We looked through thousands of Communication API documentation pages to find the best APIs for your use. Here is a list of the ones we found to be the most popular and to fit all budgets.

WHOIS API is a consumption model variant that gathers a variety of domain ownership and registration data points from a comprehensive WHOIS database

WHOIS API is a consumption model variant that gathers a variety of domain ownership and registration data points from a comprehensive WHOIS database. Developers can integrate WHOIS API into existing internal systems and commercial applications using client libraries and integration modules.

- **Comprehensive across TLDs**
Our WHOIS repository contains information from millions of active domain and subdomain records that cover more than 7,298 generic (gTLDs) and country-code top-level domains (ccTLDs).

- **Unified and fit for purpose**
Our WHOIS data can be quickly integrated into different internal systems to speed up its use by various stakeholders.

- **Handy**
Need data viewable in either Extensible Markup Language (XML) or JavaScript Object Notation (JSON)? Our API provides both output types.

- **Reliable and current**
Our WHOIS data is gathered in near-real-time, giving you exclusive access to accurate and updated information for better decision-making.

WHOIS API

Twitter Direct Message API features enable developers to build better-personalized customer experiences at scale as well as other innovative interactions.

These API features enable developers to build better-personalized customer experiences at scale as well as other innovative interactions. To help create more engaging customer service, marketing, and user engagement experiences in Direct Messages we’re providing developers access to endpoints to start conversations with a welcome message, publish messages with quick replies and media, and more.

- Sending and receiving events
- Send and receive Direct Messages.
- Welcome Messages
- Create messages that display for specific scenarios.
- Message Attachments
- Attach videos, images and GIFs.
- Quick Replies
- Prompt users for structured replies with a menu of options.
- Buttons
- Add buttons to link to websites, deep link to apps or other parts of Twitter.
- Conversation management
- Properties to help manage the conversation between multiple applications.
- Custom profiles
- Display a custom profile image and name in a Direct Message.
- Customer feedback cards
- Prompt users for NPS and CSAT feedback.

Twitter Direct Message API

 Global Phone Number Validation & Lookup JSON API

**Global Phone Number Validation & Lookup JSON API**
_Real-time REST API supporting 232 countries_

**numverify API**

NumVerify offers a full-featured yet simple RESTful JSON API for national and international phone number validation and information lookup for a total of 232 countries around the world.

Requested numbers are processed in real-time, cross-checked with the latest international numbering plan databases and returned in handy JSON format enriched with useful carrier, geographical location and line type data.

Integrating the numverify API into your application will enable you to verify the validity of phone numbers at the point of entry, protecting you from fraud and increasing good leads.

Here are some of the key **features** of NumVerify API:

- **Number Validation**
Capture only good leads, keep your user database clean and fight fraud by validating phone numbers at the point of entry into your system »

- **Simple & Secure API**
Requested using an easy-to-integrate URL structure, delivered in lightweight JSON format, and secured via 256-bit HTTPS encryption »

- **Advanced Tools**
Advanced phone number validation using the most up-to-date international numbering plans, carrier & line type detection, and location lookup »

- **Easy on your Budget**
We're offering the most cost-effective API - validate 250 phone numbers per month for free. Need more? Subscriptions start at $19.99 per month »

NumVerify API

Improve your contact rate and clean your lists with Abstract's industry-leading phone number validation API


**Phone Number Validation and Verification API**
_Improve your contact rate and clean your lists with Abstract's industry-leading phone number validation API_

- Fake and invalid number detection
- Carier and line type identification
- 190 countries supported
- Privacy friendly (GDPR, CCPA) 

