Browser FFmpeg recipe

Convert Video to MP4 Online with FFmpeg

Create a web-friendly MP4 with H.264 video and AAC audio.

Command

Run this FFmpeg command

ffmpeg -i input.mov -c:v libx264 -crf 23 -preset fast -c:a aac -b:a 128k -movflags +faststart output.mp4

When to use it

  • web playback
  • email sharing
  • platform compatibility

How it works

  1. Upload the video file.
  2. Use the H.264 and AAC compatibility preset.
  3. Run FFmpeg and download the MP4.

Option reference

OptionWhat it does
-c:v libx264Encodes the video as H.264.
-c:a aacEncodes audio as AAC.
-movflags +faststartOptimizes the MP4 for web playback.

Practical notes

  • Use this when copy mode fails or a platform rejects your original file.
  • For smaller files, raise CRF to 26 or 28.

FAQ

Why convert to MP4?

MP4 with H.264 and AAC is widely supported by browsers, phones, and upload platforms.

Can I keep original quality?

Use a lower CRF value such as 18 or 20, but the file will be larger.