capshak does its heavy media work inside your browser: decoding the video, drawing the waveform, the live preview, effects and the final MP4 encoding. Your video is not uploaded to be edited or exported. This keeps exports fast and private, but it means your browser and device matter.
Supported browsers
- Best: a recent Chrome or Edge on a desktop or laptop.
- Edit and export: recent Chrome, Edge or Safari, on desktop and on iPhone or iPad with iOS 17 or later.
- Edit only: Firefox can open and edit projects, but it may not be able to export.
All of these rely on WebCodecs, the browser feature that lets a web page decode and encode video with the device’s own hardware. Exporting also needs the browser to encode H.264 video, which is why some browsers can edit but not export. The Export video dialog checks this for you and tells you if your browser cannot export. If you see “This browser cannot read this video” or “This browser cannot encode video”, update your browser or switch to Chrome, Edge or Safari. Your project saves automatically, so you can open it in the other browser and export; choose the video file again if it asks.
Video files
- MP4, MOV and WebM work, up to 10 minutes.
- MP4 with H.264 video is the safest choice. If a file will not open, export it as H.264 MP4 from your camera app or another tool and try again.
Tips for slower devices
- Close other heavy tabs and apps while you edit and export.
- Keep the capshak tab open and in front during an export.
- Export at 720p or 1080p instead of Original or 4K, and pick Standard quality for drafts.
- Use 30 fps or 24 fps instead of a high source frame rate.
- Plug in your laptop: many devices slow down video work on battery.
The preview may drop frames on a slow device, but the export renders every frame, so the final video stays smooth.
Editing on a phone
The editor works on phones, with a layout made for touch:
- The viewer sits on top, with a compact timeline and a scrolling tool bar below.
- A tool opens as a panel in place of the timeline. Swipe its handle down or tap ✓ to close it.
- On the timeline, one finger scrolls, a tap selects, and only a selected block can be dragged or trimmed.
- Pinch with two fingers to zoom the timeline. Drag on the ruler to scrub.
- Long-press an item for more actions.
- Turn the phone sideways to put the viewer beside the timeline.
For long or complex edits, a computer is still more comfortable. Your project saves automatically, so you can start on one device and continue on another. See Backup and devices.
Ready to export? See Export your video.