Quick verdict
Both tools solve the same core problem — catching test emails. Mailtrap is a mature, established player with a large team and broad feature set including email sending. MailHog.site is leaner, focused purely on SMTP testing with an editorial-quality dashboard, built-in spam scoring, and transparent per-client HTML compatibility checking.
Feature comparison
| Feature | MailHog.site | Mailtrap |
|---|---|---|
| SMTP email capture | ✅ | ✅ |
| Real-time inbox (SSE/WebSocket) | ✅ SSE | ✅ WebSocket |
| Spam scoring | ✅ Built-in rspamd | ✅ SpamAssassin |
| HTML compatibility checker | ✅ 12+ clients | ✅ Via Litmus |
| REST API for CI/CD | ✅ Hobby+ | ✅ All plans |
| Email sending (production) | ❌ Not in scope | ✅ Separate product |
| Team collaboration | ✅ Team+ | ✅ All plans |
| Header inspection | ✅ Full headers | ✅ Full headers |
| Attachment support | ✅ | ✅ |
| Free tier | ✅ 2 inboxes, 2,000/mo | ✅ 500 emails/mo |
| Self-hosted option | ❌ Hosted only | ❌ Hosted only |
When Mailtrap is the better choice
- You need email sending alongside testing (Mailtrap has a separate sending product)
- You want a more mature ecosystem with longer track record
- You need integrations with specific third-party tools
When MailHog.site is the better choice
- You want built-in spam scoring without third-party integrations
- You value a clean, editorial-quality dashboard UX
- You need per-client HTML compatibility checks built directly into the inbox
- You prefer a focused tool that does SMTP testing well rather than a platform that does everything
Pricing comparison
MailHog.site's free tier is 4x more generous (2,000 vs 500 emails/month). Our Hobby plan at $7/month includes API access and 15,000 emails — Mailtrap's comparable plan starts at $14.99/month. Team pricing starts at $19/month vs Mailtrap's $24.99/month.