If you do B2B outreach, you’ve almost certainly used Hunter.io (or considered it). It’s been the go-to tool for finding professional email addresses since 2015. Seek API offers some of the same capabilities as part of a broader worker ecosystem. This comparison explains where each excels.
What Hunter.io does
Hunter.io is a domain-based email finding tool. Its primary features:
- Domain Search: Enter a domain, get a list of email addresses Hunter has found for people at that company
- Email Finder: Enter a person’s name and company domain, get their best-guess email address
- Email Verifier: Validate whether an email address is deliverable (MX check, SMTP ping)
- Bulk operations: CSV upload for batch domain search, email finding, and verification
- CRM integrations: HubSpot, Salesforce, Pipedrive native integrations
- Chrome extension: Find emails from LinkedIn profiles and company sites directly in browser
Hunter’s data comes from a mix of crawled public pages, user submissions, and enrichment databases. Match rates are solid for established companies; coverage drops for startups, SMBs, and non-English markets.
Hunter.io pricing
| Plan | Price | Requests/month |
|---|---|---|
| Free | $0 | 25 searches, 50 verifications |
| Starter | $34/month | 500 searches |
| Growth | $104/month | 5,000 searches |
| Business | $349/month | 50,000 searches |
Each “search” is either a domain search or an email finder lookup. Verification is separate. At the Business tier, Hunter charges $349/month for 50,000 searches — $0.007 per search.
Email capabilities on Seek API
Seek API offers workers for:
Email verification: Full SMTP-level validation including MX record check, SMTP handshake, catch-all detection, role-address detection.
POST /v1/workers/email-verifier/jobs
{ "email": "[email protected]" }
Returns:
{
"email": "[email protected]",
"status": "valid",
"deliverable": true,
"mxRecords": ["microsoft-com.mail.protection.outlook.com"],
"catchAll": false,
"disposable": false,
"roleAddress": false,
"confidence": 0.94
}
LinkedIn-to-email enrichment: Given a LinkedIn profile URL, find the associated professional email.
Domain email pattern detection: Given a domain, identify the email pattern used (firstname.lastname@, flastname@, etc.).
Cost comparison
| Task | Hunter.io | Seek API |
|---|---|---|
| 500 email finds | $34/month (Starter) | ~$5 |
| 5,000 email finds | $104/month | ~$50 |
| 50,000 email finds | $349/month | ~$500 |
| 50,000 email verifications | Additional credits | ~$250 |
At moderate volumes, Seek API’s per-result pricing is substantially cheaper. At high volumes, Hunter’s subscription starts to become more competitive because you’re paying a flat rate regardless of usage.
Match rate and data quality
Hunter.io’s decades of data collection means strong match rates for established companies. It has indexed email addresses from public sources extensively.
Seek API workers find emails through:
- LinkedIn profile enrichment
- Company website extraction
- Pattern-based inference
Match rates are comparable for mid-market companies; Hunter tends to have better raw coverage for very large enterprises and academic institutions where email addresses are indexed across many public documents.
When Hunter.io has a clear advantage
- Browser extension: Hunter’s Chrome extension finds emails as you browse LinkedIn. There’s no equivalent in a pure API workflow.
- Domain search breadth: Hunter’s indexed database provides instant results for common domains without job submission delay.
- CRM native integrations: If your team uses HubSpot or Salesforce, Hunter’s native one-click CRM push is faster to configure than a coded integration.
- Team collaboration features: Shared lists, team limits, and usage dashboards for coordinated outreach teams.
When Seek API is the better choice
- Programmatic workflows: If enrichment is triggered from code (new signups, pipeline automation), API-first architecture is cleaner.
- High-volume batch enrichment: At 50,000+ records, pay-per-result is cheaper than Hunter’s top subscription tier.
- Combined enrichment pipeline: Seek API lets you chain email finding with LinkedIn profile enrichment, company data, and tech stack detection in one pipeline — not just email finding.
- No monthly commitment: For irregular use (a one-off prospecting campaign), pay-as-you-go is more efficient than a monthly seat.
The practical answer
Hunter.io is the right choice for outreach-focused teams that want a polished UI, browser extension, and CRM integration out of the box — with email finding as the primary use case.
Seek API is the right choice for developers building enrichment into products, running batch pipelines, or needing email verification as one of several data worker capabilities in a broader automation stack.
Many growth teams use Hunter for individual prospecting through the UI, and Seek API’s email verifier for programmatic bulk verification of larger lists before sending campaigns. The combination covers both use modes.