head to head · open source
Krayin vs Billion Mail
Krayin has 23,890 GitHub stars, 1,630 forks, 121 open issues and last shipped 4 days ago. Billion Mail has 15,611 stars, 1,702 forks, 236 open issues and last shipped 3 months ago. Krayin leads on adoption by 53% (23,890 vs 15,611 stars). Krayin is written in PHP under MIT; Billion Mail is written in Go under AGPL-3.0. Krayin has attracted 7% as many forks as stars, Billion Mail 11%. Krayin 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
| Krayin | Billion Mail | |
|---|---|---|
| GitHub stars | ★ 24K | ★ 16K |
| License | MIT | AGPL-3.0 |
| Written in | PHP | Go |
| Last push | 2026-09-14 | 2026-06-11 |
| Forks | ⑂ 1.6K | ⑂ 1.7K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Krayin if
- You weight community size — 24K stars and counting
- You want the MIT license terms
- Your stack matches PHP
- You value the larger contributor base for long-term maintenance
pick Billion Mail if
- You want the Billion Mail feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches Go
- You evaluated both and Billion Mail fits your workflow better
About Krayin
Krayin is a free, MIT licensed, self hosted customer relationship management framework built on Laravel and Vue.js, intended for small and medium businesses and enterprises that want to run customer, lead, and sales management on their own infrastructure.
read the full Krayin overview →
About Billion Mail
BillionMail is an open source mail server and email marketing platform written in Go and released under the AGPL 3.0 license. It lives in the self hosted email ecosystem and is described as a solution for newsletters, promotional emails, and transactional messages. The project combines mail server topics such as Postfix, Dovecot, Rspamd, and SMTP with campaign features such as customer management, analytics, templates, and sending control.
read the full Billion Mail overview →
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Frequently asked questions
Is Krayin or Billion Mail more popular?
Krayin has 23,890 GitHub stars and Billion Mail has 15,611. Krayin has the larger community by that measure.
Are Krayin and Billion Mail free?
Both are open source. Krayin is licensed under MIT and Billion Mail under AGPL-3.0. Neither carries a licence fee.
What is the difference between Krayin and Billion Mail?
Krayin is written in PHP and Billion Mail in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Krayin or Billion Mail?
Choose Krayin if you want the larger community (23,890 stars) or its MIT licence terms. Choose Billion Mail if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.