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A Guide to the Best Email Verification & Validation APIs of 2023

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Best for Developers
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World-class API Documentation
Easy, Lightweight API
Flexible pricing
Best for Sales Teams
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Powerful email finder
Social Media enrichment
Email campaign capabilities
Best for Marketers
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Marketing campaign execution
AI-powered verification API
Best for Monitoring Capabilities
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World-class API Documentation
Easy, lightweight API
Flexible pricing
Best for Fraud prevention
Email Hippo
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Intuitive UI and dashboard
WHOIS reporting
Data Enrichment

A Guide to the Best Email Verification & Validation APIs of 2023

Dive into this piece because it’s a masterclass on the top email verification APIs, amplifying the effectiveness of your email campaigns.

Email is king. Sure, people are on LinkedIn, and PPC can be effective – but when it comes to reaching a decision-maker, there is a reason marketers choose email.

The problem?

Marketing and sales teams have trouble building and maintaining reliable email lists. Manually verifying email addresses is time-consuming, and incorrect email addresses with high bounce rates can ruin your sender reputation.

Luckily, there are email verification and validation APIs that do that for you.

In this article, we explore the world of email verification, how you can leverage an email verification API, and review the best email verification APIs on the market.

Let’s dive in!

What is Email Verification?

Email verification is the process of determining the validity and deliverability of an email address. It consists of checking whether an email address exists, is active, and can receive emails. Email verification is important for maintaining a clean and engaged email list, preventing bounced emails, reducing spam complaints, and improving email deliverability rates.

What Does an Email Verification API do?

An email verification API allows developers to integrate email verification functionality into their applications, websites, or systems. The API will provide a set of endpoints and methods that developers can use to interact with the email verification service and perform various email verification tasks programmatically.

Here’s an overview of what an Email Verification API typically does:

  1. Syntax and Format Validation: checks the syntax and format of an email address to ensure it is free from formatting and syntax errors.
  2. Domain Verification: verifies the domain associated with the email address. The API checks if the domain exists, has valid DNS records, and is configured to receive emails.
  3. Mailbox Validation (deliverability): connects to the mail server associated with the email address and performs a mailbox validation. This checks if the mailbox exists, is active, and can receive emails.
  4. Disposable Email Address (DEA) Detection: Disposable email addresses are often used for spamming or fraudulent activities. Detecting and flagging DEAs helps minimize the risk of sending emails to them.
  5. Role Account Identification: Role accounts are generic addresses used for specific purposes, such as [email protected] or [email protected]. Knowing if an email address is a role account helps evaluate its relevance and engagement potential.
  6. Spam Detection: Email verification tools also check if the email address is associated with a known spam trap, or set up to catch and identify spammers. Sending to a spam trap can hurt sender reputation.

Developers can utilize this information to take appropriate actions, such as cleaning up their email lists, segmenting contacts, or implementing additional validation steps.

Email Validation APIs Compared

SolutionPricing Model?Offers Free Version?API DocumentationUser Dashboard
AbstractAPIMonthly SubscriptionYesExcellentNo
Hunter.ioMonthly SubscriptionYesExcellentYes
ZeroBounceMonthly SubscriptionYesAverageYes
SendGridMonthly SubscriptionYesAverageYes
Email HippoPay-as-you-goNoPoorYes

Best Email Verification/Validation APIs of 2023

1. AbstractAPI

Abstract's Email validation api/verification API

Best For: Developer teams building custom applications

  • World-class API Documentation
  • Easy, lightweight API
  • Flexible pricing

Abstract’s APIs offer a host of time-saving APIs to help a variety of business use cases. One of the more popular APIs is an email verification and email validation API. With this API, you can easily do mailbox verification to improve deliverability and clean your email lists in bulk. Abstract’s documentation is second to none, with plenty of resources in different programming languages.

Top Features

  • Typo check and auto-suggest. This API checks for typos in your email lists. It also recommends a likely replacement.
  • Role Checking. Automatically check for role-based emails without having to manage or create your own rules.
  • Secure and reliable. With SSL encryption, all data that is sent to Abstract’s email validation API is secure with the latest protocols.
  • Extensive documentation. Abstractapi is in the business of APIs – they offer extensive API docs, how-to guides, and examples.