**Abstract's Phone Number Validation and Verification API ensures you have clean and reliable contact lists**

- **Powerful phone validation and verification**
Validate and verify phone numbers before you save them to your database and use them to contact users to ensure you have only real, high value users and contract info.
- **Identify fake and invalid phone numbers**
We maintain a large and frequently updated database of phone numbers and carriers, including disposable, free, VOIP, and other number types to help screen low quality numbers.
- **International number and carrier support**
Abstract's database covers 190+ countries, allowing you to validate and verify phone numbers from around the world without having to be an expert in the minutiae international phone yourself.
- **Detect phone carriers and line type**
Phone validation and verification includes data like the phone carrier and line type (landline, cell phone, VOIP, etc) where possible, so you can get a full view of a phone number.
- **Get location and other valuable geo data**
Get valuable geographic information about a phone number. This includes not only country, but also region or even city-specific details in many cases.
- **Protected by bank-level security**
Security is also a top concern of ours, especially with your data. So every interaction you have with Abstract's Phone Number Validation and Verification API is secured via 256-bit SSL encryption (HTTPS).

Phone Number Validation and Verification API

Global Phone Number Validation & Lookup JSON API.

### Verify any number, anywhere
Number Verification API offers a full-featured yet simple RESTful JSON API for national and international phone number validation and information lookup for a total of 232 countries around the world.

Requested numbers are processed in real-time, cross-checked with the latest international numbering plan databases and returned in handy JSON format enriched with useful carrier, geographical location and line type data.

#### Features
**International Numbers:** Validate international phone numbers for 232 countries using their unique international dial codes.

**National Numbers:** Validate national (local) phone numbers by providing an additional 2-digit country code parameter.

**Location Data:** Retrieve valuable geographical identifiers, including country and location, with each API request.

**Carrier Detection:** Legitimize customers by retrieving details about the carrier their phone number is registered with.

**Line Type Detection:** Reduce undelivered messages and ensure right ways of communication by knowing the line type.

Number Verification API

Detects disposable, fake and throwaway email addresses in lightning speed.

### The Problem with Fake Emails
A disposable or a fake email looks like a real email address. Unfortunately, it is a throwaway address that is used once or twice and never again. So there will be no one reading all the marketing emails you send to that address.

As a serious business, you need to make sure that none of your users have are using a disposable email address to make sure you can reach them. Because there’s no one at the other end, you don’t get any engagement with such addresses.

#### But we can help!

This API is a quick, lightning speed way of detecting if an email address is disposable/throwaway or not. It is updated on a daily basis and features the most up to date database that is available. So instead of building your own service and trying to be up-to-date, just give a try to ours. It is free to try!

#### Key Features
- Updated daily.
- Fast and Efficient.
- Using the API is as easy as hitting a URL.


Disposable Email Detection API

Validates and verifies an email address assessing deliverability and quality.

#### Why use our API?
There’s plenty of significant reasons behind having proper validation in place:
- Sending emails to fake/no-longer-existent addresses will hurt your deliverability.
- Mistyping an email address will block users from confirming their account or resetting a password.
- Valid e-mail addresses, lets you stay in touch with users.
#### How it works
This API is the one and the only solid solution to verify that the e-mail address is valid, and reachable. We achieve this functionality by validation with regex, validating the DNS for MX records and than connecting the recipient's SMTP server for validation, without sending any email.

Yes! this email verification API actually connects to the mail server and checks in real-time if the email exists. We don't use historical data.This is the most robust and solid way that is possible within the SMTP protocol's limitations.

#### Features
- Syntax & Typo Check
- Free & Disposable Provider Databases
- Quality Score Feature
- Real-time SMTP MX-Records Check
- Catch-all Detection

 Email Verification API

Performs robust scoring algorithms to a given text and classifies it as spam or not.

### What does the API do?
Spam Check API performs a wide range of advanced heuristic and statistical analysis tests on email headers (if exists in text) and body text including text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases.

It will work with any text: 
- Comments. 
- e-mail. 
- HTML.
- Even plain text messages. 

You can define a threshold if you desire if you need to be more optimistic about spam messages. The threshold value can be between 1-10, of which 1 means every message will be classified as spam and 10 the opposite.

#### Features
- Easy to use!
- Pre-trained model.
- Rule and heuristic models combined.


The Top 15 Communication Apis for Developers