Question 1

Is my video uploaded anywhere?

Accepted Answer

No. Decoding and encoding happen entirely on your device using your browser's built-in WebCodecs API. The file never leaves your computer, which also means there is no upload wait and no server file-size limit.

Question 2

Which input formats are supported?

Accepted Answer

MP4, WebM, MOV, MKV, and most common containers. Codec support depends on your browser and hardware — H.264, VP8, VP9, and AV1 are widely supported. If a file cannot be decoded, the tool tells you immediately instead of failing at the end.

Question 3

Why is conversion so fast?

Accepted Answer

The tool uses your device's hardware video encoder through the WebCodecs API — the same silicon used by video calls and screen recorders — rather than a software encoder compiled to WebAssembly. On most machines this converts faster than real-time.

Question 4

Does converting reduce quality?

Accepted Answer

Any re-encode is technically lossy, but at the High quality preset the difference is not visible for typical footage. Choose Medium or Low to trade quality for a smaller file.

Question 5

Is there a file size limit?

Accepted Answer

No hard limit — processing is local, so the practical limit is your device's memory. Multi-gigabyte files may be slow on low-end hardware.

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