Trim, compress and convert video and audio in your browser
Your file never leaves this tab. Audio trimming and cleanup run instantly on the browser's own decoder; video work uses FFmpeg compiled to WebAssembly, downloaded only when you ask for it.
Your file
Drop a video or audio file here
Stays on your device. Nothing is uploaded, and nothing is saved after you close the tab.
This needs the FFmpeg engine
Minutes and seconds, so 1:30 is ninety seconds. Leave the end blank to run to the end of the file.
What do you want to do?
Drops creation date, device model, GPS location and any title or comment fields from the output.
No download needed for these
Trimming, normalising, fading and WAV export all run on the browser's own audio decoder. The FFmpeg engine stays untouched.
Run
Running on your device — keep this tab open
Show the equivalent FFmpeg command
Exactly what runs here. If your file is too large for a browser tab, run this on your own machine instead — the result is identical.
Where do you run this command?
On a computer
-
Install FFmpeg once. Open your terminal and run the line for your system:
Windows
winget install ffmpegmacOSbrew install ffmpegLinuxsudo apt install ffmpeg - Open Terminal on a Mac or Linux, or PowerShell on Windows. (On Windows, press the Start button and type PowerShell.)
- Go to the folder your file is in by typing cd and then the folder name, for example:
cd Downloads - Paste the command above and press Enter. The finished file appears in the same folder.
On a phone
You cannot practically run FFmpeg on a phone — an iPhone has no way to do it at all, and Android needs the Termux app. On a phone, this page is the easier route: it does the same job right here, with no command and no installing.
Show the FFmpeg log
Every tool
Every output format
Questions
Is my file uploaded anywhere?
No. This is a static page with no backend. Your file is read into this tab's memory, processed by JavaScript and WebAssembly running on your own machine, and never sent anywhere. You can disconnect from the network after the page loads and everything except the engine download still works.
Why is there a 31 MB download for video?
Because the video work is done by FFmpeg compiled to WebAssembly, and that is how large it is. It downloads only when you ask for an operation that needs it, and your browser caches it afterwards. Audio trimming, normalising, fading and WAV export never touch it.
Why is encoding slower than on my desktop?
Two reasons. The engine is a single WebAssembly thread where a desktop FFmpeg uses every core, and it has no access to the hardware video encoder in your GPU. Expect several times the wall-clock time. The exact command is shown under every job so you can run it locally when that matters.
What is the largest file this can handle?
In practice a few hundred megabytes. FFmpeg holds the input, the output and its working set in a single WebAssembly heap, and allocation fails well before the theoretical 4 GB limit. The tool warns above 500 MB and declines above 2 GB rather than crashing the tab.
Why can it not predict the output size?
In quality-preset mode it genuinely cannot. A constant-quality encode lets the bitrate follow how hard the footage is to compress, so a slide deck and a handheld shot of leaves differ by an order of magnitude at the same setting. Target-size and bitrate modes are predictable, and are estimated properly.
Is anything saved between visits?
Your settings are — the chosen tab, format, quality and timecodes — in this browser's localStorage, on your own device. Your file is not: it would not fit, and your footage has no business persisting on disk after you close the tab. Use "Reset everything" in the footer to clear the settings.
Nothing is uploaded. There is no server to upload to — this is a static page, and every frame is processed on your own machine.