API review

MillionVerifier API review

Low-cost email verification: a simple real-time GET API plus a CSV bulk API, prepaid credits that never expire, and no charge for catch-all/unknown results (as a discretionary promotion). Best for cheapest bulk cleaning of large lists.

Verified 25 Oct 2026 · 8 endpoints listed

See pricing

MillionVerifier API docs

What a call costs

The actions you pay for, as MillionVerifier prices them in credits.

Action	Cost	Per
Verify good or bad email	1 credit	per email
Catch-all or unknown result	API: may not be deducted; bulk file: deducted, then re-credited as Promotional Credits (zero cash value). Discretionary goodwill programme, can be withdrawn without notice	per email
Million Ever Green promo	+1M free credits per 5M purchased (cumulative over past purchases)	promo
Auto top-up promo	+10% extra credits on every payment	promo

Pricing, plan by plan

US dollars, as MillionVerifier's pricing page shows them on 25 Oct 2026. Monthly and annual billing are shown apart.

Free tier 100 free verification credits on signup, no card required (homepage, re-checked live 2026-10-25); promotional credits per the terms

10,000 credits

One-off pack

10,000 credits one-off for $39 ($0.0039/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

25,000 credits

One-off pack

25,000 credits one-off for $59 ($0.00236/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

50,000 credits

One-off pack

50,000 credits one-off for $89 ($0.00178/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

100,000 credits

One-off pack

100,000 credits one-off for $149 ($0.00149/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

500,000 credits

One-off pack

500,000 credits one-off for $299 ($0.00059/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

1,000,000 credits

One-off pack

1,000,000 credits one-off for $449 ($0.00044/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

Show all 13 plansShow fewer plans

2,000,000 credits

One-off pack

2,000,000 credits one-off for $799 (~$0.00040/credit, computed)

API included

Plan details

credits never expire; volume pricing above 50M by request

3,000,000 credits

One-off pack

3,000,000 credits one-off for $1,099 (~$0.00037/credit, computed)

API included

Plan details

credits never expire; volume pricing above 50M by request

4,000,000 credits

One-off pack

4,000,000 credits one-off for $1,399 (~$0.00035/credit, computed)

API included

Plan details

credits never expire; volume pricing above 50M by request

5,000,000 credits

One-off pack

5,000,000 credits one-off for $1,599 ($0.00031/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

10,000,000 credits

One-off pack

10,000,000 credits one-off for $2,599 ($0.00025/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

25,000,000 credits

One-off pack

25,000,000 credits one-off for $4,999 ($0.00019/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

50,000,000 credits

One-off pack

50,000,000 credits one-off for $8,499 ($0.00016/credit)

API included

Plan details

credits never expire; volume pricing above 50M by request

Live re-check 2026-10-25 (plain Python, USD): the homepage slider's package table in /assets/js/main.js lists 13 one-off packages [credits, USD]; 10 appear on the slider, 2M/3M/4M only under 'See all packages'. All prices match the earlier headless capture. Promos from millionverifier.com/best-email-verification-prices.md; the terms treat all promotional credits (sign-up, auto top-up +10%, MillionEvergreen, risky-result) as discretionary with zero cash value.

How to get an API key

MillionVerifier uses API key. The steps below follow MillionVerifier's own docs.

Create a MillionVerifier account. API access starts on the 10,000 credits plan.
app.millionverifier.com/api; unlimited keys, each can be switched on/off, commented and IP-restricted (allow/deny list).
Send it with every request: query parameter: 'api' on the Single API, 'key' on the Bulk API.
Make a first call: Verify one email in real time. Keep the key in an environment variable, never in the command.
```
curl -X GET "https://api.millionverifier.com/api/v3/?api=$MILLIONVERIFIER_API_KEY"
```

Where the docs live

What	Where
Documentation	developer.millionverifier.com
API reference	developer.millionverifier.com
OpenAPI spec	developer.millionverifier.com
llms.txt	millionverifier.com/llms.txt
Base URL	`https://api.millionverifier.com`

Strengths and limits

Where it fits

Cheapest bulk cleaning of large lists (from $0.0039/credit at 10K down to $0.00016 at 50M)
Simple integrations: one GET call with api key + email
Lists heavy in catch-alls, since risky results are not billed (currently)

