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Smartly add borders and resize video aspect ratios for any platform without cropping the original content.
Choose filesDrop or click to upload your video
Supports MP4/MOV/AVI/MKV/WebM/FLV/WMV
Max 20 MB • Max 1 files
When you need to adapt your video to fit the aspect ratio requirements of different platforms like TikTok (9:16) or Bilibili (16:9), direct cropping will cause the loss of key content. This tool smartly adjusts the aspect ratio by adding customizable borders (defined as the pixel area filled around the original video) and outputs MP4 videos that meet various platform specifications. It supports adjusting border width, color, rounded corners, and background blur effects to achieve professional-level composition optimization.
Q: Why does my vertical video look blurry after adding a border?
A: When the border width exceeds 15% of the original resolution, we recommend enabling the background blur feature (intensity 3-5) to improve visual integration.
Q: Can I batch process multiple videos?
A: Batch processing is not supported at this time; files must be processed one by one. We recommend using professional tools like FFmpeg for large batch processing needs.
• Videos with an alpha channel (e.g., MOV+Alpha) will be converted to opaque MP4s.
• Videos exceeding 4K resolution or 5 minutes in length may trigger a processing timeout.
• On mobile devices, we recommend using the Chrome browser to ensure proper file reading.
For a typical 16:9 to 1:1 conversion scenario: First, set the border width to 40px, choose a light gray gradient (#f5f5f5→#e0e0e0), and enable background blur at intensity 3. This highlights the main subject while avoiding the stiffness of a solid color border. Tested to have <2% quality loss and is compatible with 99% of video players.