Powered by WebAssembly
Resize Video Online (Free, No Upload)
Resize any video to your target resolution right in your browser. Nothing gets uploaded to a server. Scale up, scale down, or fit to exact pixel dimensions for any platform or project. The processing runs locally using FFmpeg compiled for your browser, so your files stay on your device.
Try it in your browser
Loading FFmpeg engine... (~31 MB)
Use the API
curl -X POST https://renderio.dev/api/v1/run-ffmpeg-command \
-H "X-API-KEY: ffsk_your_api_key" \
-H "Content-Type: application/json" \
-d '{
"ffmpeg_command": "-i {in_video} -vf \"scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1:color=black\" {out_video}",
"input_files": {
"in_video": "https://example.com/input.mp4"
},
"output_files": {
"out_video": "output.mp4"
}
}'Need an API key? Get your free API key to start processing files programmatically.
Common Variations
Scale to 1080p (maintain aspect ratio)
-i input.mp4 -vf scale=-2:1080 output.mp4Scale to 4K
-i input.mp4 -vf scale=3840:2160 -c:v libx264 -crf 18 output.mp4Half resolution
-i input.mp4 -vf scale=iw/2:ih/2 output.mp4Exact dimensions with stretch
-i input.mp4 -vf scale=1920:1080 output.mp4Related Operations
Need to process at scale?
Automate this with the RenderIO FFmpeg API. Process thousands of files programmatically or through no-code video automation.