# Kaidn, free: Email verification API

> Disposable-domain, MX and address-integrity checks for one address.

Kaidn's Free plan for the email verification API costs $0.00 per 1,000 emails. We check each provider's docs for 6 fields. Kaidn's docs list 2: Address, Deliverability.
We ran Kaidn in [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt). We didn't score any Kaidn plan.
This plan is free. We rank 4,767 plans for email verification APIs by price. Half the plans cost $2.00 or less per 1,000 emails. [728 email verification API plans on our price sheet are free.](https://datacircle.dev/best-email-verification-api.txt) [pingutil's free plan](https://datacircle.dev/validate-email-apis/pingutil/free-api-key-post-v1-verify/llms.txt) scores highest of the free plans in our benchmark, at 82.3 out of 100.
[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. [StableEnrich's pay-as-you-go plan](https://datacircle.dev/validate-email-apis/stableenrich/pay-as-you-go-pay-per-request-with-x402-or-mpp-post-api-minerva-validate-emails/llms.txt) costs the least for 10,000 emails a month: $0.05.
[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, and costs less up front than treg's top-up from $10.
[Validemail.co](https://datacircle.dev/validate-email-apis/validemail-co/9-90-monthly-9-90-month-get-api-v1-validate/llms.txt), [pingutil](https://datacircle.dev/validate-email-apis/pingutil/free-api-key-post-v1-verify/llms.txt) and [looot](https://datacircle.dev/validate-email-apis/looot/top-up/llms.txt) are the best email verification API providers in the Datacircle benchmark.

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

## In the answer

- Completeness: 33%
- Address: ✓
- Deliverability: ✓

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Check an IP address · Check a phone number · Score an event · Score many events at once

## Not found

- $ per 1,000 calls that find nothing: $0.00

## In their words

- Their pitch: Disposable-domain, MX and address-integrity checks for one address.

## Data

- What it checks: format, mail servers, disposable domains
- Keep data: no limit
- Use data: You agree not to, and not to permit any third party to: use the Service unlawfully, or in violation of any applicable law, regulation, sanctions regime or third-party right, submit data you do not have a lawful basis and the necessary rights, consents or notices to submit and have processed (see section 7), use the Service as the sole or automated basis for a decision that produces legal or similarly significant effects on an individual, or to unlawfully discriminate against any person or group, including on the basis of a protected characteristic, use the Service for credit scoring, employment, insurance, housing, or any use regulated as a consumer report or background-screening service, unless you have separately arranged this with us in writing, attempt to reverse engineer, resell, sublicense, or build a competing risk-scoring product from the Service or its outputs, probe, scan, overload, circumvent rate limits, or interfere with the integrity or performance of the Service, upload malware, or use the Service to harass, defame, or harm others.

## Plan

- Pay: $0
- You get: 10,000 requests a month
- Enough for: 10,000 calls a month

## Rate limit

- Per second: 4
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: email
- Method: POST
- Path: /v1/check/email

## About the plan

- Plan: Free
- Who can get it: anyone

## The 16 fields the plan's answer can hold

fraud score, disposable, MX record, catch-all, gibberish, plus tag, canonical address, aliased, alias tricks, malformed, reject reason, recent abuse, network risk, network operators, honeypot hits, summary

## Kaidn's plans (5)

- [Kaidn, free](https://datacircle.dev/validate-email-apis/kaidn/free/llms.txt): $0.00 per 1,000, 33% complete
- [Kaidn, $39 monthly](https://datacircle.dev/validate-email-apis/kaidn/39-monthly/llms.txt): $0.78 per 1,000, 33% complete
- [Kaidn, $99 monthly](https://datacircle.dev/validate-email-apis/kaidn/99-monthly/llms.txt): $0.396 per 1,000, 33% complete
- [Kaidn, $299 monthly](https://datacircle.dev/validate-email-apis/kaidn/299-monthly/llms.txt): $0.299 per 1,000, 33% complete
- [Kaidn, contact us](https://datacircle.dev/validate-email-apis/kaidn/contact-us/llms.txt): 33% complete

## Kaidn's calls for this API (1)

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

## Kaidn's APIs (2)

- [Kaidn Email verification API pricing, 5 plans](https://datacircle.dev/validate-email-apis/kaidn/free/llms.txt)
- [Kaidn Phone validation API pricing, 5 plans](https://datacircle.dev/validate-phone-apis/kaidn/free/llms.txt)

## Kaidn: email verification API alternatives

[Kaidn alternatives: other email verification API providers by price](https://datacircle.dev/kaidn-alternatives.txt)

We list Kaidn's cheapest paid plan first. Next we list other providers' plans closest to Kaidn in price per 1,000 emails.

- [Kaidn, $299 monthly](https://datacircle.dev/validate-email-apis/kaidn/299-monthly/llms.txt): $0.299 per 1,000, 33% complete
- [Verimail, $299 monthly](https://datacircle.dev/validate-email-apis/verimail/299-monthly/llms.txt): $0.299 per 1,000, 50% complete, live
- [MailVeri, $299 pack, 1,000,000 credits, POST /verify-mail/](https://datacircle.dev/validate-email-apis/mailveri/299-pack-1000000-credits-post-verify-mail/llms.txt): $0.299 per 1,000, 50% complete, live
- [SendBridge, $299 pack](https://datacircle.dev/validate-email-apis/sendbridge/299-pack/llms.txt): $0.299 per 1,000, 50% complete
- [Consulti.ai, $299 pack](https://datacircle.dev/validate-email-apis/consulti-ai/299-pack/llms.txt): $0.299 per 1,000, 33% 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 2026-11-11.

- https://api.kaidn.io/v1/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://kaidn.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://kaidn.io/docs/api?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://kaidn.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://kaidn.io/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://kaidn.io/tools/email-lookup?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing