how to find %gzip, %compress img, %cache static

WebPageTest General Discussion
1

Hi,

I was looking into the “Performance Review” Results tab. It has a table where it shows the % of Gzip, Compress Img, Cache static. How are we calculating the percentage. If i do a simple calculation of finding percentage, it doesn’t give me the number which shows there. For e.g. %gzip = no.of gzipped components/no. of components applicable.

Please help me to figure how the percentage is calculated.

Regards,
Akshay

2

Hi Pmeenan,

Please help me here. :slight_smile:

Regards,
Akshay

3

Dear Akshay,

It is not that difficult to figure it out for the “gzip compression” & “optimize images” recommendations.

Please check the following examples and you will see the pattern:

  1. Use gzip compression for transferring compressable responses: 42/100
    762.1 KB total in compressible text, target size = 325.1 KB - potential savings = 437.0 KB

325/762 = 42%

  1. Compress Images: 56/100
    821.3 KB total in images, target size = 465.0 KB - potential savings = 356.3 KB

465/821 = 56%

Regarding the percentage of “browser caching” recommendation, it is most likely the following:
number of images/css/Javascript files without correct expiry headers / number of total images/css/Javascript files

I hope it makes sense.

Regards,
Stavros