Debugging large Spring Boot JDK 8 projects is very slow under IDEA 2025.1 or higher version

Problem

1. Open a large Spring Boot project in IntelliJ IDEA
2. Set up a debug configuration for the project
3. Start the application in debug mode using:
   • IntelliJ IDEA 2024.2 (baseline)
   • IntelliJ IDEA 2025.1.3 (2024.3 is also very slow)
4. Measure the time until the application fully starts

Cause

A known debugger bug causes this: the "Recording time with run to cursor" feature slows down debug mode for large Spring Boot projects. In one measurement, startup took 2004 s in 2025.1.3 against 460 s in 2024.2.

Similar: idea启动项目极慢

Resolution

Workaround

1. Start the application in debug mode.

2. Set your cursor over the gutter on any line(set at the left of the editor):

   

3. Right-click on it and select the option Disable Recording Time with Run to Cursor in the context menu:

   

or

1. Open the IDE
2. In the main menu, go to Navigate | Search Everywhere or press ⇧Shift twice to open the search window
3. Type Disable Recording Time with Run to Cursor and select this option:
4. 

Check with an updated JDK

If debug startup is still slow, check whether the slowdown also happens with an updated JDK:

1. In the main menu, go to File | Project Structure | Project Settings | Project.
2. In the SDK list, select the latest update release of the JDK version the project uses, for example the latest JDK 8 update. If it is not on your computer, select Download JDK.
3. Apply the changes, start the application in debug mode again, and compare the startup time.

Additional information

When Recording Time with Run to Cursor is enabled, the sticky balloon notification appears in the bottom-right corner: