Is my video uploaded to a server?

No. It is processed entirely in your browser by ffmpeg compiled to WebAssembly (ffmpeg.wasm), so the file never leaves your device and there is no server-imposed size cap. The trade-off is that your own CPU does the work, so it is best for short clips.

Why is the first conversion slow to start?

The ffmpeg engine is a one-time WebAssembly download that loads on your first run and is then cached for later. After that, a progress percentage shows how far the encode has gotten.

What settings does the GIF export use?

GIF is fixed at 10 fps and downscaled to 480 px wide with the aspect ratio preserved, a deliberate default that keeps the file size reasonable. Note that GIF has no audio and only 256 colors, so smooth gradients may band.

How do I extract just the audio from a video?

Choose MP3 as the output. It discards the video and saves only the audio track as an MP3 at a high-quality variable bitrate, which is handy for pulling audio out of a talk, lecture, or music video.

Can I trim or resize the video here?

Not directly. MP4 and WebM output keeps the source resolution and there is no trim control (only GIF is downscaled). To cut out a segment, use the Video Editor, which copies streams without re-encoding for a fast, lossless cut; if a large file stalls, trim it smaller first.

Video Converter

Convert between video formats.

Video is processed in your browser with ffmpeg.wasm — large files take a while and use memory.

Choose a videoOutput format

Choose a video file.

What is Video Converter?

Video Converter is a free tool that converts video to MP4, WebM, GIF, or MP3 entirely in your browser, powered by ffmpeg.wasm. Re-encode between formats, turn a clip into an animated GIF, or extract just the audio track — best suited to short clips.

Key features

Outputs MP4, WebM, animated GIF, or MP3 audio
GIF export downscales to 480 px at 10 fps
MP3 mode extracts only the audio track
Shows progress while it processes
Powered by ffmpeg.wasm — engine loads once on first run

How to convert a video format

Most "free video converter" sites upload your clip to a server, process it there, and make you wait in a queue. This tool runs ffmpeg — the same engine behind nearly every professional video pipeline — compiled to WebAssembly so it executes inside your browser tab. Your video never leaves your device, there's no upload wait and no file-size cap imposed by a server, but the flip side is that the work happens on your CPU, so speed depends on your machine and it's best kept to short clips.

How to use it

Choose a video. Any format your browser can hand to ffmpeg works as input.
Pick an output format (details below).
Convert & download. The first run downloads the ffmpeg engine once (a one-time WebAssembly download that's then cached), so the first conversion takes longer to start; a percentage progress bar shows how far along the encode is.

The four output modes

MP4 — re-encodes to the most universally compatible video format. This is the safe default for sharing a clip that needs to play anywhere — phones, editors, social platforms.
WebM — an open, royalty-free format that tends to produce smaller files at similar quality, ideal for embedding on a website with an HTML <video> tag.
GIF — turns a clip into a looping animated GIF. It's fixed at 10 fps and downscaled to 480 px wide (aspect ratio preserved), which keeps the file sane — an unconstrained GIF of video is enormous. Great for a short reaction loop or a silent demo, but GIF has no sound and only 256 colors, so gradients will band.
MP3 — discards the video entirely and extracts just the audio track as an MP3, using a high-quality variable bitrate. Perfect for grabbing the audio from a talk, a lecture, or a music video.

Why in-browser processing has trade-offs

Because ffmpeg is running as WebAssembly on your own hardware, a conversion that a data-center server finishes in seconds may take noticeably longer here, and a very large or long file can exhaust the tab's available memory and fail. The realistic sweet spot is clips measured in seconds to a couple of minutes. If a big file stalls, trim it down first or convert a shorter section.

Tips and limits

This tool doesn't trim or resize (except GIF). MP4 and WebM output keeps the source resolution. To cut a segment out of a clip, use the dedicated Video Editor, which copies streams without re-encoding for a fast, lossless cut.
GIF settings are fixed. You can't change the 480 px width or 10 fps here — that's a deliberate, sensible default for shareable GIFs rather than a knob to tune.
Keep the tab in the foreground. Heavy WebAssembly work can be throttled by the browser in a background tab, so leave the page visible while it processes.
Nothing is uploaded, ever. The entire re-encode runs locally through ffmpeg.wasm; the only network activity is that one-time engine download on your first conversion.

Frequently asked questions

Is my video uploaded to a server?: No. It is processed entirely in your browser by ffmpeg compiled to WebAssembly (ffmpeg.wasm), so the file never leaves your device and there is no server-imposed size cap. The trade-off is that your own CPU does the work, so it is best for short clips.
Why is the first conversion slow to start?: The ffmpeg engine is a one-time WebAssembly download that loads on your first run and is then cached for later. After that, a progress percentage shows how far the encode has gotten.
What settings does the GIF export use?: GIF is fixed at 10 fps and downscaled to 480 px wide with the aspect ratio preserved, a deliberate default that keeps the file size reasonable. Note that GIF has no audio and only 256 colors, so smooth gradients may band.
How do I extract just the audio from a video?: Choose MP3 as the output. It discards the video and saves only the audio track as an MP3 at a high-quality variable bitrate, which is handy for pulling audio out of a talk, lecture, or music video.
Can I trim or resize the video here?: Not directly. MP4 and WebM output keeps the source resolution and there is no trim control (only GIF is downscaled). To cut out a segment, use the Video Editor, which copies streams without re-encoding for a fast, lossless cut; if a large file stalls, trim it smaller first.

Privacy

ffmpeg.wasm runs the entire re-encode inside your browser tab; the video file is never uploaded, though this also means processing time depends on your device.