How to Set Log Level in Spring Boot: Simple Guide

In Spring Boot, you set the log level by adding logging.level.<logger-name>=<level> in your application.properties or application.yml file. For example, logging.level.org.springframework=DEBUG sets the Spring framework logs to debug level.

Syntax

Use the property logging.level.<logger-name>=<level> in your configuration file. Replace <logger-name> with the package or class name you want to control, and <level> with one of the log levels: TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF.

Example: logging.level.com.example=INFO sets the log level for the com.example package to INFO.

properties

logging.level.<logger-name>=<level>

Example

This example shows how to set the root log level to WARN and a specific package to DEBUG in application.properties. It controls the verbosity of logs for easier troubleshooting.

properties

logging.level.root=WARN
logging.level.org.springframework.web=DEBUG

Output

Logs from Spring Web package will show DEBUG and above, while other logs show WARN and above.

Common Pitfalls

• Forgetting to specify the correct logger name causes the setting to have no effect.
• Setting log level in the wrong configuration file or profile can lead to confusion.
• Using uppercase or lowercase inconsistently in log levels might cause issues; always use uppercase.
• Setting logging.level.root affects all logs globally, so use it carefully.

properties

Wrong:
logging.level.org.springframework=debug

Right:
logging.level.org.springframework=DEBUG

Quick Reference

Property	Description	Example
logging.level.root	Sets log level for all packages	logging.level.root=INFO
logging.level.	Sets log level for specific package	logging.level.com.example=DEBUG
logging.level.	Sets log level for specific class	logging.level.com.example.MyClass=TRACE
Log Levels	Available levels	TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF

Key Takeaways

Set log levels in Spring Boot using logging.level.= in application.properties or application.yml.

Use uppercase for log levels like DEBUG, INFO, WARN to avoid issues.

logging.level.root controls global log level; use it carefully.

Specify exact package or class names to control log verbosity precisely.

Check active profiles and configuration files to ensure log settings apply.