30 Best Email Verification and Validation API Tools for Developers

Email has been one of the core communication channels of the internet since its inception and is still in wide use today. Both businesses and applications rely on emails to send relevant information, such as transaction confirmations, to customers and prospective users. However, due to the open access nature of emails, scammers and spammers have easily exploited the medium, which in turn has forced service providers to create spam filters that only allow authentic messages to reach the user's inbox.

Email service providers use many metrics to assign a level of authenticity to your email, and one of the most important metrics is your bounce rate. This is the percentage of emails that never reach the recipient’s inbox and usually occurs when you try to send email to an invalid or unverified email address. It’s therefore good practice to validate and verify email addresses before you add a new address to your list. The validation and verification of emails are two different processes, as described below:

Validation: Validation of emails ascertains whether an email address is valid. It checks for the general format of email addresses, including typographical errors. It does not check whether the email address actually exists, but just by validating emails you can eliminate many bad email addresses from your list.

Verification: Email verification goes a step further than validation, as it checks whether an email address exists. Emails sent to verified email addresses won’t bounce, but verification is a much more complex process requiring expertise in email and associated technologies. Verified emails are much more trustworthy than email addresses that are only validated.

It’s always a good idea to validate and verify email addresses. Fortunately, you don’t need to build validation or verification services from scratch, as you can rely on API tools from other developers to achieve the same result.

To help you out, we’ve compiled a list (in alphabetical order) of the 30 best API tools developers can use to validate or verify emails.

1. Abstract Email Validation and Verification API

Abstract offers email validation and verification APIs for developers. Some of the core features of Abstract include real-time MX & SMTP check, typo checking, and checking for disposable email providers. The service also complies with GDPR and CCPA, making it privacy friendly. Subscribing to the free tier entitles you to one request per second and up to 100 requests every month, while paying subscribers have a higher number of requests.

2. APILayer Email Verification API

APILayer is a marketplace for APIs with a powerful API to validate and verify email addresses. The service has a free tier that accepts 50 requests per month at a maximum rate of 5 requests per day. It works by validation with Regex, DNS records, and SMTP servers, can check for disposable emails, role email addresses (for example, sales@yoursite.com) and can even determine if the recipient’s inbox is full. The paid service starts at $5.99 for 100 requests per day.

3. BigData Cloud Email Address Verification API

BigData Cloud provides various APIs for eCommerce, SaaS, ad agencies, financial institutions, and CRM systems. The service has an API to verify email addresses, checks for syntax and also checks the mail server configurations of email addresses. As an added bonus, the service also includes a list of abusive emails you can use to blacklist addresses. The service is free for up to 1,000 requests per month and the paid tier starts at $1 per additional 1,000 requests.

4. Breadcrumbs

Breadcrumbs is a service for Marketing Qualified Leads (MQL) through machine learning. Breadcrumbs has an email verification service to clean up mail lists, allowing you to clean up both individual emails or emails in bulk. An additional benefit is that it easily integrates with HubSpot, while integration with MailChimp is also in the works. The email verification tool is included with a Breadcrumbs subscription and the service starts at $799 per month.

5. CaptainVerify

A popular service to validate and verify email addresses in your list, CaptainVerify also provides a statistical report of your email database. This makes cleaning up your list easier. The service also assists in improving the deliverability of your email program and complies with GDPR safety standards. The service charges $7 for verifying 1,000 email addresses.

6. Clearout Email Finder & Email Verification Service

Clearout helps businesses to discover, verify, and convert leads. The service also helps to improve the deliverability rate and decrease hard bounces. Clearout integrates with a number of high-profile services, including HubSpot, MailChimp, Google Sheets, Zapier and WordPress, and has extensive documentation for developers. There’s a pay-as-you-go pricing structure that you can tailor to your needs, as well as a monthly or annual subscription service.

7. DeBounce

DeBounce helps you detect disposable emails, deactivated emails and spam-traps. The various features of DeBounce help to increase your sending reputation and avoid wastage of resources. The service integrates with most marketing, email, and CRM platforms and has a pay-as-you-go structure that goes as low as $ 0.0003 per verification.

8. Elastic Email

Elastic Email is an email marketing service that focuses on user-friendliness for developers. It comes with the Elastic Email marketing suite and includes a verification service to ensure you reach the right audience. You can also subscribe to just the verification service via an API. The price for the separate service starts at $1 per 1,000 email verifications.

9. Email Checker

The service checks MX records and domain records to verify email addresses. It can be used to check a single email address without any charges and the service also has a premium plan and an API that supports bulk verification. Email Checker also gives importance to the privacy of subscribers and email addresses.

10. Email Hippo

Specializing in email verification for marketers, developers and fraud fighters, the comprehensive API checks email addresses quickly and analyzes 74 data points about every email address that is being tested. It integrates with any enterprise system and is easy for developers to work with. The service has a free trial that can be used to test the service and you can subscribe to paid tiers once you find the service useful.

11. Emailable

Emailable is an accurate and secure email checker. The service helps to improve the deliverability of emails and in turn, increases the return on investment for email marketing efforts. The service also has a supporting API for developers and includes extensive documentation, making this service very developer-friendly. You can try the service without charge and receive 250 free credits on sign-up. The API supports coding in JavaScript, Python, and Ruby and can be easily integrated with most enterprise applications.

12. Hunter Email Verifier API

Hunter.io is a service to discover professional email addresses. Hunter also offers an API for email verification and includes comprehensive documentation for developers. The API can be used both for searching the Hunter database and for email verification. You can use the free API key to verify up to 50 emails every month, while the paid subscription starts at $49 per month to verify 1,000 emails.

