rust-lang/log

Health v2 · maintenance only

Adoption not part of the score

2544 stars · 287 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

The `log` crate is a lightweight logging facade for Rust that provides a single logging API abstracting over actual logging implementations. Libraries emit log messages via macros like `error!`, `warn!`, `info!`, `debug!`, and `trace!`, while executables choose a compatible logger implementation to produce output.

Use cases

• add logging to a Rust library without forcing a logger implementation
• emit structured log messages with levels and targets in Rust code
• swap logging backends like env_logger or log4rs without changing library code
• filter log output by level in Rust applications
• add key-value structured logging to Rust services

When to choose

• you are writing a Rust library that needs logging without a hard dependency on a specific logger
• you want the de facto standard logging API for the Rust ecosystem
• you need near-zero overhead when no logger is installed

When to avoid

• you need a ready-made logger with output formatting - pair this crate with an implementation like env_logger or log4rs
• you are not writing Rust code

Facets

library · maturity stable

logging developer-tools backend cross-platform rust logging-facade rust-crate structured-logging

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