Convert video files
Convert a video from one format to another without uploading it anywhere. Drop in your file, choose MP4 or WebM, and In1 re-encodes it in your browser. Best for short clips, since conversion runs on your device.
How to use Video Converter
- 1
Add your video
Drag a video file into the drop area, or click to choose one from your device.
- 2
Choose a format
Pick MP4 (H.264) for maximum compatibility, or WebM for a smaller web-friendly file.
- 3
Convert
Click convert and In1 re-encodes the video locally. The first run loads the engine.
- 4
Download
Save the converted video. Your file was never uploaded anywhere.
Convert between MP4 and WebM
Video formats are not interchangeable, and the one you have is not always the one a particular site, app or editor will accept. MP4 (with H.264 video) is the universal standard that plays virtually everywhere — phones, browsers, editors, social platforms and TVs — which makes it the safest choice for sharing and compatibility. WebM is a free, open format designed for the web that often produces smaller files and is preferred by some web apps and platforms. In1 converts between the two so you can take a WebM that will not open in your editor and turn it into an MP4, or convert an MP4 into a lighter WebM for embedding on a page. You simply pick the output format and the tool re-encodes the video for you. Because both formats are widely supported, having a quick way to move between them means you are never blocked by a file that is technically fine but in the wrong container.
Runs in your browser — private and free
The conversion happens entirely on your own device using ffmpeg compiled to WebAssembly, so your video is never uploaded to a server, stored or logged. That matters because video is often deeply personal — recordings of family and friends, screen captures that may contain private details, or footage that simply is not meant to be public. Most online converters send your file to their servers to process it; In1 does not, which removes that privacy risk entirely. There is no account, no watermark on the output and no daily limit. The trade-off for keeping everything local is that re-encoding video is computationally heavy and runs on your device, so this is best suited to short clips rather than feature-length files. For the typical clip you want to convert, though, it gives you the convenience of an online tool with the privacy of an offline one, and nothing ever leaves your machine.
Honest about performance
It is worth being upfront: re-encoding a video is fundamentally more demanding than converting an image or extracting audio, and In1 runs the encoder in a single thread to keep the site fast and compatible with the ads that keep it free. The practical effect is that conversion speed depends on your device and the length of the clip — a few seconds of video convert quickly, while a long recording can take a while. To keep things responsive and avoid running out of memory, there is a sensible size limit on the file you can load, and very large or long videos are better handled by a desktop application. We use a fast encoder preset so the wait stays reasonable, and a progress bar keeps you informed throughout. Setting expectations here means you can decide when the in-browser convenience is the right call and when a heavier file belongs in dedicated software. For most short clips, the local approach is more than fast enough and well worth the privacy it buys.
The first conversion loads the engine
Because the encoder runs locally, the ffmpeg core downloads to your browser the first time you use a video or audio tool here. It happens once and is then cached, so later conversions start much faster and even work offline. While the engine loads and while your video is being re-encoded, a progress indicator shows that the tool is working and has not stalled. None of this requires any setup from you — it is simply what makes private, on-device video conversion possible without installing anything. Once the core is cached, the only time cost is the encoding itself, which depends on the clip. This one-time download is also why the very first conversion feels slower than the ones that follow: after it, the engine is ready and waiting, so you can convert several clips in a row without paying that cost again.
Who converts video and why
The need is common. People convert a WebM downloaded from the web into MP4 so it opens in their phone's gallery or a video editor that does not support WebM. Others convert an MP4 into WebM to embed it on a website with a smaller file size. Someone whose camera or screen recorder produced a format an upload form rejects converts it into a widely accepted one. Developers convert clips into the format a platform or player expects. Anyone who has hit 'this video format is not supported' has needed a converter. In every case the goal is the same: take the video you have and turn it into a format that works where you need it, at a reasonable quality — and, with In1, do it privately on your own device and for free, without sending personal footage to a server or installing heavy software for an occasional conversion. As a rule of thumb, reach for MP4 when you need something that will play anywhere without question, and choose WebM when a smaller, web-optimized file is the priority and you know the destination supports it.
Higher limits, batch processing and an API are on the way. Want early access?