# OpenLookup, free: Email verification API

> Email syntax, domain/MX, disposable, role, and free-provider signals.

OpenLookup'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: Address, Deliverability.
In [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt), the best plan from OpenLookup scores 0.0 out of 100. OpenLookup ranks 165th of 181 providers.
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/openlookup/free
- [Email validation API: 180+ verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://openlookup.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `POST https://openlookup.io/api/v1/email/check`
- API key: with the plan, on https://openlookup.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Its API docs: https://openlookup.io/docs/email?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: OpenLookup (https://openlookup.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-02

## 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: Phone Check · IP Check · Domain Check · IBAN Check · BIC Check · VAT Check · LEI Check · Card BIN Check · ISIN Check · Routing Number Check · Crypto Address Check · ASN Check · Security Headers Check · DNSSEC Check · CAA Check · TLS Check · Typosquat Check · Website Status Check · IPv6 Readiness Check · URL Safety Check · Batch check

## Overage

- Units cap: hard

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Email syntax, domain/MX, disposable, role, and free-provider signals.

## Data

- Freshness: stored
- What it checks: format, mail servers, disposable domains, role addresses
- Keep data: no limit
- Use data: You may not use OpenLookup to facilitate spam or robocalling, to launder or clean contact lists obtained without the consent of the people on them, or for any unlawful purpose. [...] The following uses are prohibited: Cleaning or validating email or phone number lists that were purchased, scraped, or otherwise obtained without the consent of the people on them, Preparing, testing, or supporting unsolicited bulk email (spam) or unsolicited robocall/ text campaigns, Attempting to enumerate, harvest, or reverse-engineer valid email addresses or phone numbers using the API's signals, Scanning or probing IP ranges or domains you do not own or operate for purposes beyond the risk-assessment use case the API is provided for, Reselling or rebranding API access without a written agreement with us, Any use that violates applicable law, including data protection law in your or your users' jurisdiction, Attempting to circumvent rate limits, credit limits, or authentication controls

## Plan

- Pay: $0
- You get: 100 requests a month
- Enough for: 100 calls a month

## Rate limit

- Per second: 0.17
- Batch: 1

## Speed

- Answer: in the call

## The call

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

## About the plan

- Plan: Free
- Who can get it: anyone

## The 13 fields the plan's answer can hold

email address, risk score, classification, recommendation, syntax valid, domain exists, MX found, disposable, role account, free provider, degraded, response time, credits remaining

## OpenLookup's plans (4)

- [OpenLookup, free](https://datacircle.dev/validate-email-apis/openlookup/free/llms.txt): $0.00 per 1,000, 33% complete, stored
- [OpenLookup, $9 monthly, Starter, POST /v1/email/check](https://datacircle.dev/validate-email-apis/openlookup/9-monthly-starter-post-v1-email-check/llms.txt): $1.80 per 1,000, 33% complete, stored
- [OpenLookup, $49 monthly, Pro, POST /v1/email/check](https://datacircle.dev/validate-email-apis/openlookup/49-monthly-pro-post-v1-email-check/llms.txt): $0.98 per 1,000, 33% complete, stored
- [OpenLookup, contact us, Business, POST /v1/email/check](https://datacircle.dev/validate-email-apis/openlookup/contact-us-business-post-v1-email-check/llms.txt): 33% complete, stored

## OpenLookup's calls for this API (2)

- `POST /v1/email/check`: [OpenLookup, free](https://datacircle.dev/validate-email-apis/openlookup/free/llms.txt)
- `POST /v1/email/check/batch`: [OpenLookup, $9 monthly, Starter, POST /v1/email/check/batch](https://datacircle.dev/validate-email-apis/openlookup/9-monthly-starter-post-v1-email-check-batch/llms.txt)

## OpenLookup's APIs (2)

- [OpenLookup: email verification API pricing, 4 plans](https://datacircle.dev/validate-email-apis/openlookup/free/llms.txt)
- [OpenLookup: phone validation API pricing, 4 plans](https://datacircle.dev/validate-phone-apis/openlookup/free/llms.txt)

## OpenLookup: email verification API alternatives

- [KaijuVerifier, $49 monthly, Growth, POST /api/v1/jobs, Submit an async bulk job](https://datacircle.dev/validate-email-apis/kaijuverifier/49-monthly-growth-post-api-v1-jobs-submit-an-async-bulk-job/llms.txt): $0.98 per 1,000, 50% complete, stored
- [Elastic Email, $49 monthly, Email API Pro (50,000 emails/month), POST /verifications/files](https://datacircle.dev/validate-email-apis/elastic-email/49-monthly-email-api-pro-50000-emails-month-post-verifications-files/llms.txt): $0.98 per 1,000, 50% complete, stored
- [IsItDisposable, $49 monthly, Growth, POST /v1/check](https://datacircle.dev/validate-email-apis/isitdisposable/49-monthly-growth-post-v1-check/llms.txt): $0.98 per 1,000, 50% complete, stored
- [NexMailPro, $49 pack, Volume Top-Up, POST /verify/email](https://datacircle.dev/validate-email-apis/nexmailpro/49-pack-volume-top-up-post-verify-email/llms.txt): $0.98 per 1,000, 50% complete, stored

## 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://openlookup.io?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/acceptable-use?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/docs/email?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/docs/phone?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/docs/rate-limits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://openlookup.io/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing