# fourzerotwo, free: Email verification API

> Email syntax, whether the domain accepts mail, disposable and role-account flags.

fourzerotwo's Free key plan for the email verification API costs $0.00 per 1,000 emails. We check each provider's docs for 6 fields. fourzerotwo's docs list 2: Deliverability, Company.
You get up to 15,000 calls a month.
We ran fourzerotwo in [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt). We didn't score any fourzerotwo plan.
This plan is free. We rank 4,468 plans for email verification APIs by price. Half the plans cost $2.00 or less per 1,000 emails. [See the best free email verification API plan.](https://datacircle.dev/best-email-verification-api.txt)
[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. Disify's $9 monthly plan 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/fourzerotwo/free
- [Email validation API: best verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://fourzerotwo.si/free?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `GET https://fourzerotwo.si/v1/validators/email`
- API key: with the plan, on https://fourzerotwo.si/free?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Its API docs: https://fourzerotwo.si/apis/validators/email?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: fourzerotwo (https://fourzerotwo.si?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-10

## In the answer

- Completeness: 33%
- Deliverability: ✓
- Company: ✓

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: 529 other fourzerotwo calls: 500 a day

## Not found

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

## In their words

- Their pitch: Email syntax, whether the domain accepts mail, disposable and role-account flags.

## Data

- What it checks: format, mail servers, disposable domains, role addresses
- Keep data: no API terms
- Use data: Keep the attribution when you show the data.

## Plan

- Pay: $0
- Enough for: 15,000 calls a month

## Rate limit

- Per day: 500
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: email
- Method: GET
- Path: /v1/validators/email

## About the plan

- Plan: Free key
- Who can get it: anyone with an email address

## The 4 fields the plan's answer can hold

syntax valid, domain accepts mail, disposable, role account

## fourzerotwo's plans (5)

- [fourzerotwo, free](https://datacircle.dev/validate-email-apis/fourzerotwo/free/llms.txt): $0.00 per 1,000, 33% complete
- [fourzerotwo, pay as you go](https://datacircle.dev/validate-email-apis/fourzerotwo/pay-as-you-go/llms.txt): $1.00 per 1,000, 33% complete
- [fourzerotwo, $5 pack](https://datacircle.dev/validate-email-apis/fourzerotwo/5-pack/llms.txt): $1.00 per 1,000, 33% complete
- [fourzerotwo, $20 pack](https://datacircle.dev/validate-email-apis/fourzerotwo/20-pack/llms.txt): $1.00 per 1,000, 33% complete
- [fourzerotwo, $50 pack](https://datacircle.dev/validate-email-apis/fourzerotwo/50-pack/llms.txt): $1.00 per 1,000, 33% complete

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

- `GET /v1/validators/email`: [fourzerotwo, free](https://datacircle.dev/validate-email-apis/fourzerotwo/free/llms.txt)

## fourzerotwo's APIs (8)

- [fourzerotwo: business verification API pricing, 5 plans](https://datacircle.dev/business-verification-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: company discovery API pricing, 5 plans](https://datacircle.dev/company-discovery-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: company enrichment API pricing, 5 plans](https://datacircle.dev/company-enrichment-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: domain WHOIS API pricing, 5 plans](https://datacircle.dev/domain-whois-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: email verification API pricing, 5 plans](https://datacircle.dev/validate-email-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: phone validation API pricing, 5 plans](https://datacircle.dev/validate-phone-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: web scraping API pricing, 5 plans](https://datacircle.dev/web-scraping-apis/fourzerotwo/free/llms.txt)
- [fourzerotwo: IP company lookup API pricing, 5 plans, GET /v1/ip-geolocation/batch](https://datacircle.dev/ip-company-lookup-apis/fourzerotwo/free-key-get-v1-ip-geolocation-batch/llms.txt)
- [fourzerotwo: IP company lookup API pricing, 5 plans, GET /v1/ip-geolocation/lookup](https://datacircle.dev/ip-company-lookup-apis/fourzerotwo/free-key-get-v1-ip-geolocation-lookup/llms.txt)
- [fourzerotwo: IP company lookup API pricing, 5 plans, GET /v1/domains/ip-owner](https://datacircle.dev/ip-company-lookup-apis/fourzerotwo/free-key-get-v1-domains-ip-owner/llms.txt)
- [fourzerotwo: IP company lookup API pricing, 5 plans, GET /v1/ip-geolocation/asn](https://datacircle.dev/ip-company-lookup-apis/fourzerotwo/free-key-get-v1-ip-geolocation-asn/llms.txt)

## fourzerotwo: email verification API alternatives

- [Prime Verifier, $200 pack, Pay-As-You-Go 200,000 credits, POST /v1/verify/single](https://datacircle.dev/validate-email-apis/prime-verifier/200-pack-pay-as-you-go-200000-credits-post-v1-verify-single/llms.txt): $1.00 per 1,000, 50% complete
- [BillionVerify, $20 pack, Starter, POST /verify/bulk](https://datacircle.dev/validate-email-apis/billionverify/20-pack-starter-post-verify-bulk/llms.txt): $1.00 per 1,000, 67% complete, live
- [MillionPhones, $100 monthly](https://datacircle.dev/validate-email-apis/millionphones/100-monthly/llms.txt): $1.00 per 1,000, 33% complete, live
- [DeBounce, top-up from $200, 200K credits, GET /v1/, Single email validation](https://datacircle.dev/validate-email-apis/debounce/top-up-from-200-200k-credits-get-v1/llms.txt): $1.00 per 1,000, 50% complete, live
- [Foundry, pay as you go](https://datacircle.dev/validate-email-apis/foundry/pay-as-you-go/llms.txt): $1.00 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 2026-11-10.

- https://fourzerotwo.si/apis/validators/email?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://fourzerotwo.si/catalog.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://fourzerotwo.si/credits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://fourzerotwo.si/free?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://fourzerotwo.si/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://fourzerotwo.si/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing