Free Video Tools
Convert and trim video right in your browser — free, no sign-up, no watermark. Every tool runs on your own device with ffmpeg (WebAssembly), so your files are never uploaded. Free on LK Forge — no sign-up.
What are the LK Forge video tools?
LK Forge Video Tools is a suite of browser-based video tools that run ffmpeg compiled to WebAssembly on your own device, so no file is ever uploaded. The suite converts MOV, MKV, WebM and AVI to MP4 (H.264 video at CRF 23, AAC audio at 160 kbps, written with faststart so playback can begin before the download finishes), turns an MP4 into an animated GIF at 8-20 fps and 320-800 px wide using a two-pass colour palette, converts a GIF to MP4, remuxes MP4 to MOV losslessly with -c copy, and trims a clip without re-encoding it. The engine is a single-threaded WebAssembly build of ffmpeg shipped as a 9.75 MiB gzip and downloaded once per session, on your first conversion. There is no watermark, no account and no queue. Nothing you load is uploaded, logged or stored, and closing the tab clears it all; the tools need a connection only for that one-time engine download.
Convert to MP4 — plays everywhere
MOV to MP4
Convert QuickTime MOV to a playable MP4.
MKV to MP4
Convert Matroska MKV to a playable MP4.
WebM to MP4
Convert WebM to MP4 for editors and uploads.
AVI to MP4
Convert legacy AVI to a modern, smaller MP4.
GIF to MP4
Shrink an animated GIF into a small MP4.
GIF to Video
Convert an animated GIF into a video file (MP4).
Edit & other formats
Private, in-browser video conversion
Most online converters upload your video to a server, queue it, watermark it, or cap the file size. These don’t. The moment the page loads, everything happens locally: you pick a file, it’s read straight into a video engine running inside your browser tab, and the converted result appears for download — the video data never leaves your device. That makes these tools safe for personal recordings and work files, and it means there is no upload wait and no sign-up. The trade-off is that your own device does the work, so very large or long clips take longer than a big server would; for those, trim to what you need first with the Video Trimmer.
Under the hood every tool runs ffmpeg compiled to WebAssembly (ffmpeg.wasm) — the same engine behind most desktop video software, running as code inside your browser rather than on a remote machine. That is what lets the suite convert between real containers and codecs instead of just renaming a file: converting MOV, MKV, WebM and AVI into an MP4 that plays on phones, editors and social sites; turning a clip into an animated GIF or shrinking a GIF back into a small MP4; and remuxing MP4 to MOV for Apple apps without re-encoding.
Because the whole pipeline is client-side JavaScript and WebAssembly, there is nothing to install, no extension to add and no key to paste — open a tool, drop in a file, and download the result. The first conversion in a session loads the ffmpeg engine, so it may take a few seconds; after that, repeat conversions are quick. Everything is free, private and works on desktop, tablet and mobile, with the only real limit being the memory available on the device doing the work.
Which tool do I need?
Three kinds of job — and only two of these tools keep the file bit-for-bit identical.
| Tool | In | Out | Method | Quality | Speed |
|---|---|---|---|---|---|
| MOV to MP4 | .mov (H.264 / HEVC / ProRes) | .mp4 H.264 + AAC | Re-encode, CRF 23 | Near-identical | Slowest |
| MKV to MP4 | .mkv, any codec | .mp4 H.264 + AAC | Re-encode, CRF 23 | Near-identical | Slowest |
| WebM to MP4 | .webm VP8 / VP9 / AV1 | .mp4 H.264 + AAC | Re-encode, CRF 23 | Near-identical | Slow |
| AVI to MP4 | .avi, legacy codecs | .mp4 H.264 + AAC | Re-encode, CRF 23 | Usually improves size | Slow |
| MP4 to MOV | .mp4 H.264 + AAC | .mov, same streams | Remux (stream copy) | Bit-for-bit identical | Seconds |
| Video Trimmer | Any video | Same format, cut | Remux (stream copy) | Bit-for-bit identical | Seconds |
| MP4 to GIF | .mp4 | .gif, 256 colours | Two-pass palette | Palette-limited | Moderate |
| GIF to MP4 | .gif | .mp4 H.264, silent | Re-encode, CRF 23 | Usually several times smaller | Fast |
| GIF to Video | .gif | .mp4 H.264, silent | Re-encode, CRF 23 | Usually several times smaller | Fast |
The two remux tools — MP4 to MOV and the Video Trimmer — copy the existing video and audio streams rather than decoding them, so they finish in seconds regardless of file length and lose nothing at all. Every other tool decodes and re-encodes, which is why a long 4K file takes real time on your own hardware.