# ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses, quick check: Email verification API

> Use it to clean a signup form or a large list cheaply, then run a full check on what you will send to.

ProspectAPIs'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, Confidence.
The cheapest of the 1,776 plans we rank by price is [treg, top-up from $10](https://datacircle.dev/validate-email-apis/treg/top-up-from-10/llms.txt). treg asks one provider after another until one answers. treg costs $0.00 per 1,000 emails on average. You pay $26.95 per 1,000 emails when no provider answers.

- This page: https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses-quick-check
- [Best email verification API in 2026](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://prospectapis.com/pricing
- Its API docs: https://prospectapis.com/docs/reference/verify-emails
- Sold by: ProspectAPIs (https://prospectapis.com)
- Checked: 2026-10-26

## In the answer

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

## Price

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

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Search funding rounds · Read one funding round · Create a watchlist · Start a research brief · Clean a list · Start a verification job · Find an email address

## Not found

- $ per 1,000: $0.00

## Catch-all

- $ per 1,000: $0.00

## In their words

- Their pitch: Use it to clean a signup form or a large list cheaply, then run a full check on what you will send to.

## Data

- Keep data: no limit
- Use data: Check anything that matters before you rely on it, and do not use the service as the only basis for a decision with legal or similar effect on a person. You may use what the API returns inside your own products and workflows. You may not resell or republish the data as a substantially similar dataset or API. [...] Use of the service must follow the acceptable use policy. [...] This policy sets the limits on how the service and its output may be used. [...] Use it for: Researching companies and the people who publicly represent them in a business role. Preparing for sales calls and writing outreach that is relevant to the recipient. Account research, territory planning and enriching business records with funding history. Do not use it to: Profile private individuals, or research anyone outside a business context. Harass, stalk, threaten or discriminate against anyone. Send messages that break anti-spam or marketing consent laws where the recipient is. Make decisions about employment, credit, insurance or housing for an individual. Resell or republish the data as a substantially similar dataset or API. Share API keys between unrelated parties, or create accounts to multiply free records. Probe, overload or work around the rate limits, billing or security of the service. Send the research API inputs you have no right to share, such as confidential third-party data in context.

## Plan

- Pay: $0
- You get: $1
- Enough for: 1,000 results, once
- Expires: never

## Rate limit

- Per second: 1
- Batch: 25

## Speed

- Answer: in the call

## The call

- You send: emails, depth "quick". Optional: emails[].first_name, emails[].last_name, Idempotency-Key
- Method: POST
- Path: /v1/email/verify

## About the plan

- Plan: Free
- Who can get it: anyone, one account per person or company

## The 17 fields the plan's answer can hold

email address, status, reason, reason text, score, recommendation, charged, flags, SMTP code, catch-all tier, did you mean, mail provider, checked at, cache age days, results count, charged count, amount (USD)

## ProspectAPIs's plans (5)

- [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt): $0.00 per 1,000, 50% complete
- [ProspectAPIs, top-up from $10, Credit pack, any amount from $10 to $10,000, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-10-credit-pack-any-amount-from-10-to-10000-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt): $1.00 per 1,000, 50% complete
- [ProspectAPIs, top-up from $100, Top-up of $100 or more, +25% bonus credit, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-100-top-up-of-100-or-more-25-bonus-credit-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt): $0.80 per 1,000, 50% complete
- [ProspectAPIs, top-up from $500, Top-up of $500 or more, +60% bonus credit, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-500-top-up-of-500-or-more-60-bonus-credit-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt): $0.625 per 1,000, 50% complete
- [ProspectAPIs, top-up from $2,000, Top-up of $2,000 or more, +120% bonus credit, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-2000-top-up-of-2000-or-more-120-bonus-credit-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt): $0.455 per 1,000, 50% complete

## ProspectAPIs's calls for this API (4)

- `POST /v1/email/clean`: [ProspectAPIs, free, Free, POST /v1/email/clean](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-clean/llms.txt)
- `POST /v1/email/verify/jobs`: [ProspectAPIs, free, Free, POST /v1/email/verify/jobs](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-jobs/llms.txt)
- `POST /v1/email/verify`, Verify email addresses: [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses/llms.txt)
- `POST /v1/email/verify`, Verify email addresses, quick check: [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt)

## ProspectAPIs's APIs (4)

- [ProspectAPIs: company enrichment API pricing, 5 plans](https://datacircle.dev/company-enrichment-apis/prospectapis/free/llms.txt)
- [ProspectAPIs: email finder API pricing, 5 plans](https://datacircle.dev/find-email-apis/prospectapis/free/llms.txt)
- [ProspectAPIs: email verification API pricing, 5 plans, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, POST /v1/watchlists](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-post-v1-watchlists/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, GET /v1/funding/:id](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-get-v1-funding-id/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, GET /v1/funding](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-get-v1-funding/llms.txt)

## ProspectAPIs: email verification API alternatives

- [MillionVerifier, $449 pack, 1,000,000 verification credits, GET /api/v3](https://datacircle.dev/validate-email-apis/millionverifier/449-pack-1000000-verification-credits-get-api-v3/llms.txt): $0.449 per 1,000, 50% complete, live
- [Icypeas, $2,245.50 monthly, Hypergrowth, 500,000 credits a month, POST /email-verification](https://datacircle.dev/validate-email-apis/icypeas/2245-50-monthly-hypergrowth-500000-credits-a-month-post-email-verification/llms.txt): $0.449 per 1,000, 33% complete
- [Captain Verify, €2,000 pack, 5,000,000 Email Verifications, on demand, POST /file/email](https://datacircle.dev/validate-email-apis/captain-verify/2000-pack-5000000-email-verifications-on-demand-post-file-email/llms.txt): $0.45 per 1,000, 33% complete, live
- [Bounceless, $1,149 pack, 2,500,000 credit pack, POST /v1/requests, Create a batch (emails)](https://datacircle.dev/validate-email-apis/bounceless/1149-pack-2500000-credit-pack-post-v1-requests-2500000-credits/llms.txt): $0.46 per 1,000, 50% 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 2026-10-26.

- https://prospectapis.com
- https://prospectapis.com/acceptable-use
- https://prospectapis.com/docs/email-verification
- https://prospectapis.com/docs/rate-limits
- https://prospectapis.com/docs/reference/verify-emails
- https://prospectapis.com/pricing
- https://prospectapis.com/terms