  • Easy to use with extensive documentation
  • Affordable, with transparent pricing models
  • Has more features than most verification APIs, including spellcheck, autocomplete, and other methods that might only be available in a validation API.


  • If you’re not a developer or don’t have experience with APIs it might be a challenge to learn.
  • There is no front-end, database, or CRM component. Some competitors have more feature-rich capabilities.

Customer Support

AbstractAPI offers extensive customer support, especially for enterprise clients. On top of that, their documentation is second-to-none. You’ll be able to troubleshoot and resolve issues from their articles.


AbstractAPI offers a flexible pricing model with over 5 options including a free version. Here is the breakdown.

  • Free. 100 Requests at one request per session. This is great if you’re starting out and want to verify the tool as a proof of concept.
  • Starter @ $9/mo. Starter comes with 5,00 requests per month and 3 requests per second. This is fine for smaller applications and smaller databases.
  • Standard @ $49/mo. 50,000 requests per month
  • Business @ $99/mo. 100,000 requests per month
  • Pro @ $199/mo. 250,000 requests per month
  • Growth @ $499/mo. 750,000 requests per month and up to 100 requests per second.

2. ZeroBounce

zerobounce email validation api

Best For: IP, domain, and reputation monitoring

  • World-class API Documentation
  • Easy, lightweight API
  • Flexible pricing

ZeroBounce finds, validates, and scores email addresses for sales and marketing teams. With ZeroBounce you can enjoy more than just email verification and email validation API.

Top Features

  • Blacklist monitoring. ZeroBounce will monitor your IP addresses against blacklists so you can quickly work to get delisted and work to repair your sender reputation.
  • Bulk email list evaluator. You can upload a TXT or CSV file to easily validate and verify multiple emails at a time. ZeroBounce even claims a 99% accuracy. The results will go beyond surface-level validation and verification so you’re not sending to invalid email addresses.
    • Spam Traps. Delivering messages to a spam trap has consequences. Once identified, they can blacklist your address and all other email addresses on your domain.
    • Syntax and Typos. If there is a typo in your address, or if you’re missing valid email syntax, Zerobounce will alert you.
    • Catch-all domains.
    • Abuse. Zerobounce can help catch bad actors who report senders purely to cause their reputation harm.
    • Do not mail. Avoid toxic, role-based, or global suppression emails.
  • Email Finder. Email finder allows you to search by name and domain to find the right decision maker.
  • Zerobounce iOS app. This is a huge value-add! With the mobile app, you can check and validate email addresses on the road.
  • Accuracy. ZeroBounce is accurate, so you sent it to only valid email addresses.


  • Goes beyond an email validation API and includes many more features.
  • Offers an entire suite of products useful for any organization that focuses on prospecting.
  • Impressive user dashboard that displays all relevant metrics and activities.
  • Integration through Zapier. You can leverage Zapier to integrate ZeroBounce with thousands of other applications.
  • Custom and flexible pricing. You pay per ‘credit’ so can specify how many credits you’d like to purchase at once, or chose a recurring monthly pricing model.


  • Pricey. Many reviewers claim ZeroBounce is more expensive than some competitors

Customer Support

ZeroBounce is renowned for its excellent customer service. Many reviewers have indicated that their queries and concerns were quickly resolved.


ZeroBounce offers pay-as-you-go and monthly pricing options. For pay-as-you-go, you can purchase a bucket of ‘credits’. Credits correspond to the number of email addresses you’ll need to verify. You can also refill credits every month for a discounted price.

In addition, ZeroBounce offers the following monthly pre-built plans. These check mail servers, and mailbox providers, provide a set amount of blacklist monitors, and maximum query amount.

