Why this tool is useful
Reframe short footage for landscape, portrait, square or classic players with an explicit contain-or-crop choice.
Local File Tools · runs locally
Private Video Aspect Ratio Changer
Fit a browser-decodable clip into a standard aspect-ratio canvas and export WebM without uploading the source video.
Ready. Your working data stays in this browser.
Files and capture streams stay on this device. Processing uses browser APIs only; nothing is uploaded to YTSave, the media API or a proxy.
How it works
The browser calculates a bounded target canvas, centers each frame with contain or cover geometry and records local WebM bytes.
Practical example
Place a landscape clip into a 9:16 portrait frame with black bars and verify the resulting ratio before download.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.