Is my video uploaded to a server?
No. Decoding, trimming, and audio encoding all run inside your browser using the WebCodecs API. The file never leaves your device. URL mode fetches the remote file directly into your browser when CORS allows it.
Which audio formats can I export?
MP3, WAV, FLAC, OGG (Vorbis), Opus, AAC (ADTS), and M4A (AAC inside MP4). Available formats are detected at runtime — codecs your browser cannot encode are greyed out in the format dropdown.
Which format should I pick?
Pick MP3 for maximum compatibility, AAC/M4A for Apple devices, Opus for the smallest file at the same perceived quality, FLAC or WAV when you need a lossless master, and OGG (Vorbis) for open-source tooling.
What does Audio quality mean for lossless formats?
Nothing. Bitrate is ignored for WAV and FLAC because they are lossless — every audio sample is preserved bit-for-bit. The quality dropdown disables itself automatically when a lossless format is selected.
Why is one of the formats greyed out?
Your browser does not expose an encoder for that codec. MP3 encoding in particular is not native in some browsers. Use Chrome or Edge for the broadest codec coverage, or pick another format from the list.
What is the maximum file size?
2 GB per video. The waveform and conversion stream samples through memory rather than buffering the whole file, so trimming a long recording stays responsive.
Why does my video have no audio track?
Some recordings (silent screen captures, GIF-derived MP4s, muted exports) have no audio stream. The tool detects this on import and disables conversion. Add an audio track upstream before converting.
Can I trim with millisecond precision?
Yes. Drag the handles on the waveform for fast trimming, or type into the Start and End fields using HH:MM:SS.mmm — values are clamped to the video duration and honoured to the millisecond.