head to head · open source
Grafana Loki vs monolog
Grafana Loki has 28,909 GitHub stars, 4,112 forks, 1,620 open issues and last shipped yesterday. monolog has 21,406 stars, 1,910 forks, 3 open issues and last shipped 9 days ago. Grafana Loki leads on adoption by 35% (28,909 vs 21,406 stars). Grafana Loki is written in Go under AGPL-3.0; monolog is written in PHP under MIT. Grafana Loki has attracted 14% as many forks as stars, monolog 9%. Grafana Loki was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (hacktoberfest, 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
| Grafana Loki | monolog | |
|---|---|---|
| GitHub stars | ★ 29K | ★ 21K |
| License | AGPL-3.0 | MIT |
| Written in | Go | PHP |
| Last push | 2026-09-17 | 2026-09-09 |
| Forks | ⑂ 4.1K | ⑂ 1.9K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Grafana Loki if
- You weight community size — 29K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick monolog if
- You want the monolog feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches PHP
- You evaluated both and monolog fits your workflow better
About Grafana Loki
Grafana Loki is a log aggregation system designed as the log oriented counterpart to Prometheus. It operates within the cloud native observability ecosystem, specifically targeting Kubernetes and containerized environments. Loki avoids expensive full text indexing by indexing only metadata labels attached to log streams, storing the raw log content in compressed form. This design choice makes Loki significantly simpler to operate and more cost effective than traditional log systems that index every word.
read the full Grafana Loki overview →
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 →
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Frequently asked questions
Is Grafana Loki or monolog more popular?
Grafana Loki has 28,909 GitHub stars and monolog has 21,406. Grafana Loki has the larger community by that measure.
Are Grafana Loki and monolog free?
Both are open source. Grafana Loki is licensed under AGPL-3.0 and monolog under MIT. Neither carries a licence fee.
What is the difference between Grafana Loki and monolog?
Grafana Loki is written in Go and monolog 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, Grafana Loki or monolog?
Choose Grafana Loki if you want the larger community (28,909 stars) or its AGPL-3.0 licence terms. Choose monolog if its feature set, stack or MIT licence fits better. Both are self-hostable.