Video letterbox
Fit a local video inside a selected aspect ratio with padded bars, then record a new WebM in real time. Up to 100 MiB, 5 minutes, 16 megapixels and 4096 px per side. Browser codec support is required. Audio is routed into the recording; timing and quality may change. MP4, original encoding and source metadata are not preserved. No upload; keep this tab visible. Input limit: 100 MiB; output limit: 200 MiB. Pixel and duration limits apply to the input video.
A QUICK WALKTHROUGH
How to use this tool
- Video
- Output aspect ratio
- Record and download WebM
Video preview
Fit a local video inside a selected aspect ratio with padded bars, then record a new WebM in real time. Up to 100 MiB, 5 minutes, 16 megapixels and 4096 px per side. Browser codec support is required. Audio is routed into the recording; timing and quality may change. MP4, original encoding and source metadata are not preserved. No upload; keep this tab visible. Input limit: 100 MiB; output limit: 200 MiB. Pixel and duration limits apply to the input video.
GOOD TO KNOW
Common questions
Record and download WebM
Fit a local video inside a selected aspect ratio with padded bars, then record a new WebM in real time. Up to 100 MiB, 5 minutes, 16 megapixels and 4096 px per side. Browser codec support is required. Audio is routed into the recording; timing and quality may change. MP4, original encoding and source metadata are not preserved. No upload; keep this tab visible. Input limit: 100 MiB; output limit: 200 MiB. Pixel and duration limits apply to the input video.