  • Free. Used for tester purposes.
  • Starter @ $39/mo. Includes 1,000 monthly queries, 50 mail server tests, and inbox tests as well as 10 blacklist monitors.
  • Team @ $99/mo. Includes 10,000 queries, 100 mail server tests, and inbox tests as well as 20 blacklist monitors.
  • Pro @ $249/mo. Includes 25,000 queries, 500 email server tests, and inbox tests as well as 50 blacklist monitors.
  • Enterprise @ $999/mo. Includes 200,000 queries, unlimited email server tests, and inbox tests as well as unlimited blacklist monitoring.


Email Validation api Best Email validation tools.

Best For: Sales, prospecting, and outreach.

  • Powerful email finder
  • Social Media enrichment
  • Email Campaign capabilities offers robust email verification and validation APIs on top of an impressive platform. With impressive single and bulk email finders, verifying, and validating capabilities – is great for both small and large sales teams.

Top Features

  • Email Finder.‘s email finder service and email lookup tool lets you quickly find email addresses associated with a specific domain or company. It utilizes multiple data sources to provide a more accurate result.
  • Email Verifier. Verify the deliverability and validity of email addresses and eliminate invalid or inactive addresses from your email lists. It also checks for and removes spam traps and role-based emails. You’re also able to leverage their email validation APIs to integrate with your own native applications or build your own email validation service. You can claim a free API key here.
  • Domain Search. Users can explore and discover email addresses associated with a particular domain.
  • Email Campaigns. Create and manage email campaigns directly within the platform. You can customize templates, schedule email deliveries, and track their performance.


  • can provide highly accurate email addresses due to its extensive database. This reliability makes working with email finder very satisfying.
  • Of all the other email validation/email verification tools, this platform looks the best. The interface is intuitive, making it easy for both beginners and experienced users to navigate.
  • A vast database gives users access to a ton of email addresses. This comprehensive coverage enables you to find relevant contacts from various industries and domains, expanding your outreach opportunities.


  • Reviewers would like it to have a social media research tool.
  • Very limited free version

Customer Support

  • Reviewers consider customer support to be outstanding for, with many satisfied customers.

Pricing comes with three plans (besides the free option).

  • Starter @ $49/mo. This includes 500 monthly searches and 1,000 monthly verifications.
  • Growth @ $149/mo. 5,000 monthly searches and 10,000 monthly verifications.
  • Business @ $490/mo. 50,000 monthly searches and 100,000 monthly verifications. You’ll also get a dedicated account manager to help quickly resolve issues.

4. SendGrid

Email Validation API SendGrid

Best For: Marketing and Segmentation

  • Marketing campaign execution
  • AI-powered verification API
  • Scalable

SendGrid helps businesses effectively manage their email communications. With its powerful features and scalable infrastructure, SendGrid enables businesses to send high-volume emails while maintaining good deliverability, engagement, and analytics.

Top Features

  • Email Delivery. SendGrid’s email delivery capabilities are great. With reliable infrastructure and advanced algorithms, SendGrid can optimize email delivery rates, which minimizes the risk of emails being marked as spam or bouncing.
  • Marketing Campaigns. One thing that sets SendGrid apart is its advanced marketing features. These features let you create and manage targeted email marketing campaigns. SendGrid provides an intuitive campaign builder, customizable templates, and advanced segmentation options.
  • Machine Learning Email Validation. SendGrid’s email verification and validation APIs leverage machine learning algorithms that are trained from 100 billion emails per month. Because of this, the tool is always getting smarter.


  • Scalable Infrastructure. SendGrid’s infrastructure is built to handle high email volumes, making it a reliable choice for businesses with growing subscriber lists. The platform’s scalability allows you to send thousands or even millions of emails without compromising on delivery speed or quality.
  • Robust API. SendGrid provides a powerful API that enables seamless integration with your existing applications, CRM systems, or marketing tools. In addition, they offer extensive and interactive API documentation with libraries in several different languages.


  • Complex. While SendGrid offers extensive features and customization options, beginners may find the platform overwhelming. The wide range of functionalities requires a bigger learning curve than other tools on this list.
  • No Email Validation or Verification for lower-tier plans. While SendGrid provides a freemium version, you won’t be able to take advantage of real-time validation.

Customer Support

SendGrid reviews find customer support to be top-of-the-line, with bigger accounts having more hands-on support.


