# IsValid, free: Email verification API

> Validates email addresses. Checks RFC 5322 format compliance, domain structure, and optionally verifies that the domain has valid MX records.

IsValid's email verification API on its Free plan. It costs $0.00 per 1,000 emails. It returns 3 of the 6 key fields we check: Address, Deliverability, Company.
We ran IsValid in [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt). We didn't score any IsValid plan.
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/isvalid/free
- [Email validation API: 180+ verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://isvalid.dev/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `GET https://api.isvalid.dev/v0/email`
- API key: with the plan, on https://isvalid.dev/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Its API docs: https://isvalid.dev/docs/email?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: IsValid (https://isvalid.dev?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-05

## In the answer

- Completeness: 50%
- Address: ✓
- Deliverability: ✓
- Company: ✓

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: 76 other calls

## Overage

- Units cap: hard

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Validates email addresses. Checks RFC 5322 format compliance, domain structure, and optionally verifies that the domain has valid MX records.

## Data

- What it checks: format, mail servers
- Keep data: no limit
- Use data: You agree to use the Service strictly within the limits of your chosen subscription plan. [...] You must not attempt to circumvent rate limits through any means, including but not limited to: Creating multiple accounts to aggregate free-tier quotas, Using proxies, VPNs, or other technical measures to bypass rate limiting, Sharing API keys with third parties outside your organization, Reverse engineering or scraping the Service infrastructure [...] Abusive use of the Service is strictly prohibited. [...] if we determine in our sole discretion that you are engaged in: Automated abuse — running bots, scrapers, or scripts that place excessive load on the Service beyond normal API usage patterns, Fraudulent activity — using the Service to validate data for purposes of fraud, identity theft, spam, or phishing, Illegal use — any activity that violates applicable local, national, or international law, Reselling without authorization — offering the Service to third parties as your own product without a written reseller agreement, Security attacks — attempting to probe, scan, or test vulnerabilities of the Service or its underlying infrastructure

## Plan

- Pay: €0
- You get: 100 requests a day
- Enough for: 100 calls a day
- Expires: Rate limits reset at midnight UTC each day

## Rate limit

- Per day: 100
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: value. Optional: checkMx
- Method: GET
- Path: /v0/email

## About the plan

- Plan: Free
- Who can get it: anyone

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

valid, local part, domain, MX valid

## IsValid's plans (3)

- [IsValid, free](https://datacircle.dev/validate-email-apis/isvalid/free/llms.txt): $0.00 per 1,000, 50% complete
- [IsValid, €9 monthly](https://datacircle.dev/validate-email-apis/isvalid/9-monthly/llms.txt): $0.034 per 1,000, 50% complete
- [IsValid, €49 monthly](https://datacircle.dev/validate-email-apis/isvalid/49-monthly/llms.txt): $0.018 per 1,000, 50% complete

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

- `GET /v0/email`: [IsValid, free](https://datacircle.dev/validate-email-apis/isvalid/free/llms.txt)

## IsValid's APIs (3)

- [IsValid: email verification API pricing, 3 plans](https://datacircle.dev/validate-email-apis/isvalid/free/llms.txt)
- [IsValid: phone validation API pricing, 3 plans](https://datacircle.dev/validate-phone-apis/isvalid/free/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/au/abn](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-au-abn/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/pl/ceidg](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-pl-ceidg/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/br/cnpj](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-br-cnpj/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/duns](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-duns/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/eori](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-eori/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/pl/krs](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-pl-krs/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/lei](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-lei/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/lei/search](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-lei-search/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/pl/regon](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-pl-regon/llms.txt)
- [IsValid: business verification API pricing, 3 plans, GET /v0/vat](https://datacircle.dev/business-verification-apis/isvalid/free-get-v0-vat/llms.txt)

## IsValid: email verification API alternatives

- [Pushbuild, free](https://datacircle.dev/validate-email-apis/pushbuild/free/llms.txt): $0.00 per 1,000, 50% complete
- [Neutrino API, $50 monthly, Tier 2, GET /email-validate](https://datacircle.dev/validate-email-apis/neutrino-api/50-monthly-tier-2-get-email-validate/llms.txt): $0.017 per 1,000, 50% complete, stored
- [GMass, $59.95 monthly](https://datacircle.dev/validate-email-apis/gmass/59-95-monthly/llms.txt): $0.017 per 1,000, 33% complete, live
- [EnvoAPI, $49 monthly, Launch, GET /v1/emails/disposable](https://datacircle.dev/validate-email-apis/envoapi/49-monthly-launch-get-v1-emails-disposable/llms.txt): $0.019 per 1,000, 33% complete, stored
- [API Ninjas, $2,388 yearly](https://datacircle.dev/validate-email-apis/api-ninjas/2388-yearly/llms.txt): $0.02 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 2026-11-05.

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