MailHog vs MailCatcher
Two older Go and Ruby catchers, both trailing Mailpit on maintenance and HTML rendering.
What matters for developers picking email infrastructure
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
| Priority | MailHog | MailCatcher |
|---|---|---|
| DX score | 5/10 | 6/10 |
| SDKs | None | None |
| Idempotency keys | No | No |
| Operating since | Not published | Not published |
| Event stream | No | No |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Webhooks | No | No |
| Deliverability | Not applicable; capture-only. | Not applicable. |
| Free tier | Free, MIT-licensed | Free, MIT-licensed |
For a developer-owned stack running password resets, receipts, and magic links shipped from application code, MailCatcher takes every priority that separates them here (developer experience), while MailHog matches it on the rest. On free tier, MailHog offers Free, MIT-licensed against Free, MIT-licensed from MailCatcher. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | MailHog | MailCatcher |
|---|---|---|
| DX score | 5/10 | 6/10 |
| SDKs | None | None |
| Webhooks | No | No |
| Deliverability | Not applicable; capture-only. | Not applicable. |
| Free tier | Free, MIT-licensed | Free, MIT-licensed |
| Tagline | Classic local SMTP catcher (unmaintained since 2020). | Tiny Ruby-based local SMTP catcher. |
| Starts at | Free | Free |
| Pricing model | self-hosted | self-hosted |
| API | Yes | Yes |
| SMTP | Yes | Yes |
| Templates | none | none |
| React Email | No | No |
| Inbound | No | No |
| Multi-tenant | No | No |
| Idempotency | No | No |
| Dedicated IP | No | No |
| Best for | Legacy projects already wired to it. | Rails teams already running it in development. |
MailHog
- ›Familiar from years of tutorials and boilerplates
- ›Single Go binary with a Docker image and a chaos-testing mode
- ›No meaningful releases since 2020
- ›HTML and modern CSS rendering trails current email clients
- ›Open issues and pull requests are effectively unattended
MailCatcher
- ›Installs as a Ruby gem, familiar in Rails stacks
- ›SMTP on 1025 with a web UI and JSON API on 1080
- ›Shows HTML, plain text, and raw source per message
- ›Release cadence is slow with little active feature work
- ›Needs a Ruby runtime where Mailpit ships a static binary
- ›HTML rendering trails newer catchers