How to use Trim video or audio
- Choose a video or audio file: MP4, MOV, WebM, MP3, WAV, M4A, OGG or FLAC.
- Set the start and end, by typing them or by pausing the player and taking its position.
- Leave exact cut off for an instant, lossless trim, or turn it on to cut exactly to the frame.
- Select Trim, check the result and download it.
Cut a clip in seconds, on your device
Most recordings have something to lose at the start or the end: the fumble with the record button, the silence before a talk begins, the minute after the point was made. This tool cuts a video or audio file down to the part between two times you choose. Type the times, or pause the player where you want to cut and take its position.
The file is trimmed inside your browser by FFmpeg. It is never uploaded, which matters for recordings of meetings, children, patients or anything else you would not hand to a stranger's server. The engine downloads once from WeaveAI's own engine server and your browser keeps it.
Instant and lossless, or exact
By default the trim copies the chosen part of the file as it is, without re-encoding. That makes it nearly instant even for a long file, and the quality is identical to the original because not a single frame is changed. Audio cuts land where you asked. Video has one catch: compressed video stores a full picture, a keyframe, only every second or two, and a copied clip has to begin on one, so it starts on the nearest keyframe at or before your start time.
When the cut has to be exact, for a clip that must start on a particular word or frame, turn on the exact cut. The chosen part is then re-encoded by your browser's own video encoder at high quality, so it starts and ends precisely on your times. It takes about as long as the clip plays, often less.
Formats and limits
It works with MP4, MOV, WebM and MKV video and with MP3, WAV, M4A, AAC, OGG, Opus and FLAC audio, and the trimmed file keeps the original format. Because only a part of the file is written, long recordings trim comfortably; files above about 500 MB can still run out of browser memory on phones or with many tabs open, and the tool warns you before it starts.
Questions
- Is my video uploaded?
- No. The file is trimmed inside your browser by FFmpeg, or by your browser's own encoder for exact video cuts. The only download is FFmpeg itself, from WeaveAI's own engine server; your file never leaves your device.
- How long does trimming take?
- A normal trim copies the chosen part without re-encoding, so even an hour-long file takes seconds. An exact video cut is re-encoded, at about real time or faster. Files above about 500 MB can run out of browser memory.
- Why does my video start slightly earlier than I asked?
- Without re-encoding, a video can only start on a keyframe, a full picture stored every second or two. The trim starts on the nearest one before your start time. Turn on exact cut to start precisely where you asked.
- Does trimming lower the quality?
- Not by default: the chosen part is copied as it is, bit for bit. Only the exact cut re-encodes the video, at high quality.