G-code preview causing browser crashes or freezing

If your browser freezes, crashes, or becomes unresponsive when viewing the G-code preview in the Cloud Slicer, this article explains why it happens and how to fix it.

Why this happens

The G-code preview renders your entire print layer-by-layer in 3D directly in your browser. This requires significant memory and processing power - and browsers don't have full access to your device's resources like native applications do.

Your browser runs in a sandboxed environment with limited memory allocation. When the preview exceeds what your browser can handle, it may freeze or crash the tab (or in some cases, the entire browser).

Common causes

• Complex models with many layers - Tall prints or prints with fine layer heights generate more G-code to render
• Lower-powered devices - Tablets, Chromebooks, and older laptops may struggle with demanding previews
• Memory pressure from other applications - Other browser tabs, video calls, or programs running in the background compete for the same resources
• High-resolution prints - Detailed prints with lots of small movements create larger G-code files

Quick fix: disable preview on this device

If you're experiencing crashes, you can disable the G-code preview for this device. You'll still be able to slice models and see print information - you just won't see the 3D preview.

After a crash:

1. The slicer will show a dialog asking if you want to disable preview
2. Click Disable preview to turn it off for this device

From your account settings:

1. Click your profile picture in the top right
2. Go to Your account → Local preferences
3. Toggle the G-code preview setting off

You can re-enable preview later if you want to try again (for example, after closing other programs or tabs).

Re-enabling preview

There are two ways to re-enable preview after disabling it:

From the slicer:

1. Slice a model as usual
2. When the "Slicing complete" popup appears, click Always preview (on this device)

From your account settings:

1. Click your profile picture in the top right
2. Go to Your account → Local preferences
3. Toggle the preview setting back on

Other things to try

If you'd prefer to keep preview enabled, these steps may help:

Free up memory

• Close unused browser tabs - especially heavy ones like YouTube, Google Docs, or social media
• Close other applications running on your device
• Restart your browser before slicing large models

Use a different browser

Some browsers handle WebGL (the technology behind the 3D preview) better than others. If you're experiencing issues:

• Chrome and Edge generally have good WebGL performance
• Try disabling browser extensions that might interfere with graphics

Reduce print complexity

If a specific model keeps causing issues:

• Try a larger layer height (fewer layers to render)
• Split very tall prints into smaller parts
• Simplify the model if possible

Still having issues?

If you've tried the above and still experience crashes, disabling the preview is the most reliable solution. The preview is a convenience feature - your sliced files and print quality are not affected by disabling it.

If you believe something else is wrong, feel free to reach out to our support team.

Updated on: 21/01/2026