How to use the YouTube thumbnail resizer
- Drop your photo into the box above.
- Drag the frame to choose what stays in the picture (or choose Fit to keep everything).
- Download the finished image.
Why GlideConvert?
- Private by design. Your files are converted on your own device by your browser — they are never uploaded to a server. That keeps them private, avoids upload waits and means there is no queue.
- Fast. Images convert in a fraction of a second; video uses your device’s hardware encoder.
- Free. No sign-up, no watermark. 10 images, 5 audio files or one video at a time — Pro lifts the limits and removes ads.
Frequently asked questions
What size should a YouTube thumbnail be?
YouTube recommends 1280×720 pixels (16:9, minimum width 640 px) as JPG, PNG or GIF, under 2 MB. This tool crops your image to 16:9, resizes it to 1280×720 and keeps it under 2 MB.
Why is my thumbnail rejected?
Usually because it is over 2 MB or the wrong aspect ratio. The output here is always 16:9 and below the size limit.
Are my files uploaded to a server?
No. GlideConvert runs entirely in your browser: images are processed with the browser’s built-in codecs and WebAssembly, video and audio with hardware-accelerated WebCodecs (or a WebAssembly build of FFmpeg for older formats). Nothing is sent anywhere — you can even disconnect from the internet once the page has loaded.