speedline

Calculate the speed index and visual performance metrics from chrome dev tool timeline.

Navigation Timing API provides useful data that can be used to measure the performance of a website.

Unfortunately this API has never been good at capturing the actual user experience that's where speedline comes to rescue.

It measures how fast the page content is visually displayed.

The current implementation is based on the Visual Progress from Video Capture calculation method described on the Speed Index page.

The visual progress is calculated by comparing the distance between the histogram of the current frame and the final frame.

GET IT:

$ npm install --global speedline // For CLI

$ npm install --save speedline // As a devdep.

Sample usage:

1
2
3
4
5
6
7
8
9
10

$ speedline --help

  Usage
    $ speedline <timeline> [options]

  Options
    -p, --pretty  Pretty print the output

  Examples
    $ speedline ./timeline.json

GIF FTW!