Drop your own Short. It suggests three crisp frames; you can scrub to any other.
The cover a viewer sees on your channel's Shorts tab is a frame of the video, and a blurred mid-motion frame looks like a mistake. This tool measures focus across the clip, puts the three sharpest moments in front of you, and opens your pick in the editor at 1080x1920 so you can add a title. Your video stays on your device.
Drop or click to choose
A vertical video works best; a 16:9 one is cropped to 9:16
MP4, WebM or MOV your browser can play. Up to 10 minutes and 2 GB.
The three sharpest frames
Measuring focus across the clip...
Or scrub to any frame
Your video is wider than 9:16, so the cover is cropped from it. Slide to choose which part.
Your cover, 1080x1920
The safe-zone overlay is a guide on this page only; it is never drawn into the image.
Choose the vertical video you are about to post. It is read by your browser's own player and never sent anywhere.
The three sharpest moments appear first. Tap one, or drag the slider and step frame by frame to the expression you want.
The overlay shows where the player's buttons and title sit, so the face and the words you add stay in the clear middle.
One tap opens the frame in the editor on a 1080x1920 canvas. Add a title, a sticker or an arrow, then download.
The scan samples the clip evenly, about six frames a second of video with a ceiling of 90 samples, and scores each one on focus: the variance of a Laplacian edge filter on a small grey copy of the frame. A crisp frame has hard brightness steps at its edges and scores high; motion blur and soft focus score low. Frames that are nearly flat, a fade or a cut to black, are set aside. The three picks are kept apart in time so you get three different moments, not three neighbouring frames. It judges clarity only. It cannot tell a good expression from a bad one, which is why the scrubber is right there.
On a channel's Shorts tab and in some feeds the frame is shown in a tall card, often cropped closer than the full 9:16. Keep the subject near the middle, and keep any title out of the bottom quarter, where the video's own title and channel name are drawn.
Keep going: your cover carries over to the next tool with no re-upload.