head to head · open source
monolog vs viztracer
monolog has 21,402 GitHub stars, 1,920 forks, 3 open issues and last shipped 4 days ago. viztracer has 7,774 stars, 480 forks, 33 open issues and last shipped 1 months ago. monolog leads on adoption by 175% (21,402 vs 7,774 stars). monolog is written in PHP under MIT; viztracer is written in Python under Apache-2.0. monolog has attracted 9% as many forks as stars, viztracer 6%. 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 | viztracer | |
|---|---|---|
| GitHub stars | ★ 21K | ★ 7.8K |
| License | MIT | Apache-2.0 |
| Written in | PHP | Python |
| Last push | 2026-11-01 | 2026-09-26 |
| Forks | ⑂ 1.9K | ⑂ 480 |
| 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 viztracer if
- You want the viztracer feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Python
- You evaluated both and viztracer 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 viztracer
VizTracer VizTracer is a low overhead logging/debugging/profiling tool that can trace and visualize your python code execution. The front end UI is powered by Perfetto. Use "AWSD" to zoom/navigate . More help can be found in "Support Controls". Highlights Detailed function entry/exit information on timeline with source code Super easy to use, no source code change for most features, no package dependency Low overhead, probably the fastest tracer in the market Supports threading, multiprocessing, subprocess, async and PyTorch Powerful front end, able to render GB level trace smoothly Works on Linux/MacOS/Windows…
read the full viztracer overview →
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Frequently asked questions
Is monolog or viztracer more popular?
monolog has 21,402 GitHub stars and viztracer has 7,774. monolog has the larger community by that measure.
Are monolog and viztracer free?
Both are open source. monolog is licensed under MIT and viztracer under Apache-2.0. Neither carries a licence fee.
What is the difference between monolog and viztracer?
monolog is written in PHP and viztracer in Python. 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 viztracer?
Choose monolog if you want the larger community (21,402 stars) or its MIT licence terms. Choose viztracer if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.