MailHog vs MailCatcher
Two older Go and Ruby catchers, both trailing Mailpit on maintenance and HTML rendering.
What matters for early-stage startups
At an early stage the deciding factors are what the free tier actually covers, what the first paid invoice looks like, and how much of a founding engineer's week the setup costs. Feature depth that only matters at a million sends a month is noise until it is not.
| Priority | MailHog | MailCatcher |
|---|---|---|
| Free tier | Free, MIT-licensed | Free, MIT-licensed |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Starts at | Free | Free |
| DX score | 5/10 | 6/10 |
| Deliverability | Not applicable; capture-only. | Not applicable. |
| Operating since | Not published | Not published |
| Scheduling | No | No |
| SDKs | None | None |
| Webhooks | No | No |
For a pre-revenue or early-revenue team running a waitlist, a launch announcement, onboarding email, and the first transactional sends, 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 |
|---|---|---|
| Free tier | Free, MIT-licensed | Free, MIT-licensed |
| Starts at | Free | Free |
| DX score | 5/10 | 6/10 |
| Deliverability | Not applicable; capture-only. | Not applicable. |
| SDKs | None | None |
| Webhooks | No | No |
| Tagline | Classic local SMTP catcher (unmaintained since 2020). | Tiny Ruby-based local SMTP catcher. |
| 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