/validate-phone-apis/data247/12-pack-membership-get-v3-0-verify247-phone/llms.txt) and [Abstract API](https://datacircle.dev/validate-phone-apis/abstract-api/19-monthly-starter-5000-requests-month/llms.txt) are the best phone validation API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-phone-apis/wsapi/free-trial-post-users-check
- [Phone validation API: the best of 50+ providers compared](https://datacircle.dev/best-phone-validation-api.txt)
- Get it: https://wsapi.chat/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Request: `POST https://api.wsapi.chat/users/check`
- API key: with the plan, on https://wsapi.chat/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Its API docs: https://docs.wsapi.chat/api-reference/users/bulk-check-phone-numbers-on-whatsapp?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- Sold by: WSAPI (https://wsapi.chat?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing)
- Checked: 2026-11-09

## In the answer

- Completeness: 11%
- Number: ✓

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: 136 other calls

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Check multiple phone numbers at once to see if they are registered on WhatsApp.

## Data

- Freshness: live
- What it checks: messaging apps
- Keep data: no limit
- Use data: You agree not to use the Service to: Violate any applicable laws or regulations. Send unsolicited messages (spam), including bulk commercial messages. Harass, threaten, or abuse other individuals. Distribute malware, viruses, or other harmful software. Impersonate any person or entity, or falsely represent your affiliation with any person or entity. Interfere with or disrupt the integrity or performance of the Service. Attempt to gain unauthorized access to the Service or related systems. Violate WhatsApp's Terms of Service or any applicable third-party terms.

## Plan

- Pay: $0

## Speed

- Answer: in the call

## The call

- You send: X-Instance-Id header, phones
- Method: POST
- Path: /users/check

## About the plan

- Plan: Free Trial
- Who can get it: new users

## The 3 fields the plan's answer can hold

phone number, registered on WhatsApp, JID

## WSAPI's plans (8)

- [WSAPI, free trial, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/free-trial-post-users-check/llms.txt): $0.00 per 1,000, 11% complete, live
- [WSAPI, $5 monthly, Single Instance, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/5-monthly-single-instance-post-users-check/llms.txt): 11% complete, live
- [WSAPI, $23.75 monthly, 5 Instances, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/23-75-monthly-5-instances-post-users-check/llms.txt): 11% complete, live
- [WSAPI, $92 monthly, 20 Instances, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/92-monthly-20-instances-post-users-check/llms.txt): 11% complete, live
- [WSAPI, $51 yearly, Single Instance, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/51-yearly-single-instance-post-users-check/llms.txt): 11% complete, live
- [WSAPI, $243 yearly, 5 Instances, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/243-yearly-5-instances-post-users-check/llms.txt): 11% complete, live
- [WSAPI, $948 yearly, 20 Instances, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/948-yearly-20-instances-post-users-check/llms.txt): 11% complete, live
- [WSAPI, contact us, Resellers, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/contact-us-resellers-post-users-check/llms.txt): 11% complete, live

## WSAPI's calls (2)

- `POST /users/check`: [WSAPI, free trial, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/free-trial-post-users-check/llms.txt)
- `GET /users/{phone}/check`: [WSAPI, free trial, GET /users/{phone}/check](https://datacircle.dev/validate-phone-apis/wsapi/free-trial-get-users-phone-check/llms.txt)

## WSAPI's APIs (1)

- [WSAPI: phone validation API pricing, 8 plans, POST /users/check](https://datacircle.dev/validate-phone-apis/wsapi/free-trial-post-users-check/llms.txt)

## WSAPI: phone validation API alternatives

- [Foxentry, free trial, POST /phone/validate, Validate phone number (extended)](https://datacircle.dev/validate-phone-apis/foxentry/free-trial-post-phone-validate-validate-phone-number-extended/llms.txt): $0.00 per 1,000, 56% complete, live
- [HLR Lookups, free, 100 free lookups, POST /hlr-lookups](https://datacircle.dev/validate-phone-apis/hlr-lookups/free-100-free-lookups-post-hlr-lookups/llms.txt): $0.00 per 1,000, 56% complete, live
- [HLR Lookup, free, 200 free credits, POST /batches/{id}/sourcejson, Bulk uploads via API](https://datacircle.dev/validate-phone-apis/hlr-lookup/free-200-free-credits-post-batches-id-sourcejson/llms.txt): $0.00 per 1,000, 89% complete, live
- [seven.io, free test credit, GET /api/lookup/hlr](https://datacircle.dev/validate-phone-apis/seven-io/free-test-credit-get-api-lookup-hlr/llms.txt): $0.00 per 1,000, 78% complete, live
- [WhatsScale, free](https://datacircle.dev/validate-phone-apis/whatsscale/free/llms.txt): $0.00 per 1,000, 22% 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 2026-11-09.

- https://docs.wsapi.chat/api-reference/overview?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://docs.wsapi.chat/api-reference/users/bulk-check-phone-numbers-on-whatsapp.md?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://docs.wsapi.chat/api-reference/users/check-if-a-phone-number-is-on-whatsapp.md?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://docs.wsapi.chat/basics/free-trial?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://docs.wsapi.chat/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://wsapi.chat/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing
- https://wsapi.chat/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=phone-validation-api-pricing