Where it falls short

Needing documented rate limits or SLAs (none published)
Webhook-driven pipelines (no callbacks; poll fileinfo)
AI-agent/MCP setups (no documented MCP server)

Worth knowing

The 'we don't charge for catch-all or unknown' promise is, per the Terms of Service (published 19 Oct 2026), a discretionary goodwill promotion that can be changed or withdrawn without updating the terms. On bulk files the credit is deducted first and a Promotional Credit (zero cash value) is added back; on the API the credit may simply not be deducted.
The 100% money-back guarantee (refund if hard bounces exceed 4%) covers files uploaded through the web app; API and one-by-one verifications are excluded (terms).
The terms let MillionVerifier demand evidence of a list's lawful source and pause processing or the API while reviewing.
Single API timeout defaults to 20 s; lower it (min 2 s) for signup forms, accepting more 'unknown' results.
filelist returns max 50 files per page.

4 moreShow fewer

No webhooks: bulk jobs must be polled.
Price drop is steep between 100K ($149) and 500K ($299): buying 500K costs only 2x the 100K pack.
Homepage says 'Risky Email Refund: full refund on any email we can't verify with certainty', but the terms give risky-result credits a cash refund value of zero (§5 and risky-results section).
Credits are consumed first-in, first-out across paid and promotional entries.

Who should use it

Use MillionVerifier for: Cheapest bulk cleaning of large lists (from $0.0039/credit at 10K down to $0.00016 at 50M)
Look elsewhere for: Needing documented rate limits or SLAs (none published)

If MillionVerifier is not the answer

Other Verification tools in this directory, each with its own review.

Bouncer

Verification

From $25/moOfficial MCP

Best for high-volume batch verification with clear published rate limits.

Best for bulk list cleaning through async jobs with callbacks.

NeverBounce API review

ZeroBounce

Verification

Free planOfficial MCP

Best for verifying every address before it enters a sequencer.

ZeroBounce API review

Before you build

Three things to settle first, each read off MillionVerifier's own pages.

Confirm the API is on your planAPI access starts on the 10,000 credits plan. Free tier: 100 free verification credits on signup, no card required (homepage, re-checked live 2026-10-25).
Keep the key out of your codeAPI key. It is sent as: query parameter: 'api' on the Single API, 'key' on the Bulk API.
Know the catch before you scaleThe 'we don't charge for catch-all or unknown' promise is, per the Terms of Service (published 19 Oct 2026), a discretionary goodwill promotion that can be changed or withdrawn without updating the terms. On bulk files the credit is deducted first and a Promotional Credit (zero cash value) is added back; on the API the credit may simply not be deducted.

Want us to build it for you?

Tell us what you want MillionVerifier to do in your stack. We will show you how we would wire it into your data, outbound or CRM, and what we would check first.

Book a call

See case studies

Read from millionverifier.com and developer.millionverifier.com. Verified 25 Oct 2026.

All 8 endpointsFor developers: method, path, what it does and what it costs.

Base URL: https://api.millionverifier.com (single) and https://bulkapi.millionverifier.com (bulk)

Bulk and async: Yes: Bulk API (upload CSV, poll fileinfo, download filtered report)

Filter endpoints

8 endpoints

Method	Path	What it does	Cost
GET	`/api/v3/`	Verify one email in real time	1 credit for good/bad results. For catch-all/unknown on the API, the terms say MillionVerifier 'may instead avoid deducting a Credit' under a discretionary goodwill programme that can be withdrawn at any time
GET	`/api/v3/credits`	Remaining credits	free
POSTasync	`/bulkapi/v2/upload`	Upload a file for bulk verification	1 credit per email is deducted on the file; where the goodwill programme is available, Promotional Credits (zero cash value) are then added back for eligible unknown and catch-all results
GETasync	`/bulkapi/v2/fileinfo`	Status of one file	free
GET	`/bulkapi/v2/filelist`	List files with filters	free
GETasync	`/bulkapi/v2/download`	Download a report	free
GET	`/bulkapi/stop`	Stop a file in progress	Not stated
GET	`/bulkapi/v2/delete`	Delete a file	free