Insights from the ZelNum team

Phone Validation 5 min read

VoIP Numbers: What They Are & How to Detect Them

<h2VoIP Numbers: What They Are & How to Detect Them</h2 <pA VoIP (Voice over IP) number is a phone number that routes calls over the internet...

SMS Marketing 4 min read

Facebook Number Checker Use Cases for List Hygiene and Risk Review

<h2Facebook Number Checker Use Cases for List Hygiene and Risk Review</h2 <pFacebook verification is different from other platform checks. With 2B+...

Crypto Verification 4 min read

KuCoin Email Checker API Workflow for Automated Checks

<h2KuCoin Email Checker API Workflow for Automated Checks</h2 <pIf you&8217;re screening users for KuCoin account verification — for airdrop...

Data Quality 5 min read

Plivo Alternative: Phone Lookup Service Comparison

<h2Plivo Alternative: Phone Lookup Service Comparison</h2 <pPlivo&8217;s Lookup API is solid for basic phone validation — carrier, line type, country....

API Workflows 3 min read

Viber Number Checker API Workflow for Automated Checks

The API route for Viber exists to keep the channel state current. On-Viber status is not a permanent property of a number. Accounts go dormant, numbers...

Data Quality 3 min read

Best Amazon Number Checker Tools for Batch Verification

An Amazon number checker is bought for one of two reasons: keep buyer contacts clean, or keep seller credentials honest. The tool that serves both is...

Crypto Verification 5 min read

Best CoinW Number Checker Tools for Batch Verification

<h2Best CoinW Number Checker Tools for Batch Verification</h2 <pIf you&8217;re running airdrops, screening for Sybil accounts, or verifying users for...

Data Quality 6 min read

Zalo vs Line: Asian Messaging App Verification

<h2Zalo vs LINE: Asian Messaging App Verification</h2 <pIf you&8217;re doing outreach in Southeast Asia, you can&8217;t ignore Zalo and LINE. WhatsApp...

Data Quality 3 min read

Bulk Amazon Number Checker: CSV Upload and Result Export Guide

On an Amazon file, the CSV is where relationships become visible. A single number appearing across multiple rows is not a formatting accident. It is a...

SMS Marketing 3 min read

How to Use Crypto Exchange Lookup for Bulk List Checks

On a crypto exchange, a phone number is not a contact detail. It is the anchor for KYC, the carrier of the 2FA codes, and the recovery path when an...

Phone Validation 5 min read

How to Validate Phone Numbers: Step-by-Step Guide

<h2How to Validate Phone Numbers: Step-by-Step Guide</h2 <pIf your phone list has grown past what you can check by hand, you need a bulk validator. <a...

Telegram Tools 6 min read

Bulk Telegram Number Check: Validate Your Contact List at Scale

How to Check If a Number Is on Telegram If you need to know which contacts in your list are actually on Telegram, doing it one number at a time doesn't...