CheckNumber API - Phone Number Verification Service

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

API Introduction

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`

Product Catalog

Product	Task type	Return fields
CheckNumber	`tg`	`number`, `activated`
Activity Checker	`tg_active`	`number`, `activated`, `uid`, `username`, `lastseen`, `activedays`, `member`
Profile Checker	`tg_avatar`	`Phone`, `activated`, `uid`, `username`, `Gender`, `Age`, `Ethnicity`, `Avatar`, `Last Online Time`, `Active Days`, `Is Member`, `first_name`, `last_name`

Product	Task type	Return fields
CheckNumber	`ws`	`number`, `activated`
Activity Checker	`ws_active`	`number`, `activated`, `activetime`, `activedays`, `business`
Profile Checker	`ws_avatar`	`number`, `activated`, `age`, `avatar`, `category`, `gender`, `hair_color`, `number`, `skin_color`

CheckNumber

Product	Task type	Return fields
Validity Checker	`phoneCheck`	`number`, `activated`
Activity Checker	`active_check`	`number`, `activated`
High-Value Checker	`high_value_users`	`Mobile Number`, `Result`

Viber

Product	Task type	Return fields
CheckNumber	`viber`	`number`, `activated`
Activity Checker	`viber_active`	`number`, `activated`, `mid`, `last_online_time`, `active_days`
Profile Checker	`viber_senior`	`number`, `activated`, `last_online_time`, `active_days`, `mid`, `nickname`, `person_count`, `avatar_type`, `age`, `skin_color`, `gender`, `avatar`

iMessage

Product	Task type	Return fields
CheckNumber	`imessage`	`number`, `activated`

RCS

Product	Task type	Return fields
CheckNumber	`rcs`	`number`, `activated`, `system`

Signal

Product	Task type	Return fields
CheckNumber	`signal`	`number`, `activated`

VK

Product	Task type	Return fields
CheckNumber	`vk`	`number`, `activated`

Apple ID

Product	Task type	Return fields
CheckNumber	`apple`	`number`, `activated`
Email Checker	`apple_email`	`email`, `activated`

Facebook

Product	Task type	Return fields
CheckNumber	`facebook`	`number`, `activated`
Email Checker	`facebook_email`	`email`, `activated`

Amazon

Product	Task type	Return fields
CheckNumber	`amazon`	`number`, `activated`
Email Checker	`amazon_email`	`email`, `activated`

Instagram

Product	Task type	Return fields
CheckNumber	`instagram`	`number`, `activated`
Email Checker	`instagram_email`	`email`, `activated`

MAX

Product	Task type	Return fields
CheckNumber	`max`	`number`, `activated`
Profile Checker	`max_full`	`number`, `activated`

Netflix

Product	Task type	Return fields
CheckNumber	`netflix`	`number`, `activated`
Email Checker	`netflix_email`	`email`, `activated`

Line

Product	Task type	Return fields
CheckNumber	`line`	`number`, `activated`
Profile Checker	`line_senior`	`number`, `activated`

X (Twitter)

Product	Task type	Return fields
CheckNumber	`twitter`	`number`, `activated`
Email Checker	`twitter_email`	`email`, `activated`

Telegram (username)

Product	Task type	Return fields
Registration Checker	`tg_username`	`username`, `activated`
Profile Checker	`tg_username_profile`	`username`, `activated`, `nickname`, `avatar`, `gender`, `age`, `skin_color`
Full Checker	`tg_username_full`	`username`, `activated`, `nickname`, `avatar`, `gender`, `age`, `skin_color`, `user_id`, `active_days`, `is_vip`, `is_frozen`

Product	Task type	Return fields
CheckNumber	`linkedin_phone`	`number`, `activated`
Email Checker	`linkedin`	`email`, `activated`
Email Profile Checker	`linkedin_profile`	`email`, `activated`, `country`, `gender`, `industry`, `job_title`, `inferred_salary`

Zalo

Product	Task type	Return fields
CheckNumber	`zalo`	`number`, `activated`

TikTok

Product	Task type	Return fields
CheckNumber	`tiktok`	`number`, `activated`, `username`, `uid`

Microsoft

Product	Task type	Return fields
CheckNumber	`microsoft`	`number`, `activated`

Snapchat

Product	Task type	Return fields
CheckNumber	`snapchat`	`number`, `activated`

Messenger

Product	Task type	Return fields
CheckNumber	`messenger`	`number`, `activated`

GoTo

Product	Task type	Return fields
CheckNumber	`goto`	`number`, `activated`

Threads

Product	Task type	Return fields
CheckNumber	`threads`	`number`, `activated`

Spotify

Product	Task type	Return fields
Email Checker	`spotify_email`	`email`, `activated`

Band

Product	Task type	Return fields
CheckNumber	`band`	`number`, `activated`

DHL

Product	Task type	Return fields
CheckNumber	`dhl`	`number`, `activated`

Sideline

Product	Task type	Return fields
CheckNumber	`sideline`	`Number`, `activated`

Airbnb

Product	Task type	Return fields
CheckNumber	`airbnb`	`number`, `activated`

Pornhub

Product	Task type	Return fields
Email Checker	`pornhub`	`email`, `activated`

Temu

Product	Task type	Return fields
CheckNumber	`temu`	`number`, `activated`

Exchange Registration Checkers

Binance

Product	Task type	Return fields
CheckNumber	`Binance`	`number`, `activated`
Email Checker	`binance_email`	`email`, `activated`

KuCoin

Product	Task type	Return fields
CheckNumber	`Kucoin`	`number`, `activated`
Email Checker	`kucoin_email`	`email`, `activated`

Htx

Product	Task type	Return fields
CheckNumber	`htx`	`number`, `activated`
Email Checker	`htx_email`	`email`, `activated`

CoinW

Product	Task type	Return fields
CheckNumber	`coinW`	`number`, `activated`
Email Checker	`coinw_email`	`email`, `activated`

Crypto.com

Product	Task type	Return fields
Email Checker	`crypto_email`	`email`, `activated`

Email And Global Carrier Checkers

Email Validation

Product	Task type	Return fields
Upload Task	`email_check`	`email`, `activated`

Global Carrier Checker

Product	Task type	Return fields
Global Carrier Checker	`usaCarrier`	`number`, `number_type`, `country_code`, `carrier`, `underlying_carrier`, `region`, `city`

Advanced US Carrier Checker

Product	Task type	Return fields
Advanced US Carrier Checker	`us_carrier_premium`	`Number`, `number_type`, `carrier`, `city`

Shared utilities

API	Description
Global Phone Carrier Inquiry	Legacy synchronous single-number carrier lookup; not part of the 64-product catalog.
Balance Query API	Query available account balance.