How Video Canvas Extender Works
Add letterbox or pillarbox padding to change aspect ratio — 1:1 for Instagram, 9:16 for Stories, 16:9 for YouTube.
Try it free →Step-by-step process
- 1
Select target aspect ratio
Choose a preset (1:1 square, 9:16 portrait, 16:9 landscape, 4:3, 21:9 cinematic) or enter a custom ratio. The tool calculates the canvas size needed to fit your video at the target ratio.
- 2
Padded canvas encode
The video plays centered on a larger canvas filled with your chosen padding colour or blur (background content). A MediaRecorder captures the full canvas including the padding bars and encodes as WebM.
- 3
Download with padding
The padded WebM is offered for download. Your video content is preserved at its original resolution — only the canvas is larger, with padding filling the new space.
Frequently asked questions
What padding options are available?
Solid colour (any hex value), blurred background (a blurred version of the video fills the padding bars — popular for portrait-to-landscape conversions), or transparent (for WebM exports only).
Can I add padding to only one side?
Use the custom ratio option and set an asymmetric target size. The video is centred by default, but you can offset it to push padding to one side.
Will this reduce my video quality?
The video content itself is re-encoded (with some quality loss as with any transcode). The padding areas are synthetic — they are not derived from compressed source content so they do not degrade further.