How to Speed Up IntelliJ IDEA Startup by Modifying VM Options

When IntelliJ IDEA becomes sluggish after prolonged use, the primary remedy is to edit the idea64.exe.vmoptions file located in the IDE's bin directory and increase the JVM memory parameters.

The article shows the location of the file, displays a screenshot of the configuration file, and provides a sample configuration (Configuration 01) such as:

server
-Xms2048m
-Xmx2048m
-XX:ReservedCodeCacheSize=500m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-Djdk.http.auth.tunneling.disabledSchemes=""
-XX:+HeapDumpOnOutOfMemoryError
-XX:-OmitStackTraceInFastThrow

After saving the changes and restarting IDEA, the startup becomes noticeably faster.

If the above method does not take effect, the article suggests editing the VM options directly from the IDE via Help → Edit Custom VM Option... , and provides screenshots of the default settings and the edit dialog.

The guide then explains the meaning of key options:

-Xms : minimum heap size

-Xmx : maximum heap size

-XX:ReservedCodeCacheSize : size of the code cache

Because the default IDEA settings target low‑end machines (minimum 128 MB, maximum 512 MB), users with 8 GB or more RAM can benefit from larger values. The article provides two ready‑made configurations:

For 8 GB RAM:

-server
-Xms512m
-Xmx1024m
-XX:ReservedCodeCacheSize=300m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-Djdk.http.auth.tunneling.disabledSchemes=""
-XX:+HeapDumpOnOutOfMemoryError
-XX:-OmitStackTraceInFastThrow

For 16 GB RAM:

server
-Xms1024m
-Xmx2048m
-XX:ReservedCodeCacheSize=500m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50
-ea
-Dsun.io.useCanonCaches=false
-Djava.net.preferIPv4Stack=true
-Djdk.http.auth.tunneling.disabledSchemes=""
-XX:+HeapDumpOnOutOfMemoryError
-XX:-OmitStackTraceInFastThrow

The article concludes by encouraging readers to share any additional IDEA tips, plugins, or configuration tricks they discover.