Video Converter (Local-only)

Convert video/audio locally in your browser using ffmpeg.wasm. No uploads. WorkerFS helps reduce input copying.

Convert Video / Audio (ffmpeg.wasm)

Value prop: No Cloud Upload Limits (no uploads). Reality check: very large files still depend on browser/device memory.

Input file

No file chosen

Output

Encoder availability depends on the ffmpeg.wasm build. If a conversion fails, try a different output format.

Logs

How-to Guide

Click “Load FFmpeg” to initialize (first load downloads the WASM core).
Select a video or audio file (read locally).
Choose an output format and click “Convert”.
Download the result.

Tip: for large files, close other tabs. iOS Safari has stricter memory limits and may fail more easily.

Privacy FAQ

Q: Do you upload my video/audio to a server?

A: No. Conversion runs in your browser via ffmpeg.wasm.

Q: What does “No Cloud Upload Limits” mean?

A: We don’t upload your file to a server. The bottleneck is your device memory and browser implementation—not an upload limit.

Q: What’s the technical limit for huge files?

A: WebAssembly/browser memory can become unstable around ~2GB (some environments may reach ~4GB). This page uses WorkerFS to reduce input copying, but the output still needs memory.

Technical Explanation (WorkerFS)

A naive approach copies the full input into WASM memory before processing. WorkerFS can mount the browser File object as a readable file so ffmpeg can read more like streaming, reducing peak memory from input copying.

Note: this does not mean unlimited size. The output still lands in an in-memory filesystem, and large outputs consume a lot of memory.

Related guides (Wiki)

Understand common formats and pick the right output for compatibility.

.MOV guide All extensions (Wiki)