Severe Lagging/Performance Issues in Latest IntelliJ IDEA Versions (2025.x+)

Ilnur Galimov I tried the suggested changes, but nothing has changed. Whit Dark Island theme there is still a fraction of a second lag on UX interactions (scrolling menus, clicking on any element of the IDE, etc.). Perfectly smooth with Dark theme.

Francesco Limberti, I'll inform the developers. Thank you for your cooperation! 

Hi Ilnur Galimov I'm chiming in this thread as I see it's about Performance Issues of latest IntelliJ IDEA version, and I'm facing a rather weird one, that I have already tried to describe in a Youtrack issue, but that issue was originally about Rider, and moreover I haven't got any reply yet.
So, since here you seem to be the right person to handle performance issues, maybe you can be interested to have a look at this one too.
You can find everything here: https://youtrack.jetbrains.com/issue/RIDER-127994/Excessive-CPU-usage-while-idle
 

For me IntelliJ 2025.2.6 (latest available update in 2025.2 line) was the version that made me switch to an alternate IDE (VSCode) as it made me unable to work.

 The previous version worked OK with the same projects. The 2025.2.6 version freezes after launching the UI, completely unresponsive UI. I insist that the big project I open is THE SAME that was working with previous versions. As you can see, two different workspaces open with different project types, both unresponsive. I need to do a kill -9. I repeat that with 2025.2 previous versions everything was fine. Even the window resizing does not work, as you can see in the attached screenshot.

WSL2

Distributor ID: Ubuntu
Description:    Ubuntu 24.04.3 LTS
Release:        24.04
Codename:       noble

6.6.87.2-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Thu Jun  5 18:30:46 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

 Idea process:

2307 pts/3    Sl   143:27 /snap/intellij-idea-community/693/bin/idea

It seems to be a incarnation of https://youtrack.jetbrains.com/issue/IDEA-383647/High-memory-usage-and-freezing-opening-large-Maven-projects-in-2025.2.6-at-MavenProjectsManagerinitProjectsTree

Tried to use dark theme but IDE is still terribly slow on Ubuntu. Mouse selection is slow, switching tab is slow, everything is slow…

Moved back to 2025.2.6 and everything is smooth again.

I think my problem is this one: IDEA-383647

Hello everyone! I'm an IntelliJ plugin developer and I have been struggling for days experiencing strange UI freezes when I execute my plugin with version 2025.3. The IDE completely freezes for about 90 seconds when I execute the plugin and after that time the plugin starts and works as expected. I accidentially stumbled upon this thread and switching back to dark theme solved my issue. No more freezes!

But starting the Gradle task “Run Plugin” inside the IDE still raises some exceptions I never saw before: IllegalStateException: No remote API found for com.intellij.kubernetes.splitApi.KubernetesApiProviderRpcRemoteApiDescriptorImpl. Thing is, I do not use Kubernetes module classes in my plugin… Maybe this helps analyzing the problem of the theme.

I have the same severe slowness issues. In my case, it (only) happens when having multiple projects open at the same time. None of the above solutions seem to have helped.

Hayo Baan , if you're opening big Maven projects, you might be affected by this one - https://youtrack.jetbrains.com/issue/IDEA-383438, please consult the workarounds inside the description.

It's silly, but in my case the latency with Islands theme gets significantly better when I set tool window bars visible (alt + quote). It's not quite as good as with the old themes, but much better than with Islands without bars. :)

Hello, same problems here with Webstorm 2025.3.1. 

I've disabled Dark Island, changed VM settings but the IDE is  still incredibly slow and unusable.

I use four instances of Webstorm: I noticed that also the terminal is very slow and if the debugger is active on some instances the IDE slows down even more

Even using the work-arounds described the performance of 2025.2 is better, than 2025.3. So I will have to stay on 2025.2 until the problems are fixed.

I'm facing this issue with Webstorm 2025.3 - but not with PyCharm 2025.3. 

macbook pro with M3 Max and MacOS 26.2.

Using Islands theme the stable workaround seem to be disabling the Metal render. It's not as smooth afterwards, but it avoids the complete freeze of the UI which otherwise happens every ~5 seconds.

I had the same issue described here - The UI was laggy - just opening a terminal tab or the project files window. Or moving a file selector in the Project Files Window.

I've applied the VM workaround “-Dsun.java2d.metal=false ” + Switched back to “Dark” theme.

That fixed the issue for me.

Let me know if you are interested in having the CPU usage profile from me.

