OneTaskBy Tim King · Updated
Video Cover Frame Picker
Eight Sharp Frame Suggestions, Frame-by-Frame Stepping and JPEG, PNG or WebP Export
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How the Video Cover Frame Picker works
This video cover frame picker helps you choose the one frame that sells a video. Press Suggest frames for eight sharp, well-exposed candidates, or drag Position and step frame by frame. Save the frame as a JPEG, PNG or WebP cover image. Nothing leaves your browser.
The cover frame is the first thing anyone sees. Upload sites, social feeds and chat apps pick one for you, often the first frame or a random one, and that frame is too often a blink, a blur or a black fade. Choosing it yourself is the cheapest improvement you can make to a video.
How the video cover frame picker scores frames
Suggest frames samples 40 points evenly through the clip at a small size. Each is scored for sharpness, using the variance of a Laplacian edge filter on the green channel, which is high for crisp detail and low for motion blur or focus hunting. The score is then weighted by exposure, so frames whose average brightness is far from mid-grey, such as fades and blown skies, sink down the list.
The eight best are kept, with a rule that no two are closer than one twentieth of the clip, so you get eight different moments instead of eight copies of the same sharp shot. Click any thumbnail to jump there.
Sizes and formats
| Size | Use for |
|---|---|
| Original | Keeps the video's own resolution |
| 1920 × 1080 | YouTube custom thumbnails, 16:9 players |
| 1280 × 720 | YouTube's minimum, faster uploads |
| 640 × 360 | Email, chat previews, the HTML poster attribute |
The fixed sizes are 16:9 and fill the frame, so a vertical or square video is cropped from the centre. Choose Original to keep the whole picture. JPEG is the safe choice for photos and every upload form. PNG is lossless and suits screen recordings with text. WebP is about a third smaller than JPEG and works in every modern browser.
Tips and pitfalls
Look for eyes open and faces turned in. The scoring finds sharp frames, not flattering ones. Check the suggestions for blinks and half-spoken words, then step a frame or two either way.
Avoid frames with text you will cover. Platforms lay play buttons, durations and titles over the corners and bottom of a thumbnail.
Previous and Next step by 1/30 s. That is one frame at 30 fps. At 60 fps every second press lands on a new frame; at 24 fps some presses show the same frame.
How to read the result
The stats show the time of the chosen frame, the image size, the format and the file size. Every change to Position, Size or Format updates the image ready to download.
FAQ
How do I choose a thumbnail from a video?
Open the video here and press Suggest frames. Eight sharp, well-exposed frames appear below the picture. Click the one you like, fine-tune it with Previous and Next frame, then Download it as an image to upload as your cover.
What size should a video thumbnail be?
For YouTube use 1280 × 720 or larger at 16:9, under 2 MB as JPEG or PNG. Most social platforms pick the cover from the video frame size, so Original is right for vertical clips meant for Reels, Shorts or TikTok.
Why are some suggested frames similar?
The tool keeps suggestions at least one twentieth of the clip apart. A long, static shot can still produce several near-identical moments if it is the sharpest part of the video. Drag Position to explore other parts.
Is my video uploaded to pick a frame?
No. Frames are decoded, scored and saved by your own browser on your device. The video is never sent to a server, so you can choose covers for private or unreleased videos without any risk.
See also: all Video & Screen tools, Images, Audio, PDF, SVG, Simulations & Screensavers, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
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