Real-Time Email Verification API - 340ms, 99.8% Accurate | BounceZero
Developer API

Email Verification API. 340ms Average.

Integrate real-time email verification into any workflow. BounceZero API returns a full verification result in under a second - valid, invalid, risky, catch-all, disposable, role-based - with a single REST call.

100 free verifications every month. No credit card required.

340ms
Average API response
99.8%
Verification accuracy
$3
Per 1,000 verifications
100
Free checks / month

Bad Emails Enter at the Point of Capture

Cleaning your list once a quarter treats the symptom. Typos, disposable addresses, and fake signups get in through your forms every single day - real-time API verification stops them at the door.

Typos Poison Your List Daily

Users mistype "gamil.com" and "hotmial.com" at signup constantly. Each one becomes a hard bounce that drags down your sender reputation. Email lists decay at roughly 22% per year - and every new day of unverified signups accelerates it.

Disposable Signups Skew Everything

Throwaway addresses from temporary inbox services inflate your user counts, burn free-trial abuse into your funnel metrics, and never convert. An API check at the form blocks them before they ever hit your database.

Batch Cleaning Is Always Behind

By the time a quarterly cleanup runs, invalid addresses have already received campaigns, triggered bounces, and hurt deliverability. Real-time verification means every address in your CRM was valid the moment it arrived.

Every API Call Runs 6 Verification Checks

One REST request, one JSON response - and behind it, a full verification pipeline completing in 340ms on average. Each response includes a status, a confidence score, and the individual check results.

Mailbox Existence

SMTP-level probe confirms the exact mailbox exists and accepts mail - not just that the domain resolves.

Catch-All Detection

A 3-probe test identifies domains that accept everything. Around 23% of B2B domains are catch-all - the API flags them as risky instead of falsely valid.

Role Account Detection

Flags info@, sales@, admin@ and other role-based addresses that engage poorly and trigger spam complaints.

Disposable Email Detection

Blocks temporary inbox services in real time using a continuously updated provider database.

MX Record Validation

Confirms the domain has live, correctly configured mail servers before deeper checks run.

Spam Trap Screening

Screens for known and suspected spam trap patterns so one bad signup never lands you on a blocklist.

From API Key to Production in Minutes

A single authenticated GET or POST request. No SDK lock-in, no webhooks required for single verifications, no complicated setup.

1

Create Your Free Account

Sign up at app.bouncezero.io - no credit card needed. Your account includes 100 free verifications every month.

2

Generate an API Key

Create a key from your dashboard in one click. Keys are scoped per project, so staging and production stay cleanly separated.

3

Send Your First Request

Call the verify endpoint with an email address and your key. Copy-paste examples for cURL, Python, PHP, Node.js, and Ruby are in the API docs.

4

Read the JSON Response

You receive a status (valid, invalid, risky, catch-all, disposable, role-based), a confidence score, and per-check details - in 340ms on average.

5

Act at the Point of Capture

Block invalid addresses at your signup form, suggest typo corrections, route risky addresses to double opt-in, and let clean signups straight through.

Simple Pricing. No API Surcharge.

API calls cost exactly the same as bulk verifications - $3 per 1,000. No monthly platform fee, no per-seat pricing, and your credits never expire.

Real-Time API

$3 / 1,000 verifications
  • 340ms average response time
  • All 6 verification checks on every call
  • 100 free verifications every month
View API docs

Need to Clean an Existing List?

Pair the API with bulk verification for your back catalog. Upload up to 500,000 emails per batch - a 10K list finishes in 5-10 minutes at the same $3 per 1,000 rate.

Not sure what cleaning is worth to you? Estimate your deliverability savings with our free calculator.

Real-Time Email Verification API - FAQ

Everything developers ask before integrating BounceZero.

How fast is the real-time email verification API?

The BounceZero API responds in 340ms on average, including SMTP-level mailbox checks. Some corporate mail servers respond slower, but the vast majority of verifications complete well under one second - fast enough to run inline on a signup form without hurting UX.

What does an API response look like?

Every call returns a JSON object with an overall status (valid, invalid, risky, catch-all, disposable, or role-based), a confidence score, and the result of each individual check: mailbox existence, catch-all detection, role account, disposable provider, MX records, and spam trap screening.

How accurate is the API compared to other providers?

BounceZero delivers 99.8% verification accuracy, versus an industry benchmark of roughly 95%. The biggest difference is catch-all handling: our 3-probe detection correctly flags catch-all domains - around 23% of all B2B domains - instead of marking them falsely valid.

How much does the email verification API cost?

API verifications cost $3 per 1,000 emails - the same rate as bulk verification, with no monthly platform fee and no API surcharge. Every account also includes 100 free verifications per month, no credit card required.

Can I verify a whole list through the API?

Yes. Alongside single real-time calls, the API supports bulk jobs of up to 500,000 emails per batch. A 10,000-email list typically completes in 5-10 minutes, and you can poll job status or download results programmatically.

Is there a free tier to test the API?

Yes - every account gets 100 free verifications per month with full API access and no credit card required. That is enough to integrate, test against real addresses, and validate the response format before you buy credits.

Ship Real-Time Verification Today

Get your API key, make your first call in minutes, and stop bad emails at the point of capture. 100 free verifications every month - no credit card required.

Get Your Free API Key

99.8% accuracy - $3 per 1,000 verifications - 340ms average response

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