head to head · open source
Grafana Loki vs semantic_logger
Grafana Loki has 29,124 GitHub stars, 4,174 forks, 1,620 open issues and last shipped yesterday. semantic_logger has 957 stars, 140 forks, 0 open issues and last shipped 2 days ago. Grafana Loki leads on adoption by 2,943% (29,124 vs 957 stars). Grafana Loki is written in Go under AGPL-3.0; semantic_logger is written in Ruby under Apache-2.0. Grafana Loki has attracted 14% as many forks as stars, semantic_logger 15%. Grafana Loki 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
| Grafana Loki | semantic_logger | |
|---|---|---|
| GitHub stars | ★ 29K | ★ 957 |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Go | Ruby |
| Last push | 2026-11-04 | 2026-11-03 |
| Forks | ⑂ 4.2K | ⑂ 140 |
| 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 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 Grafana Loki
Loki: like Prometheus, but for logs. Loki is a horizontally scalable, highly available, multi tenant log aggregation system inspired by Prometheus. It is designed to be very cost effective and easy to operate. It does not index the contents of the logs, but rather a set of labels for each log stream. Compared to other log aggregation systems, Loki: does not do full text indexing on logs. By storing compressed, unstructured logs and only indexing metadata, Loki is simpler to operate and cheaper to run. indexes and groups log streams using the same labels you’re already using with Prometheus, enabling you to…
read the full Grafana Loki 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 Grafana Loki or semantic_logger more popular?
Grafana Loki has 29,124 GitHub stars and semantic_logger has 957. Grafana Loki has the larger community by that measure.
Are Grafana Loki and semantic_logger free?
Both are open source. Grafana Loki is licensed under AGPL-3.0 and semantic_logger under Apache-2.0. Neither carries a licence fee.
What is the difference between Grafana Loki and semantic_logger?
Grafana Loki is written in Go 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, Grafana Loki or semantic_logger?
Choose Grafana Loki if you want the larger community (29,124 stars) or its AGPL-3.0 licence terms. Choose semantic_logger if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.