What format are the thumbnails?

Thumbnails are exported as JPEG images at the full native video resolution. JPEG provides a good balance of quality and file size for preview images.

Can I extract thumbnails from multiple timestamps at once?

Yes. Enter multiple timestamps separated by commas (e.g. 0, 5, 10, 30) and the tool will extract one frame per timestamp. Each is downloaded separately.

How precise are the timestamps?

The tool seeks the HTML5 video element to the requested time and draws the displayed frame to a canvas. Precision matches whatever your browser exposes to playback — typically within a few hundredths of a second. Decimal seconds (e.g. 5.5) work for sub-second targets.

Is my video uploaded during thumbnail extraction?

No. The whole pipeline — decode, seek, draw, JPEG encode — runs in your browser via the native element and a canvas. Nothing is sent to any server.

How fast is thumbnail extraction?

Each thumbnail finishes in a fraction of a second. There is no WASM loader and no encoder — your browser already decoded the frame for playback, we just snap it.

Can I choose the thumbnail resolution?

The thumbnail is exported at the original video resolution. To resize it, use the Image Resizer at /resize/ after downloading.

What is the difference between thumbnails and frame extraction?

The Thumbnail Generator targets specific timestamps (e.g. the 5-second mark). The Frame Extractor at /video/frames/ captures frames at a regular interval across the whole video.

Which input video formats are supported?

Whatever your browser can play natively. Chrome, Edge, and Firefox handle MP4 (H.264/H.265/AV1), WebM (VP9/AV1), and Ogg out of the box. Safari adds HEVC and some QuickTime variants. If the video plays inside our preview window, the thumbnail tool can extract from it.

サムネイル生成

任意のタイムスタンプで動画のスチルフレームを抽出してJPEGでダウンロード。

100% client-side · no upload

Video file (MP4, WebM, MOV…)

Load a video file to begin.

How to generate video thumbnails

Select your video file. MP4 and WebM are best supported.
Enter the timestamps (in seconds) where you want thumbnails. You can enter multiple separated by commas.
Click Extract thumbnails — frames are decoded by your browser's built-in video pipeline.
Click each thumbnail image to download it as a JPEG.

Common use cases

YouTube covers: Extract the best frame from a video to use as a custom thumbnail.
Video previews: Generate a grid of thumbnails to give viewers a quick visual preview of a long video.
Social media: Pick a striking frame as the cover image for a video post on Instagram or LinkedIn.
Documentation: Capture specific frames from a screen recording to use as screenshots in a guide.

Related tools: Frame Extractor · Video Trimmer · Video to GIF · Image Resizer

よくある質問

What format are the thumbnails?: Thumbnails are exported as JPEG images at the full native video resolution. JPEG provides a good balance of quality and file size for preview images.
Can I extract thumbnails from multiple timestamps at once?: Yes. Enter multiple timestamps separated by commas (e.g. 0, 5, 10, 30) and the tool will extract one frame per timestamp. Each is downloaded separately.
How precise are the timestamps?: The tool seeks the HTML5 video element to the requested time and draws the displayed frame to a canvas. Precision matches whatever your browser exposes to playback — typically within a few hundredths of a second. Decimal seconds (e.g. 5.5) work for sub-second targets.
Is my video uploaded during thumbnail extraction?: No. The whole pipeline — decode, seek, draw, JPEG encode — runs in your browser via the native <video> element and a canvas. Nothing is sent to any server.
How fast is thumbnail extraction?: Each thumbnail finishes in a fraction of a second. There is no WASM loader and no encoder — your browser already decoded the frame for playback, we just snap it.
Can I choose the thumbnail resolution?: The thumbnail is exported at the original video resolution. To resize it, use the Image Resizer at /resize/ after downloading.
What is the difference between thumbnails and frame extraction?: The Thumbnail Generator targets specific timestamps (e.g. the 5-second mark). The Frame Extractor at /video/frames/ captures frames at a regular interval across the whole video.
Which input video formats are supported?: Whatever your browser can play natively. Chrome, Edge, and Firefox handle MP4 (H.264/H.265/AV1), WebM (VP9/AV1), and Ogg out of the box. Safari adds HEVC and some QuickTime variants. If the video plays inside our preview window, the thumbnail tool can extract from it.

Last updated: 2026-05-20 By jarvisbox

このツールの問題を報告