How Video Resizer Works
Scale video to 4K, 1080p, 720p, 480p, or a custom resolution — aspect ratio preserved, entirely browser-based.
Try it free →Step-by-step process
- 1
Select target resolution
Choose a preset (4K 3840×2160, 1080p, 720p, 480p, 360p, 240p) or enter custom width and height. Aspect ratio can be maintained automatically or overridden for a specific output shape.
- 2
Scaled canvas encode
The video plays to a canvas sized at the target resolution. The browser scales each frame using bilinear interpolation as the canvas captures and MediaRecorder encodes the output.
- 3
Download at target size
The resized WebM file is offered for download at the specified dimensions. Processing time equals the video duration.
Frequently asked questions
Can I upscale video with the resizer?
Yes — you can set a target resolution larger than the source. For best quality when upscaling, use the Video Upscaler which applies a high-quality Lanczos filter. The basic resizer uses bilinear interpolation which may look soft.
Does resizing preserve aspect ratio?
Yes by default. If you set a custom resolution that does not match the source aspect ratio, you can choose to letterbox, pillarbox, or stretch to fit.
What is the maximum output resolution?
The browser's canvas element has a maximum size of approximately 16384 × 16384 px, but practical limits depend on available GPU memory. 4K (3840 × 2160) is well within limits on modern hardware.