Interaction with HTTP Archives, loosely following the interface of the Archive::HAR Perl module. This Ruby library provides an API to HTTP Archive (.har) files. .har files are JSON-formatted files which contain data about browser interaction with a web page, such as load data, cookie data, load times and URLs of artifacts.

More on HTTP Archives:
HAR Specification


$ gem install http_archive

to use in your script:

require 'http_archive'


http_archive encapsulates all parts of a .har-file as an 'archive' object and fields of that object. To start, you create an HttpArchive::Archive object with a String or File as parameter like so:

archive ='/myfile.har', 'r'))

The 'archive' object now holds data from the archive as attributes, namely the following fields which are objects themselves:

  • A 'browser' object with 'name' and 'version' fields
  • A 'creator' object with 'name' and 'version' fields
  • A 'pages'-array with 'page' objects
  • An 'entries'-array with 'entry' objects

A 'page' object holds data about the page interaction as a whole: When the interaction started, page title, overall load time and so forth. An 'entry' object holds information about every interaction made for that page, such as: duration, request and response data, duration, server information...

To interact with that data, you query the 'archive' object. Examples:

puts # => "Firefox"
puts # => "Firebug"
all_pages = archive.pages # normally just one
puts all_pages.first.on_load # => 6745, 6.7 seconds load time

The 'entry' objects hold data of the requests and responses as objects as well, with the header data as a Hash:

first_entry = archive.entries.first
puts first_entry.request.http_method # => "GET"
puts first_entry.request.headers['Connection'] # => "keep-alive"
# More interesting stuff is here:
puts first_entry.response.content # => {"mimeType"=>"text/html", "size"=>0}
puts first_entry.response.status # => 200
puts page.entry.time # => 54

For more info, see the docs for each class. To summarize the data, http_archive can print out a table representation like the one you are used to from Firebug et cetera:


gives you this:

Metrics for: 'Software is hard', 26 Requests, 0.36MB downloaded. Load time: 6.745s

GET        302 Moved Temporarily    0.0 KB     0.054s
GET /index.php                       301 Moved Permanently    0.0 KB     0.469s
GET   200 OK                   52.95 KB   2.593s
GET /l10n.js?ver=20101110            200 OK                   0.31 KB    0.065s
GET /prototype.js?ver=1.6.1          200 OK                   139.85 KB  1.06s
GET /wp-scriptaculous.js?ver=1.8.3   200 OK                   2.94 KB    0.136s
GET /effects.js?ver=1.8.3            200 OK                   38.47 KB   0.665s
GET /geshi.css                       200 OK                   1.03 KB    0.261s
GET /lightbox.css                    200 OK                   1.42 KB    0.269s
GET /lightbox.js                     200 OK                   23.84 KB   0.55s
GET /rss.gif                         200 OK                   0.62 KB    1.114s
GET /x.png                           200 OK                   1.37 KB    1.151s
GET /useincommandline.png            200 OK                   21.55 KB   2.488s
GET /red-text.png                    200 OK                   18.97 KB   2.778s
GET /simple-log.png                  200 OK                   27.14 KB   3.135s
GET /start-button.png                200 OK                   11.29 KB   2.29s
GET /wordpress.gif                   200 OK                   0.52 KB    2.316s
GET /creativebits.gif                200 OK                   0.34 KB    2.323s
GET /urchin.js                       200 OK                   22.68 KB   1.476s
GET /style.css                       200 OK                   9.24 KB    0.43s
GET /quote.gif                       200 OK                   1.62 KB    1.716s
GET /sidebar_top.gif                 200 OK                   0.11 KB    1.767s
GET /sidebar_bottom.gif              200 OK                   0.11 KB    1.797s
GET /&utmac=UA-3586722-1&utmcc=__u   200 OK                   0.04 KB    1.318s
GET /loading.gif                     200 OK                   2.77 KB    0.071s
GET /closelabel.gif                  200 OK                   0.98 KB    0.089s


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request