created_at2016-06-12 23:00:53.182275
updated_at2024-01-05 09:14:23.10567
descriptionStructured, extensible, composable logging for Rust



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slog-rs - The Logging for Rust

You might consider using tracing instead

It's been a while since slog was created and it served Rust community well all this time. It remains a stable, featureful and battle-tested library, used in many important projects.

In last few years, another ecosystem for Rust was created with similar features and a very good support for debugging async code and already larger dev team and community.

Please check tracing and see if it is more suitable for your use-case. It seems that it is already a go-to logging/tracing solution for Rust.

Reasons you might want to stick with slog anyway:

  • async support doesn't benefit you
  • you consider mature, stable code & API a plus
  • it has some features that tracing is missing
  • great performance (I have NOT done any comparison, but slog's performance is very good).

Introduction (please read)

slog is an ecosystem of reusable components for structured, extensible, composable and contextual logging for Rust.

The ambition is to be The Logging Library for Rust. slog should accommodate a variety of logging features and requirements. If there is a feature that you need and standard log crate is missing, slog should have it.

This power comes with a little steeper learning curve, so if you experience any problems, please join slog-rs gitter channel to get up to speed. If you'd like to take a quick, convenient route, consider using sloggers wrapper library.

While the code is reliable, the documentation sometimes could use an improvement. Please report all issues and ideas.

Features & technical documentation

Most of the interesting documentation is auto-generated and hosted on

Go to to read about features and APIs (examples included).

Note: slog is just a core, and the actual functionality is inside many feature crates. To name a few:

There are many more slog feature crates. Search for more slog features on It is easy to write and publish new ones. Look through all the existing crates using slog for examples and ideas.

Terminal output example

slog-term is only one of many slog features - useful showcase, multi-platform, and featuring eg. automatic TTY detection and colors.

See following screenshot: same output in both compact and full output mode.

slog-rs terminal example output

Using & help

Please use slog-rs gitter channel to ask for help or discuss slog features.

See examples/ for full quick code example overview.

Read Documentation for details and features.

To report a bug or ask for features use github issues.

Slog community

Slog related crates are hosted under slog github organization.

Dawid Ciężarkiewicz is the original author and current maintainer of slog and therefore self-appointed benevolent dictator over the project. When working on slog Dawid follows and expects everyone to follow his Code of Conduct.

Any particular repositories under slog ecosystem might be created, controlled, maintained by other entities with various levels of autonomy. Lets work together toward a common goal in a respectful and welcoming atmosphere!

Verification Recommendation

To help with the maintained, the ownership of this crate is potentially shared between multiple developers. It is recommended to always use cargo-crev to verify the trustworthiness of each of your dependencies, including this one.

Commit count: 709

cargo fmt