Convert WebM to MP4 via API

WebM files from screen recordings or web sources often need conversion to MP4 for editing or sharing. Convert with optimal H.264 settings for universal 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 for previews

-i input.webm -c:v libx264 -preset ultrafast -crf 28 -c:a aac output.mp4

Scale to 1080p max

-i input.webm -vf "scale=min(1920\,iw):-2" -c:v libx264 -crf 23 -c:a aac output.mp4

Related Operations

Convert MP4 to WebM via API | RenderIO Convert MKV to MP4 via API | RenderIO Convert AVI to MP4 via API | RenderIO Compress Video 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