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⚡ RESTful Email Verification API

Block Toxic Emails at the Point of Sign-Up.

Verify email deliverability in real time with a lightweight, synchronous HTTP request. Protect registration forms, checkouts, and backend pipelines.

Instant provisioning • No credit card required • HTTP POST JSON API
Developer REST API

Simple REST API for Real-Time Verification

Protect your registration forms, SaaS checkouts, and backend pipelines from disposable emails, typos, and toxic leads with a single lightweight HTTP request.

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    Real-Time Synchronous Validation: Designed for live sign-up forms, user onboarding, and webhook listeners.
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    Rich Diagnostic Attributes: Returns deliverability status, disposable domain flags, role-based accounts (info@), and free webmail detection.
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    Instant API Key & Free Credits: Start testing in seconds with 100 free credits upon sign-up — no credit card required.
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    Copy-Paste Snippets for 9+ Languages:Full documentation with implementation examples for Python, PHP, Node.js, Ruby, Go, Java, and more.
Explore Full API Documentation →
// Request:
curl --request POST \
--url https://app.nullbounce.com/api/v1/validate/ \
--header 'accept: application/json' \
--header 'authorization: Token YOUR_API_KEY' \
--header 'content-type: application/json' \
--data '{"email": "alex@company.com"}'
// Response (JSON):
{
  "email": "alex@company.com",
  "result": "Safe",
  "status_text": "Valid",
  "substatus_text": null,
  "is_disposable": false,
  "is_role": false,
  "is_free": false
}

Built for High-Volume Production Workloads

Engineered for developers who demand clean JSON payloads, transparent rate limits, and zero fluff.

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Disposable Email Detection

Instantly identify burner domains from services like Mailinator, 10MinuteMail, and GuerrillaMail. Block fake trial abuse and bot registrations before they pollute your database.

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Role & Free-Mail Flags

Every JSON response flags generic role addresses (info@, support@) and free consumer providers (Gmail, Yahoo) to easily enforce B2B corporate domain rules.

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Generous Rate Limits (600/min)

Enjoy high-throughput concurrency out of the box. Send up to 10 requests per second (600 requests/minute) on standard tiers without artificial throttling or latency penalties.

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Standard Token Authentication

Authenticate via a standard HTTP header (Authorization: Token YOUR_API_KEY). Integrates with any language or backend framework in under 5 minutes.

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Multiple API Keys & Teams

Generate independent API tokens for production, staging, and development environments. Share a centralized balance across your engineering team with free Team Accounts.

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Credits Never Expire

Credits purchased for API calls never expire. Fund your account once and make live queries over weeks, months, or years without monthly recurring subscription fees.

Comprehensive JSON Response Schema

Every verification returns structured diagnostic attributes for automated logic handling.

ParameterTypeDescription
resultStringPrimary verdict: Safe, Invalid, Risky, or Unknown.
status_textStringDetailed deliverability state: Valid, Invalid, Catch_all, or Unknown.
substatus_textString | nullSpecific error reason if rejected: e.g. Mailbox Not Found, Failed Syntax Check, or No Smtp.
is_disposableBooleantrue if domain belongs to a temporary or burner email provider (e.g. Mailinator).
is_roleBooleantrue for role-based accounts (info@, support@, sales@).
is_freeBooleantrue for public consumer webmail providers like Gmail, Yahoo, or Outlook.com.

Your Contact Lists Are Safe With Us

Enterprise-grade privacy standards applied to every verification job.

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256-Bit SSL Encryption

All file uploads, API requests, and downloads are protected by modern end-to-end TLS encryption.

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Auto-Wiped in 30 Days

Uploaded lists and validation results are permanently purged from our servers after 30 days. You can also delete them manually at any time.

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Zero Data Sharing

We never sell, rent, or share your proprietary lead lists with third parties. Your data is strictly yours.

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No Real Emails Sent

Our engine performs technical DNS and SMTP handshakes, terminating before delivery. Your contacts will never receive test messages.

Start Verifying in Under 60 Seconds

Create a free account, grab your API key, and make your first live validation call right now.