head to head · open source
monolog vs semantic_logger
monolog has 21,401 GitHub stars, 1,920 forks, 3 open issues and last shipped 4 days ago. semantic_logger has 957 stars, 140 forks, 0 open issues and last shipped 2 days ago. monolog leads on adoption by 2,136% (21,401 vs 957 stars). monolog is written in PHP under MIT; semantic_logger is written in Ruby under Apache-2.0. monolog has attracted 9% as many forks as stars, semantic_logger 15%. semantic_logger 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 | semantic_logger | |
|---|---|---|
| GitHub stars | ★ 21K | ★ 957 |
| License | MIT | Apache-2.0 |
| Written in | PHP | Ruby |
| Last push | 2026-11-01 | 2026-11-03 |
| Forks | ⑂ 1.9K | ⑂ 140 |
| 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 semantic_logger if
- You want the semantic_logger feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Ruby
- You evaluated both and semantic_logger fits your workflow better
About monolog
Monolog Logging for PHP Note This is the documentation for Monolog 3.x , if you are using older releases see the documentation for Monolog 2.x or Monolog 1.x Monolog sends your logs to files, sockets, inboxes, databases and various web services. See the complete list of handlers below. Special handlers allow you to build advanced logging strategies. This library implements the PSR 3 interface that you can type hint against in your own libraries to keep a maximum of interoperability. You can also use it in your applications to make sure you can always use another compatible logger at a later time. As of 1.11.0…
read the full monolog overview →
About semantic_logger
Semantic Logger Semantic Logger is a high performance, asynchronous structured logging framework for Ruby and Rails. It differs from ordinary loggers in two important ways: 1. It logs structured data, not just strings. Along with the text message, each log entry can carry a payload (any Hash), an exception, a duration, metrics, and tags. That data is preserved all the way to the destination, so it stays searchable instead of being flattened into text. 2. It logs asynchronously. Log events are pushed onto an in memory queue and written to their destinations by a separate background thread, so your application is…
read the full semantic_logger overview →
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Frequently asked questions
Is monolog or semantic_logger more popular?
monolog has 21,401 GitHub stars and semantic_logger has 957. monolog has the larger community by that measure.
Are monolog and semantic_logger free?
Both are open source. monolog is licensed under MIT and semantic_logger under Apache-2.0. Neither carries a licence fee.
What is the difference between monolog and semantic_logger?
monolog is written in PHP and semantic_logger in Ruby. 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 semantic_logger?
Choose monolog if you want the larger community (21,401 stars) or its MIT licence terms. Choose semantic_logger if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.