head to head · open source
monolog vs rsyslog
monolog has 21,405 GitHub stars, 1,910 forks, 3 open issues and last shipped yesterday. rsyslog has 2,336 stars, 736 forks, 207 open issues and last shipped 4 days ago. monolog leads on adoption by 816% (21,405 vs 2,336 stars). monolog is written in PHP under MIT; rsyslog is written in C under LGPL-3.0. monolog has attracted 9% as many forks as stars, rsyslog 32%. monolog was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (logging), so they are genuine substitutes rather than adjacent tools.
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
| monolog | rsyslog | |
|---|---|---|
| GitHub stars | ★ 21K | ★ 2.3K |
| License | MIT | LGPL-3.0 |
| Written in | PHP | C |
| Last push | 2026-09-19 | 2026-09-16 |
| Forks | ⑂ 1.9K | ⑂ 736 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick monolog if
- You weight community size — 21K stars and counting
- You want the MIT license terms
- Your stack matches PHP
- You value the larger contributor base for long-term maintenance
pick rsyslog if
- You want the rsyslog feature set and don't need the biggest community
- You prefer the LGPL-3.0 license terms
- Your stack matches C
- You evaluated both and rsyslog fits your workflow better
About monolog
Monolog is a logging library for PHP that sends log records to files, sockets, inboxes, databases, and various web services. It ships with the handlers, formatters, and processors needed to route records where they belong, and special handlers allow more advanced logging strategies than a single output stream. The library lives in the PHP ecosystem and is distributed through Packagist as monolog/monolog . It is released under the MIT license and has been developed for sixteen years, with more than twenty one thousand stars and roughly nineteen hundred forks on GitHub.
read the full monolog overview →
About rsyslog
Rsyslog is a high performance log ingestion and ETL engine written in C and released under the LGPL 3.0, built for operators and engineers who must take in, transform, and route very large volumes of log data from many sources to many destinations.
read the full rsyslog overview →
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Frequently asked questions
Is monolog or rsyslog more popular?
monolog has 21,405 GitHub stars and rsyslog has 2,336. monolog has the larger community by that measure.
Are monolog and rsyslog free?
Both are open source. monolog is licensed under MIT and rsyslog under LGPL-3.0. Neither carries a licence fee.
What is the difference between monolog and rsyslog?
monolog is written in PHP and rsyslog in C. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, monolog or rsyslog?
Choose monolog if you want the larger community (21,405 stars) or its MIT licence terms. Choose rsyslog if its feature set, stack or LGPL-3.0 licence fits better. Both are self-hostable.