13. Infomatica Email Verification

Informatica is an enterprise-grade cloud data management service that includes an email verification API. The email in any database can be verified in real-time, helping you to eliminate malicious email addresses and improve deliverability. Email verification is included with the Cloud Data Integration subscription, which itself has a free 30-day trial period.

14. IP Quality Score Email Verifier

IP Quality Score provides fraud prevention solutions and APIs for enterprises. An email verification tool comes as part of the package and you have the ability to verify emails in bulk with CSV files. The website also offers a portal where you can check individual email addresses free of charge.

15. Kickbox

Kickbox is a trusted, secure, and accurate email verification service. The API from Kickbox can be used to test, monitor and optimize your email programs, helping to improve email deliverability and the reputation of your mail servers. The email verification API provides verification services in real-time and can be integrated with other SaaS services. The price for the service starts at $5 for 500 verifications.

16. Loquate

Loquate is an address verification service. In addition to verification of physical addresses, the service also helps to verify email addresses. The email verification API from Loquate can be used to reduce bogus registrations in addition to increasing email deliverability and improving email reputation. There is a free trial for the service that is valid for 14 days.

17. Mailgun Email Validator

Mailgun is a popular transactional email API service from Sinch that includes an API for email validation and verification. It helps to catch bad email addresses in real-time and improve the deliverability rates of marketing campaigns. The email validator can also be used with CSV files. Validating emails with Mailgun comes free with a subscription, and the service itself can be tried free of charge for a period of three months.

18. NeverBounce

NeverBounce is a service to improve email deliverability. It comes with an email verification API to verify emails in real-time at the point of entry. This makes sure that your email list is clean from the beginning. NeveBounce also easily integrates with services like Zapier, Stripe, MailChimp, Salesforce, Intercom, and many more. If you’re interested, you can create a free account to book a demo and receive free credits in the process.

19. Precisely Email Verification API

Precisely is a data integrator for enterprise applications. The service has a host of APIs for developers and email verification is just one of them. The API helps to correct and validate bad email addresses and enables you to clean your email database. The application supports multiple programming platforms and languages and comes with a 30-day free trial and 2,500 credits.

20. QuickEmailVerification

An affordable email verification service with advanced features, QuickEmailVerification ensures a deliverability rate of more than 99% for your email programs. The service has the option to verify emails in bulk with CSV files and email verification APIs. It also integrates well with ActiveCampaign, CampaignMonitor, Drip, HubSpot, MaiChimp, SendGrid, WordPress, Zapier, and many other services.

21. SendGrid Email Address Validation API

SendGrid is one of the most popular email marketing services and includes an email validation API for real-time verification of user emails. The service also uses machine learning to clean email lists and reduce bounce rates. You can try the service for free and you won’t need to submit your credit card for the trial.

22. Snov.io Email Verifier

Snov.io is a sales CRM solution that promises better leads and conversions and the email verifier is a key part of that. You can test individual emails for free at the website, while the API supports bulk email verification with CSV lists. However, the service cannot verify emails from catch-all domains.

23. Sparkpost Recipient Validation

Sparkpost is a popular email intelligence service to improve the deliverability of email campaigns. Called Recipient Validation, you can validate and verify addresses before the emails are sent, thereby helping to reduce hard bounces and improve deliverability. Like many other services, you can request a demo before making the purchase decision.

24. Truemail

An affordable email verification service with a powerful API, it promises a deliverability rate of more than 99%. Truemail also integrates with all the major marketing and CRM platforms, with a key feature of the service being the speed of verification. You can also get 50 verifications for free just by signing up.

25. Validity

Validity is a service to improve email marketing performance by improving deliverability. Validity achieves this by verifying every email before it is sent. The API can be used to increase inbox placement and maximize subscriber reah and is a part of the Validity suite of services.

26. Verifalia

Verifalia is a service dedicated to email verification. The API from the service helps to clean and verify emails in real-time and you can test the service to verify individual emails at the website. The API supports bulk and real-time verification and there are open-source SDKs available for free. The API also supports multiple programming languages such as Ruby, Python, JavaScript, Java, and PHP.

27. Verify-Email.org

It is a popular email verification platform that checks for format, syntax, domain name validity, and SMTP servers. Fast email verification is also available from the service for bulk and real-time verification. The service has one-time plans and monthly plans, with one-time plans starting at $9 for 2,000 email verifications and monthly plans starting at $25 per month to verify 10,000 emails.

28. WhoisXML API

WhoisXML is an enterprise security company focusing on domain and IP data intelligence. The company has an API to validate emails, which can also be used to check the existence, validity, and quality of any email address. You can get started with 1,000 free API requests monthly, and you won’t need to provide a credit card to access the free trial.

29. Xverify

A powerful API for real-time email address verification, the service helps to convert leads to sales with the help of email address verification. The service also boasts high accuracy and helps to attain a very high deliverability rate. You can test the service for free by just signing up, while the charges for email verification can be as low as $ 0.0009 per email depending on the package you choose.

30. ZeroBounce Email Verification API

ZeroBounce helps to clean email lists and improve the deliverability of your email program. The service performs verifications quickly and promises high accuracy with a focus on security. You can try the service with 100 free monthly email verifications.

Wrapping Up

Email validation and verification services help to improve your email campaigns by removing bad email addresses from your database and increasing deliverability. Most API services mentioned in this article also provide real-time verification, making the service essential to improving the reputation of your mail servers.