# Check Harbor, free: Email verification API

> Production-ready email, phone, and IP validation API. Start free with 1,000 credits/month — no credit card required.

Check Harbor's email verification API on its Free plan. It costs $0.00 per 1,000 emails. It returns 2 of the 6 key fields we check: Deliverability, Confidence.
We haven't run Check Harbor through [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt) yet.
This plan is free. We rank 3,753 plans for email verification APIs by price. Half the plans cost $1.98 per 1,000 emails or less.
[treg's top-up from $10](https://datacircle.dev/validate-email-apis/treg/top-up-from-10/llms.txt) is the cheapest paid plan per 1,000 emails: $0.00 on average. treg asks one provider after another until one answers. You pay $68.365 per 1,000 emails when no provider answers.
[Disify's $9 monthly plan (/email)](https://datacircle.dev/validate-email-apis/disify/9-monthly-starter-post-email/llms.txt) covers any number of emails. Disify's $9 monthly plan costs less up front than treg's top-up from $10.
[MailTester Ninja](https://datacircle.dev/validate-email-apis/mailtester-ninja/23-99-monthly/llms.txt), [Enrich.so](https://datacircle.dev/validate-email-apis/enrich-so/499-monthly/llms.txt) and [GetProspect](https://datacircle.dev/validate-email-apis/getprospect/369-pack/llms.txt) are the best email verification API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-email-apis/check-harbor/free
- [Email validation API: 180+ verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://checkharbor.pages.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `POST https://api.checkharbor.com/v1/email/validate`
- API key: with the plan, on https://checkharbor.pages.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Its API docs: https://checkharbor.pages.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: Check Harbor (https://checkharbor.pages.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-02

## In the answer

- Completeness: 33%
- Deliverability: ✓
- Confidence: ✓

## Price

- $ per 1,000 emails: $0.00
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: IP intelligence · Phone validation

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Production-ready email, phone, and IP validation API. Start free with 1,000 credits/month — no credit card required.

## Data

- Keep data: no limit
- Use data: You agree to use the Service only for lawful, legitimate purposes — such as cleaning signup data, improving deliverability, and preventing fraud and abuse. You must not use the Service to: send unsolicited bulk messages (spam), harass, or stalk any person, enable fraud, identity theft, or any unlawful activity, validate data you have no lawful basis to process, or violate any applicable privacy law (including GDPR or KVKK) with respect to the data you submit, attempt to reverse engineer, resell, or rebrand the Service as your own competing validation product, circumvent rate limits, credit metering, or security controls

## Plan

- Pay: $0
- You get: 1,000 credits a month

## Rate limit

- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: email, content-type header "application/json"
- Method: POST
- Path: /v1/email/validate

## About the plan

- Plan: Free
- Who can get it: anyone

## The 3 fields the plan's answer can hold

valid syntax, deliverability, score

## Check Harbor's plans (7)

- [Check Harbor, free](https://datacircle.dev/validate-email-apis/check-harbor/free/llms.txt): $0.00 per 1,000, 33% complete
- [Check Harbor, $9 pack](https://datacircle.dev/validate-email-apis/check-harbor/9-pack/llms.txt): 33% complete
- [Check Harbor, $49 pack](https://datacircle.dev/validate-email-apis/check-harbor/49-pack/llms.txt): 33% complete
- [Check Harbor, $199 pack](https://datacircle.dev/validate-email-apis/check-harbor/199-pack/llms.txt): 33% complete
- [Check Harbor, $29 monthly](https://datacircle.dev/validate-email-apis/check-harbor/29-monthly/llms.txt): 33% complete
- [Check Harbor, $99 monthly](https://datacircle.dev/validate-email-apis/check-harbor/99-monthly/llms.txt): 33% complete
- [Check Harbor, $299 monthly](https://datacircle.dev/validate-email-apis/check-harbor/299-monthly/llms.txt): 33% complete

## Check Harbor's calls (1)

- `POST /v1/email/validate`: [Check Harbor, free](https://datacircle.dev/validate-email-apis/check-harbor/free/llms.txt)

## Check Harbor's APIs (1)

- [Check Harbor: email verification API pricing, 7 plans](https://datacircle.dev/validate-email-apis/check-harbor/free/llms.txt)

## Check Harbor: email verification API alternatives

- [MailTester Ninja, free, No token](https://datacircle.dev/validate-email-apis/mailtester-ninja/free-no-token/llms.txt): $0.00 per 1,000, 50% complete, live
- [Enrich.so, free, POST /email-validation](https://datacircle.dev/validate-email-apis/enrich-so/free/llms.txt): $0.00 per 1,000, 50% complete, live
- [GetProspect, free, POST /v2/email-verifications](https://datacircle.dev/validate-email-apis/getprospect/free-free-post-v2-email-verifications/llms.txt): $0.00 per 1,000, 50% complete, live
- [Prime Verifier, free, POST /v1/verify/single](https://datacircle.dev/validate-email-apis/prime-verifier/free-post-v1-verify-single/llms.txt): $0.00 per 1,000, 50% complete
- [A-Leads, free](https://datacircle.dev/validate-email-apis/a-leads/free/llms.txt): $0.00 per 1,000, 50% complete

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-02.

- https://checkharbor.pages.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://checkharbor.pages.dev/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing