Verifier API alternatives
Verifies that a given email is real. If it doesn't fit your project, here are the 10 best free Email APIs to use instead in 2026, out of 36 in the directory.
For reference, Verifier API: Callable from the browser (CORS) · HTTPS.
- 1
Kickbox API
Online · 1026 msEmail verification API. A free email API by Powered by Kickbox.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 2

mail.gw API
Online · 546 msAPI for creating temporary email accounts.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 3
mail.tm API
Online · 454 msTemporary Email Service. A free email API by Mail.tm.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 4

MailSenpai DNS Check API
Online · 805 msCheck a domain's SPF, DKIM, DMARC and MX records and get what to fix, with the values to publish.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 5
Cloudmersive Validate API
Online · 622 msValidate email addresses, phone numbers, VAT numbers and domain names.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 6
Email Validator by LifeStep API
Online · 1178 msValidate email syntax and MX, detect disposable/role addresses, suggest typo fixes.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS - 7

EmailJS API
Online · 505 msSend emails directly from client-side JavaScript without a backend server.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 8

Mailfornet API
Online · 788 msDisposable inboxes for end-to-end signup tests, with long-polling and HMAC-signed webhooks.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 9
SMTPfast API
Online · 783 msSend transactional email, manage contacts and broadcasts, free 3,000 emails/month.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 10

Disify API
Online · 1344 msValidate and detect disposable and temporary email addresses.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
Verifier API vs alternatives
| API | API key | HTTPS | CORS | Uptime | Response | Rating |
|---|---|---|---|---|---|---|
| Verifier | Required | Yes | Yes | Down | – | Not rated |
| No | Yes | Yes | Up | 1026 ms | Not rated | |
| No | Yes | Yes | Up | 546 ms | Not rated | |
| No | Yes | Yes | Up | 454 ms | Not rated | |
| No | Yes | Yes | Up | 805 ms | Not rated | |
| Required | Yes | Yes | Up | 622 ms | Not rated | |
| Email Validator by LifeStep | No | Yes | Yes | Up | 1178 ms | Not rated |
| Required | Yes | Yes | Up | 505 ms | Not rated | |
| Required | Yes | Yes | Up | 788 ms | Not rated |
See also: best Email APIs · all Email APIs
Verifier API alternatives FAQ
What is the best free alternative to the Verifier API in 2026?
The top-ranked free alternatives to the Verifier API are Kickbox API, mail.gw API and mail.tm API, all in the Email category. Rankings combine access (API key, HTTPS, CORS), daily uptime checks and developer ratings.
Is there a Verifier API alternative that doesn't need an API key?
Yes: Kickbox API, mail.gw API and mail.tm API work without an API key, unlike the Verifier API, which uses apiKey authentication.
How many Email APIs are similar to the Verifier API?
The directory lists 36 other free Email APIs. This page compares the top ones side by side.