# uChecker, free, First 100 addresses free, POST /api/v1/validate/bulk: Email verification API

> uChecker checks whether a mailbox actually exists, working down through DNS/MX records, an SMTP connection and provider-specific behaviour. Every address gets one of three values: good if it accepts mail, bad if it does not, or unknown if it could not be determined.

uChecker's email verification API on its First 100 addresses 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 uChecker scores 55.0 out of 100. uChecker ranks 46th 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/uchecker/free-first-100-addresses-free-post-api-v1-validate-bulk
- [Email validation API: 180+ verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://uchecker.net/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing#tariffs
- Request: `POST https://api.uchecker.net/api/v1/validate/bulk`
- API key: with the plan, on https://uchecker.net/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing#tariffs
- Its API docs: https://uchecker.net/en/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing#validate-bulk
- Sold by: uChecker (https://uchecker.net?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-04

## In the answer

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

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Verify a single address

## Overage

- Units cap: hard

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: uChecker checks whether a mailbox actually exists, working down through DNS/MX records, an SMTP connection and provider-specific behaviour. Every address gets one of three values: good if it accepts mail, bad if it does not, or unknown if it could not be determined.

## Data

- Freshness: live
- What it checks: format, mail servers, mailbox
- Keep data: no limit
- Use data: The user agrees not to use the Service for sending spam, unlawful mailings, or any other actions contrary to applicable law (Terms of Service, 4), «Пользователю запрещается копировать, распространять, перепродавать, передавать третьим лицам или иным образом использовать материалы Сервиса без разрешения правообладателя» (User Agreement, 5.2)

## Plan

- Pay: ₽0
- You get: 100 credits
- Enough for: 100 results, once
- Expires: never

## Rate limit

- Concurrent: no limit
- Batch: 9,000,000

## Speed

- Answer: by polling or webhook

## The call

- You send: emails. Optional: webhook_url, idempotency_key, client_type
- Method: POST
- Path: /api/v1/validate/bulk

## About the plan

- Plan: First 100 addresses free
- Who can get it: anyone

## The 3 fields the plan's answer can hold

email address, status, server response

## uChecker's plans (11)

- [uChecker, free, First 100 addresses free, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/free-first-100-addresses-free-post-api-v1-validate-bulk/llms.txt): $0.00 per 1,000, 33% complete, live
- [uChecker, ₽200 pack, 1,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/200-pack-1000-addresses-post-api-v1-validate-bulk/llms.txt): $2.388 per 1,000, 33% complete, live
- [uChecker, ₽1,000 pack, 5,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/1000-pack-5000-addresses-post-api-v1-validate-bulk/llms.txt): $2.388 per 1,000, 33% complete, live
- [uChecker, ₽2,000 pack, 10,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/2000-pack-10000-addresses-post-api-v1-validate-bulk/llms.txt): $2.388 per 1,000, 33% complete, live
- [uChecker, ₽3,750 pack, 25,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/3750-pack-25000-addresses-post-api-v1-validate-bulk/llms.txt): $1.791 per 1,000, 33% complete, live
- [uChecker, ₽7,500 pack, 50,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/7500-pack-50000-addresses-post-api-v1-validate-bulk/llms.txt): $1.791 per 1,000, 33% complete, live
- [uChecker, ₽15,000 pack, 100,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/15000-pack-100000-addresses-post-api-v1-validate-bulk/llms.txt): $1.791 per 1,000, 33% complete, live
- [uChecker, ₽16,000 pack, 200,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/16000-pack-200000-addresses-post-api-v1-validate-bulk/llms.txt): $0.955 per 1,000, 33% complete, live
- [uChecker, ₽25,000 pack, 500,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/25000-pack-500000-addresses-post-api-v1-validate-bulk/llms.txt): $0.597 per 1,000, 33% complete, live
- [uChecker, ₽37,500 pack, 750,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/37500-pack-750000-addresses-post-api-v1-validate-bulk/llms.txt): $0.597 per 1,000, 33% complete, live
- [uChecker, ₽50,000 pack, 1,000,000 addresses, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/50000-pack-1000000-addresses-post-api-v1-validate-bulk/llms.txt): $0.597 per 1,000, 33% complete, live

## uChecker's calls (2)

- `POST /api/v1/validate/bulk`: [uChecker, free, First 100 addresses free, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/free-first-100-addresses-free-post-api-v1-validate-bulk/llms.txt)
- `POST /api/v1/validate/single`: [uChecker, free, First 100 addresses free, POST /api/v1/validate/single](https://datacircle.dev/validate-email-apis/uchecker/free-first-100-addresses-free-post-api-v1-validate-single/llms.txt)

## uChecker's APIs (1)

- [uChecker: email verification API pricing, 11 plans, POST /api/v1/validate/bulk](https://datacircle.dev/validate-email-apis/uchecker/free-first-100-addresses-free-post-api-v1-validate-bulk/llms.txt)

## uChecker: email verification API alternatives

- [KaijuVerifier, $149 monthly, Scale, POST /api/v1/verify-single, Verify a single email with the SMTP probe (authenticated)](https://datacircle.dev/validate-email-apis/kaijuverifier/149-monthly-scale-post-api-v1-verify-single/llms.txt): $0.596 per 1,000, 50% complete, live
- [DeBounce, $1,196 monthly, 2M credits, Monthly, GET /v1/, Single email validation](https://datacircle.dev/validate-email-apis/debounce/1196-monthly-2m-credits-monthly-get-v1/llms.txt): $0.598 per 1,000, 50% complete, live
- [Bouncify, $299 monthly](https://datacircle.dev/validate-email-apis/bouncify/299-monthly/llms.txt): $0.598 per 1,000, 50% complete, live
- [Invalid Bounce, $299 pack](https://datacircle.dev/validate-email-apis/invalid-bounce/299-pack/llms.txt): $0.598 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 2026-11-04.

- https://api.uchecker.net/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/en?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/en/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/en/terms-of-service?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/polzovatelskoe-soglashenie?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://uchecker.net/publichnaja-oferta?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing