What does the parameters mean ?(score_etags, score_keep-alive, score_compress)

WebPageTest Private Instances
1

Hello everyone.

I might be blind but I could not find the documentation that explains each individual property from the results.

Most of them are self explanation, but then there are several that I am a bit unsure about.

Where can I find out more about it?

I just installed a private instance and I am using the “marcelduran/webpagetest-api” for reciving the results from my external test machines.

The results looks like this for example:
“responseCode”: “200”,
“load_ms”: “11”,
“ttfb_ms”: “11”,
“load_start”: “132”,
“bytesOut”: “391”,
“bytesIn”: “3548”,
“objectSize”: “3244”,
“expires”: “Thu, 30 Apr 2015 12:30:20 GMT”,
“cacheControl”: “max-age=2592000”,
“contentType”: “image/png”,
“type”: “3”,
“socket”: “33”,
“score_cache”: “100”,
“score_cdn”: “0”,
“score_gzip”: “-1”,
“score_cookies”: “-1”,
“score_keep-alive”: “100”,
“score_minify”: “-1”,
“score_combine”: “-1”,
“score_compress”: “-1”,
“score_etags”: “-1”,
“is_secure”: “0”,
“dns_ms”: “-1”,
“connect_ms”: “-1”,
“ssl_ms”: “-1”,
“gzip_total”: “0”,
“gzip_save”: “0”,
“minify_total”: “0”,
“minify_save”: “0”,
“image_total”: “0”,
“image_save”: “0”,
“cache_time”: “2592000”,
“dns_start”: “0”,
“dns_end”: “0”,
“connect_start”: “0”,
“connect_end”: “0”,
“ssl_start”: “0”,
“ssl_end”: “0”,

2

The book “Using WebPageTest Web Performance Testing for Novices and Power Users” by Rick Viscomi, Andy Davies, Marcel Duran contains what you’re looking for. I don’t think anywhere else on the net is this information explicitly explained.

3

Unfortunately, the book doesn’t explain every property.

4

Anything with a “score” prefix is one of the optimization checks that are exposed as grades (some have been deprecated or aren’t worth showing in the UI). a -1 means N/A.

For gzip and images, the “save” is how much could be saved by proper compression and “total” is the total bytes it applies to.