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AVI to MP4 Converter (Free, Online, No Upload)

Convert any AVI file to MP4 right in your browser. Nothing gets uploaded to a server. AVI is a legacy format that lacks modern streaming support. Converting to MP4 with H.264 encoding gives you smaller file sizes, web playback, and universal compatibility. The conversion runs locally using FFmpeg compiled for your browser.

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} -c:v libx264 -crf 23 -c:a aac -movflags +faststart {out_video}",
  "input_files": {
    "in_video": "https://example.com/input.avi"
  },
  "output_files": {
    "out_video": "output.mp4"
  }
}'

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

Common Variations

Fast encode with lower quality
-i input.avi -c:v libx264 -preset ultrafast -crf 28 -c:a aac output.mp4
Preserve original quality
-i input.avi -c:v libx264 -crf 18 -preset slow -c:a aac -b:a 192k output.mp4
1080p cap with scaling
-i input.avi -vf "scale=1920:-2:flags=lanczos" -c:v libx264 -crf 23 -c:a aac output.mp4

Related Operations

Free MP4 to AVI Converter Online | RenderIOFree MKV to MP4 Converter Online | RenderIOConvert MOV to MP4 Online Free, No Upload | RenderIOCompress Video Online Free, No Upload Required | 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