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NoBounch
Developer API

Email verification API for your app and signup forms

Verify emails in real time with one REST call, or send a whole CSV or Excel (.xlsx) file and download the results when it is done. Same credits as the dashboard, no separate plan.

Start free with 20 credits See pricing

Real-time checks

Verify an address while a user fills in your signup or checkout form and stop fake or mistyped emails.

Bulk endpoint

Upload a CSV or Excel (.xlsx) file over the API, poll its progress, and download full, valid, invalid, catch-all, disposable or unknown results.

Clear JSON results

Each check returns valid, invalid, catch_all, disposable or unknown, plus a reason, typo suggestion, role and free provider flags.

Secure API keys

Create and revoke keys in your dashboard. Keys are stored hashed and only shown once.

Fair rate limits

Built-in rate limits protect your credits from runaway scripts and keep the service fast for everyone.

Pay as you go

API checks use the same credits as the dashboard. Unknown results are refunded.

Verify one email

Send a POST request with the address. Use the key from your dashboard as a Bearer token.

curl -X POST https://nobounch.com/api/v1/verify \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Accept: application/json" \
  -d "email=jane@company.com"

Example response:

{
  "email": "jane@company.com",
  "result": "valid",
  "reason": null,
  "free_provider": false,
  "role_address": false,
  "did_you_mean": null,
  "credits_remaining": 4999
}

Verify a CSV or Excel list

# 1. Upload the file
curl -X POST https://nobounch.com/api/v1/bulk \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Accept: application/json" \
  -F "file=@leads.csv"

# 2. Check progress with the id from step 1
curl https://nobounch.com/api/v1/bulk/LIST_ID \
  -H "Authorization: Bearer YOUR_API_KEY" -H "Accept: application/json"

# 3. Download the valid emails (or full, invalid, catch_all, disposable, unknown)
curl -o valid.csv https://nobounch.com/api/v1/bulk/LIST_ID/download/valid \
  -H "Authorization: Bearer YOUR_API_KEY"

Endpoints

  • POST /api/v1/verify verifies one email address.
  • POST /api/v1/bulk uploads a CSV or Excel (.xlsx) list.
  • GET /api/v1/bulk/{id} shows the list's status and result counts.
  • GET /api/v1/bulk/{id}/download/{type} downloads results: full, valid, invalid, catch_all, disposable or unknown.
  • GET /api/v1/account shows your credit balance.

Errors use normal HTTP codes: 401 for a missing or wrong key, 402 when you are out of credits, 422 for invalid input, 429 when you hit the rate limit, and 503 if verification is briefly unavailable.

Prefer a dashboard? Use the online email verifier or bulk upload instead.

Questions people ask

How do I get an API key?

Create a free account, open API keys in the dashboard and create a key. Send it as a Bearer token in the Authorization header.

What does the API return?

JSON with the email, the result (valid, invalid, catch_all, disposable or unknown), a reason, a did_you_mean typo suggestion, role and free provider flags, and your remaining credits.

Is there a sandbox or free tier?

New accounts get free credits after confirming their email, which you can use with the API.

Can I verify a list over the API?

Yes. POST a CSV or Excel (.xlsx) file to the bulk endpoint, check its status, and download the results by type when it is completed.

Send to real inboxes only

Create a free account, verify your first emails and only pay for what you check. Credits never expire.

Create free account