Browser FFmpeg recipe

Set Video Bitrate Online with FFmpeg

Create an MP4 encoded around a target video bitrate.

Command

Run this FFmpeg command

ffmpeg -i input.mp4 -c:v libx264 -b:v 2500k -maxrate 3000k -bufsize 5000k -c:a aac -b:a 128k bitrate.mp4

When to use it

  • bitrate limits
  • streaming prep
  • predictable file size

How it works

  1. Upload the video.
  2. Set the target bitrate and maxrate values.
  3. Run FFmpeg and download the encoded MP4.

Option reference

OptionWhat it does
-b:v 2500kSets the target video bitrate.
-maxrate 3000kLimits bitrate peaks.
-bufsize 5000kSets rate control buffer size.

Practical notes

  • CRF usually gives better quality-per-size for simple file compression.
  • Bitrate targets are useful when a platform has a strict limit.

FAQ

Should I use bitrate or CRF?

Use bitrate for target limits and CRF for general quality-based compression.

Will this make exact file sizes?

No, but bitrate settings make size more predictable.