Video Thumbnail Generator
Create preview images and contact sheets from your videos directly in the browser, choosing time, format and resolution, all fully local on your device.
Your inputs are processed in your browser and are not transmitted to our servers. Note: third-party resources (e.g. advertising and analytics from Google/Cloudflare) and an optional PayPal donation link may transfer data when loading or when clicked. Browser extensions or plugins may be able to read content that is visible in the input fields.
The result will appear here …
How to use this tool (video)
This video is hosted on YouTube. When you play it, data may be sent to Google.
Video Thumbnail Generator – Preview Images and Contact Sheets in the Browser
Create preview images and contact sheets from your videos directly in your browser. Choose a time point, format, and resolution, and the tool works entirely locally on your device. Your videos are never uploaded.
Single frame at a specific time
In single-frame mode, pick a time as a percentage and choose your output format. The tool finds the nearest keyframe and exports it as JPEG, PNG, or WebP. Optionally limit the maximum width in pixels so the image scales down without manual cropping.
Contact sheet across the full duration
The contact sheet mode distributes frames evenly across the video duration and arranges them in a grid. You set the columns and rows. A quick visual overview of the video content at a glance – useful for editing, curation, or archiving.
Formats and resolution
Choose from JPEG, PNG, or WebP. JPEG gives the smallest files with acceptable quality, PNG offers lossless copies, and WebP provides a good quality-to-size ratio. The optional max width limit helps avoid overly large images for web pages.
Privacy and local processing
All processing happens directly in your browser. No frame, preview image, or metadata is sent to a server. The video is loaded, processed, and the canvas output stays on your device. When you close the tab, temporary object URLs are revoked automatically.
Frequently asked questions
How is the single-frame preview created?
The video is decoded locally in the browser. The slider sets a time point as a percentage of total duration. The tool finds the nearest keyframe and draws the current frame onto a canvas, which is then exported as an image.
What output formats are supported?
You can choose JPEG, PNG, or WebP. JPEG is the most compact option, PNG provides lossless quality, and WebP offers a good balance of quality and file size.
What is the difference between single frame and contact sheet?
Single frame creates one image at a chosen time point. Contact sheet distributes multiple frames evenly across the video duration and arranges them in a grid.
Can I reduce the image size on export?
Yes. In single-frame mode you can enter a maximum width in pixels. The tool scales proportionally down, never up. Contact sheet thumbnails stay fixed at 240×135 pixels per cell.
Where do the frames for the contact sheet come from?
Frames are extracted evenly across the entire video duration. For a 4×3 contact sheet with 12 frames, time points fall at 0%, 8.3%, 16.7% and so on up to 100%.
Are my video files saved or transmitted?
No. Everything runs locally in the browser. The video file is loaded via an object URL and temporary resources are revoked after processing. No data is sent to any server.