GitHub Copilot for Xcode 0.43.0 Update Causing Extreme CPU Usage and System Lag

[mfcguin]

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After updating GitHub Copilot for Xcode to version 0.43.0, my MacBook has become extremely sluggish with high CPU usage and constant fan noise. The entire system is barely usable when the extension is active.

System Specs

Device: MacBook Pro M1 Pro
RAM: 32GB
macOS Version: [15.6]
Xcode Version: [16.4]
Copilot Version: 0.43.0

[phuanggh]

Same here.
After upgrading Copilot for Xcode to version 0.43.0, I started encountering the following issues in Xcode:

• Severe typing lag.
• Sometimes when typing a whole word, only the first character is registered.
• Pressing Tab often does not respond, and when AI suggestions (greyed text) appear, both the typing lag and the missed input become worse.
• The error icon overlaps with the AI suggestion (greyed text).
• After inserting AI suggestions with Tab, the editor occasionally scrolls to an incorrect position.

These issues significantly affect my development workflow and force me to disable Copilot for Xcode.

System Specs

Device: Mac mini M1
RAM: 16 GB
macOS Version: 15.2
Xcode Version: 16.2
Copilot Version: 0.43.0

[KaloudasDev]

Hey @mfcguin and @phuanggh,

Thanks for reporting this, definitely sounds like something’s gone wrong with the latest Copilot for Xcode update.

You're both seeing symptoms that suggest the Copilot extension is introducing serious performance regressions in version 0.43.0, particularly on Apple Silicon devices running macOS 15+ and Xcode 16.x.

What Might Be Happening

Several possible culprits based on your reports:

• Inefficient token scanning/parsing: Copilot might be aggressively scanning the document buffer on every keystroke or suggestion render.
• Xcode 16.x compatibility: Newer versions of Xcode may have subtle API or behavior changes that the Copilot plugin hasn’t accounted for yet.
• Rosetta fallback (unlikely, but possible): If any part of the extension isn't fully Apple Silicon-native, CPU usage could spike abnormally.
• UI rendering bug: Overlapping suggestion + error icons may hint at an unoptimized or broken UI update loop.

Potential Workarounds (for now)

Until GitHub ships a patch, you could try:

1. Disable inline suggestions via Copilot plugin settings (if possible) this may reduce UI redraw overhead.
2. Roll back to a previous version (0.42.x), if you have the .xcode-extension installer cached.
3. Open a GitHub Support Ticket to report the issue officially:
   👉 https://support.github.com/contact
   More reports = faster prioritization.

Suggested Next Step for GitHub Team

It would be helpful if GitHub could:

• Acknowledge whether this is a known regression
• Confirm if a fix is being worked on
• Offer a safe downgrade path or temporary workaround

If you want, I can help create a minimal diagnostic script to monitor CPU usage per extension process or help with downgrading.

Thanks again for raising this, you're helping everyone in the community by reporting it clearly.

[veewis]

even roll back is not working now, costs a lot of cpu usage

[healthia-au]

I am getting this CPU overdrive issue on Intel iMac 5K (2020) with Sequoia 15.6.1. I've had to disable it entirely as it smashes an entire CU core.

[richellis]

I enabled Install pre-releases in the Copilot for Xcode extension settings, and after downloading 0.43.139 the sluggish performance seems resolved.

[healthia-au]

Can confirm that the latest pre-release update seems to fix the issue. When is an official release going to be pushed?

[phuanggh]

0.43.140 hasn't resolved the problems I encountered

[romain-a3bc]

Rolling back to version 0.42.0 worked for me while waiting for a fix.

You can download the DMG here: https://github.com/github/CopilotForXcode/releases/tag/0.42.0.

Keep us in touch while the system lag is fixes (notification activated).

[quixoticraindrp]

Ran into this problem with 0.44.0.

Symptoms:

• Ask mode text window input would take 10-15 seconds to start appearing, and would pinwheel every few seconds. After about 30 seconds, typed characters would appear in the input box.
• After (finally) finishing typing into the input, hitting "return" would alternately spike CPU for GitHub Copilot for Xcode Extension between 100-325+%, spikes occurring about every 5-10 seconds (all wall clock time).
• Several minutes of this later, the response would start to appear, interrupted by those same 5-10 second spikes of high CPU.

Sometimes, the CPU for the extension would spike at 300+%, and then it would stop responding, force-kill in Activity Monitor would terminate process, but not resolve issues for future runs.

Rolling back to 0.42.0 resolved all issues.

Hardware:
2018 Mac mini (3.2 GHz 6-core i7) with 64 GB RAM

Software:
macOS 15.7.1
Xcode 26.0.1

[pablosarrias]

Same problem with iMac Pro M4 and 0.44.0.
I have moved downto 0.42.0