Convert VP9 to MP4 (H.264) via API

VP9 WebM files from YouTube downloads or web recordings need conversion to H.264 MP4 for editing and universal device playback.

Try it in your browser

Loading FFmpeg engine... (~31 MB)

Use the API

curl -X POST https://renderio.dev/v1/commands \
  -H "X-API-KEY: ffsk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
  "ffmpeg_command": "-i {in_video} -c:v libx264 -crf 23 -c:a aac -movflags +faststart {out_video}",
  "input_files": {
    "in_video": "https://example.com/input.webm"
  },
  "output_files": {
    "out_video": "output.mp4"
  }
}'

Need an API key? Get your free API key to start processing files programmatically.

Common Variations

High quality preserve

-i input.webm -c:v libx264 -crf 18 -preset slow -c:a aac -b:a 192k output.mp4

Fast encode

-i input.webm -c:v libx264 -preset fast -crf 25 -c:a aac output.mp4

Scale to 1080p

-i input.webm -vf "scale=1920:-2" -c:v libx264 -crf 23 -c:a aac output.mp4

Related Operations

Convert MP4 to VP9 via API | RenderIO Convert WebM to MP4 via API | RenderIO Convert AV1 to MP4 (H.264) via API | RenderIO Convert MKV to MP4 via API | RenderIO

Need to process at scale?

Automate this with the RenderIO FFmpeg API. Process thousands of files programmatically or through no-code video automation.

Get your API key