Question 1

What size should a YouTube thumbnail be?

Accepted Answer

YouTube displays thumbnails at 1280×720 (16:9). We also export 640×480, 480×360 and 320×180, plus fully custom sizes.

Question 2

Is my image uploaded to a server?

Accepted Answer

No. Every resize happens locally in your browser — your image never leaves your device.

Question 3

Can I keep the aspect ratio?

Accepted Answer

Yes. The lock button keeps width and height proportional as you drag or type new values.

Question 4

What formats can I export?

Accepted Answer

JPG for the smallest file, PNG for lossless quality, and WebP for the best quality-to-size ratio.