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?

ffmpeg.wasm seeks to the nearest keyframe before the given timestamp when using fast seeking. For frame-accurate extraction, use decimal seconds (e.g. 5.5 for 5.5 seconds).

Is my video uploaded during thumbnail extraction?

No. ffmpeg.wasm processes the video entirely in your browser. Nothing is sent to any server.

How fast is thumbnail extraction?

Extracting a single JPEG thumbnail is typically very fast — a few seconds even for large files. Multiple thumbnails take proportionally longer.

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?

ffmpeg.wasm supports MP4, WebM, MOV, AVI, MKV, and most other common video containers.

Video Thumbnail Generator

Extract still frames from any video at specified timestamps — no upload, completely private.

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 and wait for ffmpeg.wasm to process.
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?: ffmpeg.wasm seeks to the nearest keyframe before the given timestamp when using fast seeking. For frame-accurate extraction, use decimal seconds (e.g. 5.5 for 5.5 seconds).
Is my video uploaded during thumbnail extraction?: No. ffmpeg.wasm processes the video entirely in your browser. Nothing is sent to any server.
How fast is thumbnail extraction?: Extracting a single JPEG thumbnail is typically very fast — a few seconds even for large files. Multiple thumbnails take proportionally longer.
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?: ffmpeg.wasm supports MP4, WebM, MOV, AVI, MKV, and most other common video containers.

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