SendGrid offers flexible pricing and divides plans into two categories.

SendGrid Pricing Email validation tool
  • Email API Plans. These plans are associated with using SendGrid’s email APIs along with delivery optimization tools, analytics, and deliverability insights. With each tier, you obviously get more features, and the pricing per email drops.
    • Free email API – includes 100 emails per day for life
    • Essentials start @ $19.95/mo with increases based on the # of email sends.
    • Pro starts at $89.95/mo which increases based on the # of email sends. Includes a dedicated IP and up to 2,500 verifications.
    • Premier has custom pricing and is for enterprise clients.
  • Marketing Campaign Plans
    • Free
    • Basic @ $15/mo
    • Advanced @ $60/mo

5. Email Hippo

Email Hippo email scoring email verifiers

Best For: Fraud prevention

  • Intuitive UI and dashboard
  • WHOIS reporting
  • Data Enrichment

Since 2009, Email Hippo has been providing marketers, developers, and ‘fraud fighters’ with a great email validator. Email Hippo uses 74 large data sets to compare and validate emails in addition to checking for mistyped email addresses to maximize inbox placement.

Top Features

  • Data Enrichment. Email Hippo’s product ‘MORE’ provides a rich and robust email verification API to validate and verify email addresses. You’re also able to automatically validate and clean email addresses at the point of capture on lead capture forms and sign-up pages. You can also integrate this API with your CRM to detect spam traps, disposable email providers, and fake email addresses.
  • ASSESS is a fraud prevention API. It performs an analysis of the data behind every signup and assigns a numeric risk level to every result. The result is a single Trust Score, which businesses can use to identify potential fraud.
  • WHOIS API delivers structured domain data. It provides reporting across the WHOIS universe and the API calls 2,500 databases to return reliable data.


  • Bulk Verification Efficiency. The ability to verify email addresses in bulk is a significant advantage of Email Hippo.
  • Data Enrichment Capabilities. The data enrichment services offered by Email Hippo provide valuable additional information about your contacts, enabling you to personalize your communication and improve customer segmentation.
  • Nifty UI. The product dashboard is pretty neat. You can get at-a-glance information on performance, API usage, cumulative usage, and more.


  • No Clear Pricing Information. I couldn’t tell you how much Email Hippo costs until I signed up. From there you can see that they charge by the product and the number of needed API calls.
  • Limited Integration Options. While Email Hippo provides a real-time API, it may have limited pre-built integrations with specific platforms or applications compared to some other providers. This might require additional development time.
  • No Free API key. I didn’t see an option to use a free API key, so you may not be comfortable purchasing if you’re not able to test it out.

Customer Service

Email Hippos has a 24/7 support line which is a great resource for new users. It also has detailed integration docs and FAQs integrated directly into the product, so you don’t have to go hunting for resources.


As mentioned before, pricing is not that transparent. However, they seem to price based on product and usage. Here are their four products.

  • CORE
  • MORE

Each product offers tiered pricing based on usage.

Email Hippo Email validator email validation tools pricing

6. BriteVerify from Validity

BriteVerify Automatically checks emails, domain names, and more. Best Email Verification/Validation API

Validity’s BriteVerify is an advanced email verification service that aims to enhance the email quality, deliverability, and accuracy of your contact list. With its comprehensive validation features and reputation for exceptional customer service, BriteVerify offers businesses a great solution to maintain clean and effective email campaigns.

Top Features

  • Phone Number and Mail Verification. You can leverage phone and mail verification APIs to validate all types of contact information in real time.
  • Data Append Services. Append services and can provide additional details like name, locations, and social media info.
  • Reporting and Analytics. BriteVerify provides detailed reports and analytics on verification results and provides insights into the health of your email list. You can also track bounce rates, deliverability rates, and other metrics.


  • Exceptional Customer Service. Validity is known for its outstanding customer service. According to reviews, the support team is responsive, knowledgeable, and proactive.
  • Real-time API Integration. The real-time API integration offered by BriteVerify allows for integration with existing systems. You can validate email addresses in real-time during data entry on sign-up forms and help prevent false entries.
  • Bulk Verification Efficiency. The bulk verification feature works with Demand Tools to not only verify but load bulk results into your CRM as leads or contacts.


