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If the editor is slow, switch the editing quality below the video to Low-res. If the editor shows a preview error instead of your video, follow the fix it suggests (usually turning on hardware acceleration or updating your browser), then click Try again. Your video and edits are safe either way.

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Why does the editor show an error instead of my video?

The editor uses your computer’s graphics processor to render the video preview, through a browser feature called WebGPU. If the preview cannot start or stops working, Tella replaces it with an explanation and recovery options. Find the title you see:
Your original video and edits are safe when the preview fails. You can still watch the video from its share page.

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Why is the editor slow or not opening?

Check the editing quality button in the toolbar below the video and switch it to Low-res (fastest). It plays small copies of your clips while you edit, and sharing and export still use full quality. It’s on by default, so this mostly matters if you switched to Hi-res or Source. See Edit faster with low-res mode. If you see This editor is running slowly on this device or Your browser is rendering this editor without a GPU, turn on hardware acceleration in your browser settings, update your graphics drivers, or close other tabs. Low-res mode does not replace the browser’s graphics requirements. If hardware acceleration is already on, see WebGPU is hardware accelerated but the error is still there.
Last modified on October 22, 2026