head to head · open source
Plunk vs Hyvor Relay
Plunk has 5,474 GitHub stars, 401 forks, 61 open issues and last shipped 4 days ago. Hyvor Relay has 897 stars, 63 forks, 56 open issues and last shipped yesterday. Plunk leads on adoption by 510% (5,474 vs 897 stars). Plunk is written in TypeScript under AGPL-3.0; Hyvor Relay is written in PHP under AGPL-3.0. Plunk has attracted 7% as many forks as stars, Hyvor Relay 7%. Hyvor Relay was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Plunk | Hyvor Relay | |
|---|---|---|
| GitHub stars | ★ 5.5K | ★ 897 |
| License | AGPL-3.0 | AGPL-3.0 |
| Written in | TypeScript | PHP |
| Last push | 2026-09-14 | 2026-09-17 |
| Forks | ⑂ 401 | ⑂ 63 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Plunk if
- You weight community size — 5.5K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Hyvor Relay if
- You want the Hyvor Relay feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches PHP
- You evaluated both and Hyvor Relay fits your workflow better
About Plunk
Plunk is an open source email platform written in TypeScript and released under the AGPL 3.0 license. It combines transactional email, marketing campaigns, and workflow automation in a single system, and it is positioned as a self hosted alternative to SendGrid, Resend, and Mailgun. The project lives in the TypeScript and Node.js ecosystem, ships as a Docker image, and is documented at docs.useplunk.com with a community Discord for support.
read the full Plunk overview →
About Hyvor Relay
Hyvor Relay is an open source email API aimed at developers, written primarily in PHP with Symfony for the API backend and Go for the email workers, webhook handlers, DNS server, and incoming SMTP server. The frontend is built with SvelteKit and the Hyvor Design System, and PostgreSQL serves both as the database and as the queue. It lives in the PHP and Go ecosystems, is licensed under AGPL 3.0, and is positioned as a cloud and self hosted alternative to SES, Mailgun, and SendGrid.
read the full Hyvor Relay overview →
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Frequently asked questions
Is Plunk or Hyvor Relay more popular?
Plunk has 5,474 GitHub stars and Hyvor Relay has 897. Plunk has the larger community by that measure.
Are Plunk and Hyvor Relay free?
Both are open source. Plunk is licensed under AGPL-3.0 and Hyvor Relay under AGPL-3.0. Neither carries a licence fee.
What is the difference between Plunk and Hyvor Relay?
Plunk is written in TypeScript and Hyvor Relay in PHP. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Plunk or Hyvor Relay?
Choose Plunk if you want the larger community (5,474 stars) or its AGPL-3.0 licence terms. Choose Hyvor Relay if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.