Page Analysis

Browser emulation configuration

User-Agent string: LoadImpactPageAnalyzer/1.5.0 (Load Impact;
Max total connections: 30
Max persistent connections per host: 6
Default keep-alive timeout: 300 s
Accept-Charset: ISO-8859-1;q=0.7, utf-8;q=0.7, *;q=0.7
Accept-Encoding: bzip2, deflate, gzip
Accept-Language: en-us;q=0.8, en;q=0.7, *;q=0.5
Downloads feeds: No
Downloading stylesheet blocks parallel download of other resources: No
Downloading scripts in parallel: Yes
Downloading a stylesheet followed by inline javascript blocks parallel downloads: No
Downloading script blocks parallel download of other resources: No

HTTP Authentication

Client bandwidth limit

Settings Advanced settings
Load time URL Size Status
450 ms

How it works

The page analyzer analyzes your web page performance by emulating how a web browser would load your page and all resources referenced in it. The page and the referenced resources are loaded and important performance metrics are measured and displayed in a waterfall diagram along with other per-resource attributes such as URL, size, compression ratio and HTTP status code. Each load time bar has parts of different color corresponding to a performance metric:
Regular response:
Redirect response:
  • Time in queue: the time a resource is idle in the browser queue waiting to be downloaded.
  • DNS lookup time: the time it takes to resolve the host name into an IP-address.
  • Connect time: the time it takes to establish a connection with the server.
  • Redirect time: the time lost due to a redirect, a response with a HTTP status code of 301, 302, 303 or 307.
  • Time to first byte: the time it took to receive the first byte from the server.
  • Download time: the time spent downloading the resource.
Note: Javascript code is not executed. Resources loaded using Javascript might not be be discovered, loaded and measured.

Emulating web browsers

The page analyzer is capable of emulating a number of well-known web browsers:
  • Chrome 1, 2, 3 and 4
  • Firefox 2, 3 and 3.5
  • Internet Explorer 6, 7 and 8
  • Opera 9.64
  • Safari 3 and 4
The following well-known indexing bots can also be used:
  • GoogleBot 2.1
  • MSNBot 1.1
  • Yahoo! Slurp
The following parameters are emulated:
  • Max allowed connections
  • Max allowed persistent-connections per host
  • If scripts are allowed to be downloaded in parallel (*)
  • If external stylesheets block parallel downloads of other resources (*)
  • If an external stylesheet followed by an inline script blocks parallel downloads (*)
  • If external scripts block parallel downloads of other resources (*)
  • Conditional comments (**)
  • CSS 2.1/3 cascading.
  • User-Agent header string set to the user-agent emulated
  • Accept-Charset header string
  • Accept-Encoding header string to handle compressed resources (gzip, deflate and bzip2)
  • Accept-Language header string to emulate user language preference
(*) - See for more information on web-browser behaviour.
(**) - See for more information.