PHP Logging Libraries
PHP logging libraries provide features specialized for web application development. Monolog complies with PSR-3 standard, easily integrates with major frameworks like Laravel and Symfony, and offers various handlers and formatters.
Key Features
- Multiple Output Levels
- Structured Logging
- High Performance
- Multiple Output Destinations
- Rich Ecosystem
Representative Libraries
- Pino: Ultra-fast JSON logging library
- Winston: Most versatile logging library
- Bunyan: Structured JSON-focused logging library
- Morgan: Express.js HTTP logging middleware
GitHub Star Comparison
| No | Name | GitHub Stars | Description | Trend | License | Type | Official Site |
|---|---|---|---|---|---|---|---|
| 1 | Monolog | - | De facto standard logging library for PHP. Default adoption in Laravel, Symfony, and Lumen. Implements PSR-3 interface, provides multiple handlers (file, database, email, Slack, etc.), processors, and formatters. | Absolute leader in PHP logging libraries for 2025. Monopolizes market share through default adoption in major frameworks. With increasing importance of structured logging, adoption continues expanding at enterprise level through JSON output functionality and cloud service integration. | MIT | Full-featured Framework | Official |
| 2 | PSR-3 Logger Interface | - | Common interface standard for logging libraries by PHP-FIG. Defines 8 log levels (emergency, alert, critical, error, warning, notice, info, debug). Abstraction layer promoting interoperability and code reusability between libraries. | Completely established as essential standard in PHP ecosystem for 2025. Functions as unified foundation for frameworks and libraries, guaranteeing compatibility when developers switch logging implementations. Increasing importance as foundation for unified log management in microservices era. | MIT | Interface Standard | Official |
| 3 | error_log() | - | PHP's built-in logging function. Immediately available without external dependencies, supports output to files, system logs, email, etc. Suitable for simple string-based log output, but limited in structured logging and advanced features. | Usage continues for small-scale scripts and quick debugging in 2025. Retains value as temporary log output means during learning stages and emergencies. However, migration to dedicated libraries like Monolog is strongly recommended for full-scale web applications due to feature limitations. | PHP License | Native Function | Official |
| 4 | file_put_contents() | - | Using PHP's standard file writing function for logging purposes. Enables simplest file log implementation, but features like log levels, rotation, formatting require manual implementation. Limited suitability for small-scale projects and learning purposes. | Limited to educational/learning purposes and proof of concept in 2025. Considered inappropriate for production-level applications, with dedicated libraries like Monolog being recommended. Risks of manual implementation recognized due to increasing complexity of log management. | PHP License | File Function | Official |
| 5 | Custom PSR-3 Logger | - | Custom logger implementing PSR-3 interface. Enables custom implementation tailored to specific requirements, handling special output destinations and processing logic not covered by existing libraries. Used in framework development and special applications. | Demand continues for framework developers and projects with special requirements in 2025. Flexibility to implement custom features while ensuring compatibility with other libraries through PSR-3 compliance is valued. However, trend prioritizes utilization of existing libraries considering maintenance burden. | Various | Custom Solution | Official |
| 6 | KLogger | - | Simple and lightweight PSR-3 compliant logging library. Lighter than Monolog, provides basic file logging functionality. Easy configuration, suitable for small-scale projects and lightweight logging requirements. Selected when minimizing dependencies is desired. | Adoption continues in projects prioritizing lightweight nature in 2025. Usage examples exist in small-scale applications wanting to avoid Monolog overhead and resource-constrained environments. However, adoption scope is limited due to inferior functionality richness compared to Monolog. | MIT | Minimal Framework | Official |