Check the source and available space
Confirm that webcool can read the source directory and write to the output location. Leave enough space for the new file and temporary processing. Transcoding time depends on duration, resolution, codec, and server performance, so validate settings on a short section first.
Non-destructive output: the editor creates a new MP4 and does not overwrite the source. Keep an independent backup of irreplaceable footage anyway.
Edit the server-side video
Open and preview the video
Start the editor from the file list and confirm picture, sound, duration, and any existing subtitle track.
Set the in and out points
Select the range to keep. Fast trimming may align to nearby keyframes; use compatible transcoding when frame-level precision matters.
Adjust speed and framing
Choose 0.5×, 0.75×, 1×, 1.25×, 1.5×, 2×, or 4× speed. Rotate, flip, crop to 16:9, 9:16, or 1:1, and select original, 1080p, 720p, or 480p output.
Manage audio and subtitles
Set volume from 0–200%, mute, remove, replace, or offset audio. Keep, remove, or replace subtitles and check synchronization in preview.
Export and review
Monitor progress, then inspect the beginning, edit points, ending, audio sync, and subtitles before archiving or sharing.
Choose remuxing or transcoding
| Mode | Best for | Trade-off |
|---|---|---|
| Fast remux | Simple trimming or adding a compatible subtitle | No re-encoding, but cuts may align to keyframes and visual, speed, or audio effects cannot be combined |
| Compatible transcode | Precise cuts, rotation, crop, speed, audio, or broad playback compatibility | Applies all settings but uses more time and compute |
Make remote editing efficient
- Separate source footage, work-in-progress files, and finished exports.
- Test a short range before processing a multi-hour video.
- Schedule heavy jobs away from backups and photo synchronization.
- Include a date or version in exported filenames.
- Keep enough free space to cancel and retry safely.
Frequently asked questions
Does editing modify the original video?
No. webcool writes the result to a new MP4.
Why is export much slower than preview?
Preview mainly decodes the file for playback. Crop, rotation, speed changes, and other edits require the server to re-encode the selected range.
Must the browser download the complete video?
No. The server performs the processing; the browser is used for preview, settings, and progress.