When this is useful
Removing bars is not automatically an improvement. Cropping can cut off the action; stretching changes the interface geometry. A designed background with an intentionally framed product window may be the clearer treatment.
Diagnose and fix the cause
- Inspect the file itself, outside the website player. If the bars are baked into the pixels, changing the player CSS will not remove them from the downloaded video.
- Compare source and output aspect ratios. Choose contain to preserve the entire frame, or a deliberate crop when the excluded area contains no essential controls.
- For a new mobile demo, record the actual responsive layout. Use a separate landscape version for desktop rather than forcing one source to describe both experiences.
What this looks like in practice
An illustrative 16:9 recording placed inside a square frame leaves unused vertical space when fully contained. That space can hold a short benefit headline and caption. Filling the square by cropping may instead remove the application navigation on either side.
Limits and checks
Do not stretch a recording to fill a target rectangle. A player may also show temporary empty space before metadata loads; give the element a stable aspect ratio and inspect the loaded state.
Your next step
Use the aspect-ratio calculator to compare dimensions, then approve a representative crop before exporting the entire timeline.
References and scope
Examples are illustrative production guidance, not measured customer results. General workflows are not promises of product compatibility. Read our editorial approach and current Demovela scope.