What is debug logging?

Debug logging is a special, more detailed logging mode that records internal IDE activity to help investigate and reproduce problems that are not visible from regular logs. By default, the IDE writes only messages with the info level and higher to idea.log, which is usually enough for normal work and basic troubleshooting.

When you enable debug logging for specific categories (Java packages), the IDE starts writing additional messages with more fine‑grained levels such as debug, trace, or all, which provide much more context about what is happening inside the IDE (HTTP requests, indexing details, VFS events, UI behavior, etc.). This extra information is what JetBrains Support typically needs when diagnosing complex or rare issues.

Because debug logs may contain internal paths, configuration details, request data, and other sensitive information, they should normally be enabled only when requested by Support (or when you are actively troubleshooting) and turned off again afterwards.

If you don't know what package to use as a category, contact JetBrains Support for assistance via Help | Contact Support.

Question

How to enable debug logging in IntelliJ IDEA?

Answer

In the IDE, go to Help | Diagnostic Tools | Debug Log Settings...
In the textbox that opens, add required debug instructions (Java package name followed by log level), one per line, and click OK:

Note: no IDE restart is required.
Reproduce the issue and collect IDE logs using Help | Show Log in... (idea.log) or Help | Collect Logs and Diagnostic Data (all IDE logs and thread dumps).

Logging levels

INFO - normal logging level, records high‑level, important events (e.g., "project opened", "indexing finished", major warnings)
DEBUG (correlates to FINE) - detailed diagnostic messages about what the IDE is doing (more than INFO logs)
TRACE (correlates to FINER) - extremely fine‑grained, step‑by‑step messages (even more verbose than DEBUG)
ALL - logs every message for that category, regardless of level (maximal verbosity)

⚠️ Notes

Messages with INFO level and higher are written to idea.log by default (so you get them even without enabling debug logging)
If you add only the package name (e.g., com.intellij.diagnostic) without a log level, the level defaults to DEBUG
Logging levels need to be specified after the Java package name: com.intellij.execution:debug
Logging levels are case-insensitive, so both :trace and :TRACE are OK
Categories (packages) are case-sensitive
Categories (packages) use Java package naming convention with dots (.)
In newer IDE versions, # in front of the package name is optional (example: #com.intellij.util.io.HttpRequests:all)

More details about IntelliJ Platform logging capabilities can be found in this documentation article.

Examples

Common categories for which to enable logging when troubleshooting specific subsystems / scenarios:

HTTP requests and Proxy

com.intellij.util.io.HttpRequests:trace
com.intellij.util.proxy.CommonProxy:trace
com.intellij.util.net:trace

Task server connection

Everything related to Task Management functionality:

com.intellij.tasks:all
httpclient.wire.header:all

SSH

com.intellij.ssh

IJent (IntelliJ Remote Agent)

What is IJent: IJPL-A-166

⚠️ Note: With this option enabled, IDE logs can contain a lot of sensitive information.

com.intellij.platform.ijent

Editor Scrolling

com.intellij.openapi.editor.impl.ScrollingModelImpl:all

Indexing

com.intellij.util.indexing.FileBasedIndexImpl:trace

Git, GitHub, GitHub Copilot

output.git4idea.commands.GitHandler
org.jetbrains.plugins.github
com.github.copilot

File system input/output (I/O)

com.intellij.openapi.util.io.FileSystemUtil:trace

File system watch roots

Details in IJPL-A-1528.

com.intellij.openapi.vfs.WatchRoots:trace

File system refresh

Details in IJPL-A-1528.

com.intellij.openapi.vfs.newvfs.RefreshSession:trace
com.intellij.openapi.vfs.newvfs.RefreshWorker:trace

Terminal (external changes)

Troubleshooting flags when external changes aren't detected until focus moved out of Terminal (IJPL-A-1684):

2026.1:

com.intellij.terminal.frontend.view.impl.TerminalVfsSynchronizer:trace
com.intellij.terminal.frontend.view.impl.TerminalHeuristicsBasedCommandFinishTracker:trace

2026.2 and later versions:

com.intellij.terminal.TerminalVfsSynchronizerKt
com.intellij.terminal.frontend.view.impl.TerminalVfsSynchronizerKt
com.intellij.terminal.frontend.view.impl.TerminalHeuristicsBasedCommandFinishTracker

Keyboard and mouse input events

java.awt.event.InputEvent:all
java.awt.event.EventQueue:all
java.awt.event.EventDispatchThread:all
java.awt.event.Component:all
java.awt.event.Container:all
java.awt.event.LightweightDispatcher:all
java.awt.event.WaitDispatchSupport:all

Size and position of monitors and related events (JBR)

Go to Help | Edit Custom VM Options, add the following as a new line there, then restart the IDE:

-Dsun.java2d.logDisplays=true

Scale and font initialization on IDE startup

com.intellij.ide.ui.laf.LafManagerImpl

Implementation details: IJPL-159968

Size and position of tool windows and detached Editor tabs

Note: for detached Editor tabs, use the last two options.

com.intellij.openapi.wm.impl.ToolWindowManagerImpl
com.intellij.toolWindow.ToolWindowPane
com.intellij.openapi.wm.impl.FloatingDecorator
com.intellij.openapi.ui.FrameWrapper

Size and position of the main IDE window

ide.frame.events

Implementation details: Log IDE frame events related to saving size, location and screen

Size and position of popups

com.intellij.ui.popup.AbstractPopup
com.intellij.codeInsight.hint.HintManager
com.intellij.codeInsight.lookup.impl.LookupUi

Implementation details: IJPL-124033

Position of context menus

com.intellij.openapi.ui.JBPopupMenu

Implementation details: Add logging for context menu positioning

Auto-selection of item in the Project tree

com.intellij.ide.projectView.impl.SelectInProjectViewImpl
com.intellij.ide.impl.SelectInTargetPsiWrapper
com.intellij.ide.projectView.impl.AsyncProjectViewSupport
com.intellij.ui.tree.BgtTreeWalker
com.intellij.ui.tree.AsyncTreeModel:trace

Switcher and Recent Files

Use case example: unexpected files are shown or certain files are missing

com.intellij.platform.recentFiles:all

AI Assistant (LLM)

com.intellij.ml.llm
com.intellij.util.io.HttpRequests:trace
com.intellij.util.proxy.CommonProxy:trace
com.intellij.util.net:trace

Action System

Use case example: some menu does not show up at all, or certain menu items are missing:

com.intellij.openapi.actionSystem.impl.Utils

Undo / Redo actions work incorrectly / greyed out in the menu

com.intellij.openapi.command.impl.StacksHolderBase:all
com.intellij.openapi.command.impl:all

Actions in Remote Development / Code With Me:

com.jetbrains.rdclient.actions.base.FrontendActionUpdateInterceptor

Terminal subsystem / process execution

org.jetbrains.plugins.terminal:trace
com.jediterm.terminal:trace
com.intellij.execution:trace

Plugins download from the marketplace

com.intellij.ide.plugins.marketplace

JCEF

Go to Help | Edit Custom VM Options, add the following as a new line there, then restart the IDE:

-Dide.browser.jcef.log.level=verbose

Java Debugger

See article: Collecting Java debugger logs

IDE scripting console + Groovy console

com.intellij.ide.script
com.intellij.ide.script.RunIdeConsoleAction
com.intellij.ide.script.IdeScriptEngineManagerImpl
org.jetbrains.plugins.groovy