head to head · open source
Grafana Loki vs viztracer
Grafana Loki has 29,120 GitHub stars, 4,173 forks, 1,620 open issues and last shipped yesterday. viztracer has 7,774 stars, 480 forks, 33 open issues and last shipped 1 months ago. Grafana Loki leads on adoption by 275% (29,120 vs 7,774 stars). Grafana Loki is written in Go under AGPL-3.0; viztracer is written in Python under Apache-2.0. Grafana Loki has attracted 14% as many forks as stars, viztracer 6%. 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 | viztracer | |
|---|---|---|
| GitHub stars | ★ 29K | ★ 7.8K |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Go | Python |
| Last push | 2026-11-04 | 2026-09-26 |
| Forks | ⑂ 4.2K | ⑂ 480 |
| 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 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 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 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 Grafana Loki or viztracer more popular?
Grafana Loki has 29,120 GitHub stars and viztracer has 7,774. Grafana Loki has the larger community by that measure.
Are Grafana Loki and viztracer free?
Both are open source. Grafana Loki is licensed under AGPL-3.0 and viztracer under Apache-2.0. Neither carries a licence fee.
What is the difference between Grafana Loki and viztracer?
Grafana Loki is written in Go 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, Grafana Loki or viztracer?
Choose Grafana Loki if you want the larger community (29,120 stars) or its AGPL-3.0 licence terms. Choose viztracer if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.