How to Fix "IntelliJ IDEA Slow Performance on Large Projects"

If IntelliJ IDEA is running slowly on large projects, this could be due to the size of the project, insufficient memory allocation, or indexing issues.

To resolve this, follow these steps: First, ensure that IntelliJ is configured to use enough memory for large projects.

Open the idea.vmoptions file by going to Help > Edit Custom VM Options and increase the memory allocation by modifying the -Xmx and -Xms values.

For instance, change -Xmx1024m to -Xmx2048m to allocate more memory.

Increasing memory allocation can significantly improve IntelliJ’s performance when working with large projects.

Another common cause of slow performance is project indexing.

IntelliJ IDEA indexes project files in the background, which can slow down the IDE, especially for large projects.

To speed up indexing, exclude unnecessary directories such as build or log folders from being indexed.

Go to File > Settings > Directories, and mark these folders as Excluded.

IntelliJ IDEA will then skip indexing these files, which should improve performance.

If indexing is taking too long, you can also disable background processes.

Go to File > Settings > Appearance & Behavior > System Settings, and uncheck options like Synchronize files on frame or editor tab activation.

This will reduce the number of background processes and may help IntelliJ run faster.

Finally, consider using Power Save Mode to optimize IntelliJ’s performance when working with large projects.

Go to File > Power Save Mode, and IntelliJ will reduce its background tasks, allowing the IDE to run faster.

If performance is still an issue, try invalidating caches by going to File > Invalidate Caches / Restart, then selecting Invalidate and Restart.

This will clear the cache and restart IntelliJ IDEA, which can improve performance by removing any corrupted data.

By following these steps, IntelliJ IDEA should perform better on large projects.