How Video Format Comparison Works

Upload once — compare file sizes for VP9, VP8, and AVC side by side, then download the best for your use case.

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Step-by-step process

  1. 1

    Three sequential encodes

    Your video is encoded three times — once for VP9, VP8, and AVC (H.264). Each encode plays the video through in real time. The three passes happen one after another, so total processing is approximately 3× the video duration.

  2. 2

    File size measurement

    Each output blob is measured and displayed with its file size, a size bar relative to the source, and the percentage difference. The format with the best compression for your specific video content is highlighted.

  3. 3

    Download any format

    Each format has its own download button. Download the one that gives the best size for your target platform, or download all three for comparison.

100% private by design. All processing runs in your browser — your files never leave your device. No account required.

Frequently asked questions

Which codec should I choose for web delivery?

VP9 (WebM) typically gives the best compression for streaming and web use, and is supported by all modern browsers. Use H.264 (MP4) for maximum device compatibility — phones, smart TVs, and older software may not support VP9.

Why is AVC/H.264 greyed out?

H.264 encoding is not supported by all browsers via MediaRecorder. Firefox, for example, does not support it. Chrome and Edge do.

How is this different from the Video Compressor?

The Format Comparison tool shows you the natural size of each format at default browser quality settings. The Video Compressor lets you target a specific bitrate/quality level within one format (VP9).

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