Open-source alternatives to Fmtlog

A lightweight C++ logging library

Zap is a high-performance structured logging library designed for production environments. It provides a framework for generating machine-readable logs that minimize memory overhead and CPU usage, allowing for efficient event analysis and system monitoring. The library distinguishes itself through a focus on zero-allocation logging, utilizing buffer pooling to reduce garbage collection pressure during high-frequency operations. It enforces strict data typing through compile-time checks and structured field encoding, which ensures consistent output without the performance cost of reflection-ba

Dear Log4j community,

Easyloggingpp is a C++ logging library and thread-safe logging framework used for recording diagnostic messages and application events. It functions as an asynchronous logger, processing messages on a background thread to reduce latency and prevent blocking the main execution path. The project includes a log rotation manager to automatically truncate or roll over files once they reach a specified disk size limit. It also serves as a performance tracking tool for measuring function execution timing and recording checkpoints to identify processing bottlenecks. The library covers a broad range

Simple Logger for Android

Tamper-evident audit log for Go: an append-only, hash-chained, optionally Ed25519-signed log/slog handler, with offline logx verify. Built on the standard library, zero third-party dependencies. Also a full slog toolkit (colored output, JSON, rotation, fan-out, CLI).

Rolling writer is an IO util for auto rolling write in go.

Minimalistic logging library for Go.

Boost Logging library

Example application using Bugfender SDK in Android

Colorful CLI logger

Logging, distilled

Seelog is a native Go logging library that provides flexible asynchronous dispatching, filtering, and formatting.

An golang log lib, supports tracking and level, wrap by standard log lib

Simple logger for Go programs. Allows custom formats for messages.

A tiny debug logging tool. Ideal for CLI tools and command applications. Inspired by https://github.com/visionmedia/debug

CocoaLumberjack is a logging framework designed for Apple platforms, providing a system for capturing, filtering, and managing diagnostic messages within mobile and desktop applications. It serves as a tool for monitoring software health and troubleshooting runtime issues by recording application events across various severity levels. The framework utilizes a modular architecture that allows developers to define custom log levels and route diagnostic output to multiple concurrent destinations, including the system console, local files, and remote servers. It incorporates an asynchronous pipel

go-spew is a deep inspection library and debugging utility for Go. It functions as a data structure pretty printer that renders complex, nested types into human-readable strings with indentation and type information. The library provides specialized capabilities for visualizing internal program states, including the ability to dump data structures with pointer addresses and map keys. It includes a configuration system to adjust printing behavior, such as limiting recursion depth and setting indentation. The tool uses reflection-based type inspection and recursive tree traversal to handle nes

Loguru is a Python logging library and thread-safe framework designed for recording system events and diagnostic messages. It functions as a structured logging tool that can serialize messages into JSON strings with metadata for automated parsing and analysis. The library includes a specialized exception tracker that captures unhandled crashes across main and background threads, rendering detailed stack traces that include local variable values. It further distinguishes itself through a unified routing pipeline that can intercept messages from the standard library logging module and dispatch

Timberjack is a Go log rolling library with support for size-based, time-based, and manual rotation.

This project is an application performance monitoring tool and JVM metrics library designed to measure workload behavior and export performance data to external monitoring databases. It serves as an instrumentation toolkit for tracking resource usage and internal runtime behavior within a Java execution environment. The system focuses on application performance measurement and JVM application monitoring, specifically tracking system health and runtime resource analysis to identify bottlenecks and stability issues. It provides a mechanism for external metrics export, sending captured data to t

Easyloggingpp is a header-only C++ logging framework and diagnostic tool designed for recording system events and diagnostic messages. It functions as a thread-safe logging library that synchronizes access across multiple concurrent execution threads to prevent data corruption during event recording. The framework features an asynchronous logger that processes messages on a background thread to minimize latency and prevent blocking the main application. It also acts as a log dispatcher, capable of routing data to local files, system syslog facilities, or remote network destinations for system

Simple Logging Facade for Golang

A powerful zero-dependency json logger.

CleanroomLogger provides an extensible Swift-based logging API that is simple, lightweight and performant

Very fast synchronous and asynchronous C++17 logging library