# WarmySender, free: Email verification API

> Every plan includes real-time email verification, so a list is cleaned before it is ever sent to. Verify a single address or upload a list, and each address comes back Valid, Risky, Invalid or Unknown — Unknown results are always free.

WarmySender's email verification API on its Free daily check 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 WarmySender scores 69.3 out of 100. WarmySender ranks 12th of 197 providers.
This plan is free. We rank 3,886 plans for email verification APIs by price. Half the plans cost $1.998 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.
[pingutil](https://datacircle.dev/validate-email-apis/pingutil/free-api-key-post-v1-verify/llms.txt), [MailTester Ninja](https://datacircle.dev/validate-email-apis/mailtester-ninja/23-99-monthly/llms.txt) and [Giggal](https://datacircle.dev/validate-email-apis/giggal/39-pack-50000-credits-post-v1-verify/llms.txt) are the best email verification API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-email-apis/warmysender/free
- [Email validation API: 190+ verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://warmysender.com/email-verifier?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `POST https://warmysender.com/api/v1/verification/verify`
- API key: with the plan, on https://warmysender.com/email-verifier?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Its API docs: https://warmysender.com/docs/integrations?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: WarmySender (https://warmysender.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-05

## 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: nothing else

## Overage

- Units cap: hard

## Not found

- $ per 1,000: $0.00

## Catch-all

- $ per 1,000: $0.00

## In their words

- Their pitch: Every plan includes real-time email verification, so a list is cleaned before it is ever sent to. Verify a single address or upload a list, and each address comes back Valid, Risky, Invalid or Unknown — Unknown results are always free.

## Data

- Freshness: live
- What it checks: mail servers, mailbox
- Keep data: no API terms
- Use data: no API terms

## Plan

- Pay: $0
- You get: 1 credit a day
- Enough for: 1 call a day
- Expires: end of each day, no carry over

## Rate limit

- Per day: 1
- Per second: 0.33
- Batch: 1

## Speed

- Answer: in the call
- Median: 1.65 s

## The call

- You send: email. Optional: Idempotency-Key header
- Method: POST
- Path: /verification/verify

## About the plan

- Plan: Free daily check
- Who can get it: anyone

## The 6 fields the plan's answer can hold

email address, status, reason, catch-all, MX host, request ID

## WarmySender's plans (17)

- [WarmySender, free](https://datacircle.dev/validate-email-apis/warmysender/free/llms.txt): $0.00 per 1,000, 33% complete, live
- [WarmySender, $29 pack, 15,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/29-pack-15000-verification-credits-post-verification-verify/llms.txt): $1.933 per 1,000, 33% complete, live
- [WarmySender, $79 pack, 100,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/79-pack-100000-verification-credits-post-verification-verify/llms.txt): $0.79 per 1,000, 33% complete, live
- [WarmySender, $158 pack, 220,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/158-pack-220000-verification-credits-post-verification-verify/llms.txt): $0.718 per 1,000, 33% complete, live
- [WarmySender, $237 pack, 360,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/237-pack-360000-verification-credits-post-verification-verify/llms.txt): $0.658 per 1,000, 33% complete, live
- [WarmySender, $316 pack, 520,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/316-pack-520000-verification-credits-post-verification-verify/llms.txt): $0.608 per 1,000, 33% complete, live
- [WarmySender, $395 pack, 700,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/395-pack-700000-verification-credits-post-verification-verify/llms.txt): $0.564 per 1,000, 33% complete, live
- [WarmySender, $499 pack, 1,000,000 verification credits, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/499-pack-1000000-verification-credits-post-verification-verify/llms.txt): $0.499 per 1,000, 33% complete, live
- [WarmySender, $19 monthly, Pro Monthly, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/19-monthly-pro-monthly-post-verification-verify/llms.txt): $19.192 per 1,000, 33% complete, live
- [WarmySender, $69.99 monthly, Enterprise Monthly, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/69-99-monthly-enterprise-monthly-post-verification-verify/llms.txt): $2.333 per 1,000, 33% complete, live
- [WarmySender, $199 monthly, Ultimate Monthly, POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/199-monthly-ultimate-monthly-post-verification-verify/llms.txt): $3.317 per 1,000, 33% complete, live
- [WarmySender, $102.60 yearly, Pro Annual (55% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/102-60-yearly-pro-annual-55-off-post-verification-verify/llms.txt): $8.636 per 1,000, 33% complete, live
- [WarmySender, $205.20 yearly, Pro 3-Year (70% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/205-20-yearly-pro-3-year-70-off-post-verification-verify/llms.txt): $5.758 per 1,000, 33% complete, live
- [WarmySender, $377.88 yearly, Enterprise Annual (55% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/377-88-yearly-enterprise-annual-55-off-post-verification-verify/llms.txt): $1.05 per 1,000, 33% complete, live
- [WarmySender, $756 yearly, Enterprise 3-Year (70% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/756-yearly-enterprise-3-year-70-off-post-verification-verify/llms.txt): $0.70 per 1,000, 33% complete, live
- [WarmySender, $1,074.60 yearly, Ultimate Annual (55% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/1074-60-yearly-ultimate-annual-55-off-post-verification-verify/llms.txt): $1.492 per 1,000, 33% complete, live
- [WarmySender, $2,149.20 yearly, Ultimate 3-Year (70% off), POST /verification/verify](https://datacircle.dev/validate-email-apis/warmysender/2149-20-yearly-ultimate-3-year-70-off-post-verification-verify/llms.txt): $0.995 per 1,000, 33% complete, live

## WarmySender's calls (2)

- `POST /verification/verify`: [WarmySender, free](https://datacircle.dev/validate-email-apis/warmysender/free/llms.txt)
- `POST /verification/batches`: [WarmySender, $29 pack, 15,000 verification credits, POST /verification/batches](https://datacircle.dev/validate-email-apis/warmysender/29-pack-15000-verification-credits-post-verification-batches/llms.txt)

## WarmySender's APIs (1)

- [WarmySender: email verification API pricing, 17 plans](https://datacircle.dev/validate-email-apis/warmysender/free/llms.txt)

## WarmySender: email verification API alternatives

- [Bounceless, $499 monthly, Scale: 1,000,000 credits per month, POST /v1/requests, Create a batch (emails)](https://datacircle.dev/validate-email-apis/bounceless/499-monthly-scale-1000000-credits-per-month-post-v1-requests-1000000-credits-a-month/llms.txt): $0.499 per 1,000, 50% complete, live
- [MailTester, $499 pack](https://datacircle.dev/validate-email-apis/mailtester/499-pack/llms.txt): $0.499 per 1,000, 50% complete, live
- [VeriMails, $499 pack, 1,000,000 credits, POST /api/verify/single](https://datacircle.dev/validate-email-apis/verimails/499-pack-1000000-credits-post-api-verify-single/llms.txt): $0.499 per 1,000, 67% complete, live
- [EmailMarker, $999 pack, 2,000,000 credits, POST /api/upload](https://datacircle.dev/validate-email-apis/emailmarker/999-pack-2000000-credits-post-api-upload/llms.txt): $0.50 per 1,000, 17% complete, live

## 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://warmysender.com/api/v1/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/docs/integrations?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/documentation/email-verification-credits-and-daily-limits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/documentation/email-verification-limits-and-credits?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/email-verifier?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/mcp?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://warmysender.com/pricing?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing