CheckNumber API - Phone Number Verification & Validation Service

Welcome to CheckNumber API — the leading phone number verification and validation service for developers and businesses worldwide.

What is CheckNumber?

CheckNumber provides advanced phone number verification APIs that help you validate and verify phone numbers across 20+ platforms in bulk. Whether you need to verify WhatsApp registrations, detect social media accounts, check cryptocurrency exchange users, or query phone carrier information, CheckNumber has you covered.

Typical use cases:

Marketing list cleaning — remove inactive numbers before sending campaigns
Fraud prevention — verify user-provided phone numbers on registration
CRM enrichment — identify which platforms your contacts use
Crypto exchange KYC — cross-check user phone numbers against exchange registrations

Quick Start

1. Get your API Key

2. Submit a batch task

Upload a .txt or .csv file with one phone number per line (E.164 format, e.g. +8613800138000):

curl --location 'https://api.checknumber.ai/v1/tasks' \
--header 'X-API-Key: YOUR_API_KEY' \
--form 'file=@"./numbers.txt"' \
--form 'task_type="ws"'

3. Poll for results

curl --location 'https://api.checknumber.ai/v1/gettasks' \
--header 'X-API-Key: YOUR_API_KEY' \
--form 'task_id="TASK_ID_FROM_STEP_2"'

When status becomes exported, download the result file from result_url.

API Overview

Item	Details
Base URL	`https://api.checknumber.ai`
Authentication	`X-API-Key` header
Submit task	`POST /v1/tasks` (multipart/form-data)
Query status	`POST /v1/gettasks` (form-data)
Check balance	`GET /v1/balance`
File format	`.txt` or `.csv`, one entry per line
Max batch size	1,000,000 entries per task

Authentication

All requests require your API key passed in the request header:

X-API-Key: YOUR_API_KEY

Task Status

Status	Meaning
`pending`	Task queued, waiting to start
`processing`	Task is being processed
`exported`	Results ready, download from `result_url`

API Reference

Phone Number Detection

Our comprehensive phone number verification APIs verify account registration, detect active users, analyze profiles, and identify platform-specific information across 20+ platforms.

API	task_type	Description
Telegram Checker	`tg`	Telegram account registration check
Telegram Days Checker	`tg_active`	Telegram last online days
Telegram Age & Gender Checker	`tg_avatar`	Telegram avatar, age, gender analysis

API	task_type	Description
WhatsApp Checker	`ws`	Bulk WhatsApp registration check
WhatsApp Days Checker	`ws_active`	Last online days, business status, signature
Whatsapp Age & Gender Checker	`ws_avatar`	Avatar, age, gender, skin color analysis

Other Platforms

API	task_type	Description
Facebook Checker	`facebook`	Facebook account verification
Instagram Checker	`instagram`	Instagram account verification
Twitter Checker	`twitter`	Twitter account verification
Apple Checker	`apple`	Apple account check by phone number
iMessage Checker	`imessage`	iMessage (Apple) activation check
Rcs Checker	`rcs`	RCS (Rich Communication Services) support check
Line Checker	`line`	Line account registration check
Zalo Checker	`zalo`	Zalo account registration check
Viber Checker	`viber`	Viber account registration check
Viber Days Checker	`viber_active`	Viber last online days
Viber Age & Gender Checker	`viber_senior`	Viber avatar, age, gender analysis
Amazon Checker	`amazon`	Amazon account check by phone number
Microsoft Checker	`microsoft`	Microsoft account check by phone number

Cryptocurrency Exchange Detection

Verify phone number registration across major cryptocurrency exchanges and trading platforms.

API	task_type	Description
Binance Checker	`Binance`	Binance registered account check
Kucoin Checker	`Kucoin`	KuCoin registered account check
CoinW Checker	`coinW`	CoinW registered account check
Htx Checker	`htx`	HTX (Huobi) registered account check
Mexc Checker	`mexc`	MEXC registered account check

Email Detection

Verify email addresses linked to major platforms and services.

API	task_type	Description
Netflix Email Checker	`netflix`	Netflix account check by email
Apple Email Checker	`apple_email`	Apple account check by email
Amazon Email Checker	`amazon_email`	Amazon account check by email
Facebook Email Checker	`facebook_email`	Facebook account check by email
Mexc Email Checker	`mexc_email`	MEXC account check by email

Carrier Detection

Identify phone number carriers and regional information.

API	task_type	Description
Carrier Detection	—	Phone number carrier, region, type lookup

Account Management

Manage your CheckNumber account and monitor usage.

API	Method	Description
Balance Query API	`GET /v1/balance`	Query available account balance