Audio & Video Tools
Real FFmpeg — the same encoder used by broadcast pipelines — running inside your browser through WebAssembly. Trim, convert, compress and extract without uploading a single frame.
Media Info (ffprobe)
Container, codecs, resolution, frame rate, bitrate, duration and every stream — read with ffprobe.
Video Converter
MP4, WebM, MOV, MKV and AVI to one another — container, codec, resolution and quality under your control.
Video Compressor
Shrink MP4, WebM and MOV with CRF and resolution control — see the before/after size without uploading a byte.
Video Trimmer
Cut a clip down to the seconds you need — instant stream-copy trimming, or frame-accurate re-encoding.
Video to GIF
A video clip into a looping GIF or animated WebP — frame rate, width and a two-pass palette for clean colour.
Extract Audio from Video
Pull the soundtrack out of an MP4, MOV, MKV or WebM as MP3, WAV, AAC or OGG — no re-encode when the codec fits.
Audio Converter
Between MP3, WAV, OGG, AAC, M4A and FLAC — with bitrate, sample rate and channel control.
Why run FFmpeg in the browser?
Every other online video converter works the same way: you upload a file, wait, and a server somewhere transcodes it. That means your footage — a client interview, an unreleased product demo, a private recording — sits on someone else's disk, and you pay for it in upload time before the work even starts. On a slow connection that upload is often slower than the encode itself.
BasaltKit compiles FFmpeg to WebAssembly and runs it in a worker thread inside this tab. The file you pick is read straight from your disk, decoded, re-encoded and written back to a download — it never touches a network. There is no file-size limit, no queue, no watermark and nothing to sign up for. Once the engine is cached you can even disconnect and keep going.
What it can and cannot do
The engine is a full build of FFmpeg 5.1 with x264, x265, libvpx (VP8/VP9), libmp3lame, Opus, Vorbis, Theora, WebP, libass and FreeType linked in — so H.264, HEVC, VP9, MP3, AAC, FLAC, WAV, OGG, MP4, MKV, WebM and friends are all available. Two things it does not have are hardware acceleration and native SIMD, which is the honest reason a WebAssembly encode runs several times slower than the same command in a terminal. That is why we lean on fast paths: trimming and audio extraction copy the existing streams instead of decoding them, so a cut costs seconds rather than minutes.
Where to start
Not sure what you are working with? Run the file through Media Info first — it reports the container, codec, resolution, bitrate and duration, which tells you whether a job needs a re-encode at all. Video Compressor is usually the next stop for anything headed to the web, and Video to GIF handles the short loops people actually paste into chat.