  • Pricing Structure. Pay-as-you-go is not for everyone. Accidentally going over the limits can cost you more.
  • Cost. It’s more expensive than some competitors.

Customer Service

BriteVerify has a highly-rated customer service team. Billing and account questions are resolved quickly, according to reviewers.


BriteVerify offers a pay-as-you-go pricing model.

pay-as-you-go. Pay per request with Briteverify

7. DeBounce

DeBounce. Best Email Verification API. Monitor IP reputation

DeBounce is a sleek email validation/verification tool. With the ability to spin up multiple API keys, integrated and real-time dashboards and reports, and extensive API documentation, DeBounce is great for teams of all sizes.

Top Features

  • Anti-greylisting Technology. You can actually simulate an email engine to test and reduce deliverability issues.
  • Team Account. You can use one team account and add multiple team members to one DeBounce account. You’ll share a pool of the same credit source.
  • Native Integration. Easily integrates with popular email marketing tools and CRMS like HubSpot, MailChimp, Drip, Moosend, WooCommerce, Drupal, and Klavio.
  • Automated Validation. Connect with your ESP and automatically validate emails every day.


  • UI/UX. Debounce has an awesome UI. You can easily jump between tools like bulk and single verification, list monitoring, and integrations. Everything that you need is right in front of you.
Analysis result returned payload in json format
  • Automated Validation. The automated email validation is great. You can integrate with your ESP to clean your email list daily so that your emails are always clean and verified.
  • API Documentation. The API Documentation is excellent. You can view detailed instructions in the programming language of your choice.View API documentation for client libraries api documentation - unBounce


  • Limited Additional Data Enrichment. Compared to some other providers, Debounce may have limited options for enriching data beyond email validation. Businesses looking for additional data appending services, such as social profiles or demographic information, may need to seek alternative solutions.
  • Pay-as-you-go. It’s not for everyone. It offers the flexibility of sharing an account, but you don’t get the heavier discounts you may get from a bundle.

Customer Service

DeBounce has tons of online resources if you encounter a problem. They also get great customer service reviews.


DeBounce has simple ‘pay for what you need’ pricing. The more credits you buy, the more of a discount you get.

Pay per request. DeBounce pricing


What is the difference between email validation vs email verification?

Email validation is the process of verifying the syntax and format of an email address. During validation, various checks are performed to ensure that the email address includes an “@” symbol, a domain name, and a top-level domain (TLD) extension. It helps identify basic errors or typos that might render an email address invalid. Validation does not guarantee the existence or deliverability of an email address, but it helps filter out obvious errors before proceeding with further actions.

Email verification goes beyond validation. involves a more in-depth process that interacts with the mail server associated with the email address to determine its status. Verification typically includes sending a test email or pinging the mail server to check if the address is valid and active. It confirms whether the email address is currently active, able to receive emails, and not flagged as a potential spam trap or invalid address.

What does an email validator do?

An email validator is a tool that performs email validation. It helps determine the validity and quality of an email address based on various checks and criteria. Depending on the tool, it may include a combination of validation and verification checks like a syntax check, domain check, disposable email check, DNS validation, and SMTP check.

How do I validate a list of email addresses?

You can validate a list of emails through a bulk email validation tool or API. Most email verification APIs provide a service like this. By reading a CSV or TXT file of emails, the bulk verifier can process and check multiple emails at the same time. You can then use the validated list, remove invalid emails, and upload them to your database.

Is pay-as-you-go worth it?

Depending on your use case, it might be worth leveraging pay-as-you-go. It’s good for smaller teams that may share an account. You need to stay on top of how many credits you are using so you don’t risk going over or hitting the limit.


There is no shortage of great email verification APIs out there. Each of them plays to their own strengths. The key is choosing a tool that works best for your team and their needs. Remember to factor in the pricing model and consider their other offerings that go beyond email verification and validation.

5/5 - (5 votes)