Convert Video Format
Convert between MP4, WebM, MOV, and AVI video formats instantly. Free, private, and entirely browser-based — your files never leave your device.
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Supports MP4, WebM, MOV, AVI — up to 500 MB
Format comparison guide
MP4 (H.264)
The most widely compatible format. Works on virtually every device, browser, and platform. Best choice for sharing.
WebM (VP8)
Open format optimized for the web. Smaller files than MP4 at similar quality. Supported by Chrome, Firefox, and Edge.
MOV (H.264)
Apple’s preferred format. Best for editing on macOS and iOS devices with iMovie, Final Cut Pro, and QuickTime.
AVI (MPEG-4)
Legacy format with broad desktop support. Larger files, but useful when working with older software or hardware.
How to convert video files online
Video format compatibility is one of the most common friction points when sharing files across devices and platforms. An MP4 recorded on your phone may need to be WebM for a website, MOV for an Apple workflow, or AVI for legacy software. This free converter handles all four formats with high-quality re-encoding and minimal quality loss.
The tool uses FFmpeg WebAssembly to re-encode your video directly in the browser. Each format uses optimized encoding settings: H.264 + AAC for MP4 and MOV, VP8 + Vorbis for WebM, and MPEG-4 + MP3 for AVI. The result is a fully compatible file in your chosen format.
All processing runs entirely in your browser using WebAssembly. Your video files are never uploaded to any server, ensuring complete privacy. The first conversion requires a one-time download of the FFmpeg engine (~30 MB), after which subsequent conversions start immediately.
Frequently asked questions
Why would I need to convert video formats?
Different platforms and devices prefer different formats. MP4 is the most universal, but WebM is better for web embedding, MOV is preferred on Apple devices, and some older systems require AVI.
Will converting my video reduce quality?
The tool re-encodes the video using high-quality settings to preserve as much quality as possible. Some minimal quality difference may occur due to re-encoding, but it should be imperceptible for most use cases.
What formats are supported?
You can convert between MP4, WebM, MOV, and AVI. The tool accepts any of these as input and can output to any of the four formats.
How fast is the conversion?
Speed depends on file size and length. A 30-second 1080p video typically converts in 15–45 seconds. The first conversion requires downloading the video engine (~30 MB one-time).
Is my video uploaded to a server?
No. All conversion happens locally in your browser using WebAssembly (FFmpeg.wasm). Your files never leave your device.