Questions, answered
Does trimming re-encode and lose quality?
The trimmed range is written into a new file, so it is re-encoded rather than copied byte-for-byte. At the default quality the difference is not visible in normal viewing. Your original file is untouched on disk either way.
Can I trim out a section from the middle?
Not with this tool — it keeps one continuous range. To delete something in the middle and close the gap, use the remove-sections tool, which is built for exactly that and keeps audio in sync across each join.
How accurate are the cut points?
Cuts land on the frame you select in the preview. On variable frame rate recordings from phones and screen recorders, the nearest available frame is used, which can differ from your requested time by a few milliseconds.
Will the audio stay in sync after trimming?
Yes. The audio is trimmed to the same range as the picture and both are written together, so lip sync is preserved from the first frame of the new clip.
Is there a length limit on the source video?
There is no imposed limit, but the whole job runs on your device, so very long or very high resolution files are bounded by available memory. If a long recording struggles, trim it in two passes or work at a lower resolution.