Version: GoLand 2025.3 , 2025.3.1

Apple M3 Pro

MacOS version: 26.1 (Tahoe)

Project: Multiple Go micro services, Python code

Hi bruno, could you please share logs and CPU usage profiling during the time slowness is happening? As a workaround in the meantime, you can downgrade to the 2025.2.6 version of WebStorm and let us know if the issue persists.

I have the same problem

I confirm that Dark Islands theme causes lag in code editor in Intellij 2025.3.1.1

Switch theme to Dark (without Islands), and the lag is gone

This is unbearable. Even typing in a text file is so sluggish, I end up going to my browser to type things if i need to work on a prompt or something. I have no idea what its doing on each keystroke, but I have turned off basically everything. Even gave it 24GB of memory. On M3 MAX … no intellgence, no auto automcompletion … no grammar checks .. everything off … i have no idea. 

Can you imagine if typing in a text file is so sluggish how it is to consider doing serious coding? 

Hi, Opensource. Could you share if you tried the workaround mentioned above of switching to the Dark theme?
If yes and you still have the problem, please collect IDE logs via Help | Collect Logs and Diagnostic Data. You can upload logs securely at https://uploads.jetbrains.com/ and share the uploaded file ID in your reply.

RubyMine 2025.3.2 feels significantly faster than the previous version (I use Windows' WSL). I'm testing it today to verify whether the performance improvement is consistent.
 

Using the most recent version (idea-IU-253.30387.90) and the work-arounds described it seems like the lagging has been fixed. At least for me running IntelliJ in WSL Ubuntu.

 I'll will stay with this version for now and if I experience lagging again I will provide a full IDE log as requested.

2025.3.2 barely usable on Mac M2, even cursor movement without typing in 100 line long C# code is choppy. I've disabled all plugins I could and nothing helped. Interesting thing is that CPU runs at 30% or less and doesn't spike higher. GPU is also almost idle. Reverting to 2025.1 fixed it for me.

It doesn't look like typical performance issue, more like thread blocking or something like that. I've also noticed that icon on left gutter that represents context menu is slowly catching the cursor line by line when I moved quickly across multiple lines. That was not happening in older Riders. Old versions didn't update that while there was any user input.

Hi, Asmbot.

Could you share if you tried the workaround of switching from Islands Dark theme to Dark theme on 2025.3.2 and still had the problem after that?

Hello together, I also struggle with this problem. I uploaded the thread dump.

Upload id: 2026_02_05_zQuAmfiCPTTSYeE2UmUF1L (file: threadDump-20260205-203644-1770320204892.txt)

Downgrading to 2025.2 also didn't help.

Yes, I've tried that workaround and didn't help. From plugins I've disabled everything except: keymap plugins, Unity plugin and GitHub plugin. I have disabled also font smoothing, all inline hints and font is monospaced (looks old school but should run lightning fast).

Unfortunately even downgrade didn't help much, it was smooth for few hours and then it started with similar lags as the latest version. I've tried clearing caches and reloading project but it didn't work. Maybe there is a java cache that is not cleared with that procedure? Just guessing…

I've also tried opening and editing the same source code in totally different editor (vscode) and it was smooth as it should be, just to check if there is a system level problem.

For all of you still having problems: have you tried release 2025.3.2 already? For me this version fixed the issues and everything is running again, without the previous slowness. This Even with the Dark Island theme.

I've checked all system metrics and found something intriguing: when everything is loaded and I'm not making any input to Rider, my network traffic is under 50KB/s. But when I start just moving cursor in a single source file in Rider network traffic goes to 15MB/s and above and stays there while I'm scrolling.

While it is probably just a local traffic between Rider and Rider backend, isn't it a bit too much for just moving cursor around 100 lines of code?

Hi everyone!

I also started experiencing heavy lagging in IDEA 2025.3, sometimes it happens during typing, where I have to wait several seconds after a character I type appears on screen, or clicking at something produces a reaction after a second or two, this was not the case with 2025.2 and increasing the memory allocation did not help.

It is especially slow on viewing diff changes.

 MacOS 26.2, Apple M3 Pro 36GB RAM. I don't have any particular customizations, just the Darcula theme.

I have the exact same issue as Yurly Shatrov. My Mac is an M2, but otherwise experiencing the same. I have downgraded to 2025.2.5 which works much better.

I have tried 2025.3.2 which didn't help.

Alexander Pankow , does it help if you disable Symfony plugin?
 

Asmbot, can you upload a thread dump to our server and share the ID?