WhatWeb : Next Generation Web Scanner

WhatWeb identifies websites. Its goal is to answer the question, “What is that Website?”. WhatWeb recognises web technologies including content management systems (CMS), blogging platforms, statistic/analytics packages, JavaScript libraries, web servers, and embedded devices.

WhatWeb has over 1800 plugins, each to recognise something different. WhatWeb also identifies version numbers, email addresses, account IDs, web framework modules, SQL errors, and more.

WhatWeb can be stealthy and fast, or thorough but slow. WhatWeb supports an aggression level to control the trade off between speed and reliability.

When you visit a website in your browser, the transaction includes many hints of what web technologies are powering that website. Sometimes a single webpage visit contains enough information to identify a website but when it does not, WhatWeb can interrogate the website further.

The default level of aggression, called ‘stealthy’, is the fastest and requires only one HTTP request of a website. This is suitable for scanning public websites. More aggressive modes were developed for use in penetration tests.

Most WhatWeb plugins are thorough and recognise a range of cues from subtle to obvious. For example, most WordPress websites can be identified by the meta HTML tag, e.g. ”, but a minority of WordPress websites remove this identifying tag but this does not thwart WhatWeb.

The WordPress WhatWeb plugin has over 15 tests, which include checking the favicon, default installation files, login pages, and checking for “/wp-content/” within relative links.

Also Read – RIPVT : Virus Total API Maltego Transform Set For Canari


  • Over 1800 plugins
  • Control the trade off between speed/stealth and reliability
  • Performance tuning. Control how many websites to scan concurrently.
  • Multiple log formats: Brief (greppable), Verbose (human readable), XML, JSON, MagicTree, RubyObject, MongoDB, ElasticSearch, SQL.
  • Proxy support including TOR
  • Custom HTTP headers
  • Basic HTTP authentication
  • Control over webpage redirection
  • IP address ranges
  • Fuzzy matching
  • Result certainty awareness
  • Custom plugins defined on the command line
  • IDN (International Domain Name) support

Example Usage

Using WhatWeb to scan reddit.com.

./whatweb reddit.com
http://reddit.com [301 Moved Permanently] Country[UNITED STATES][US], HTTPServer[snooserv], IP[], RedirectLocation[https://www.reddit.com/], UncommonHeaders[retry-after,x-served-by,x-cache-hits,x-timer], Via-Proxy[1.1 varnish]
https://www.reddit.com/ [200 OK] Cookies[edgebucket,eu_cookie_v2,loid,rabt,rseor3,session_tracker,token], Country[UNITED STATES][US], Email[banner@2x.png,snoo-home@2x.png], Frame, HTML5, HTTPServer[snooserv], HttpOnly[token], IP[], Open-Graph-Protocol[website], Script[text/javascript], Strict-Transport-Security[max-age=15552000; includeSubDomains; preload], Title[reddit: the front page of the internet], UncommonHeaders[fastly-restarts,x-served-by,x-cache-hits,x-timer], Via-Proxy[1.1 varnish], X-Frame-Options[SAMEORIGIN]


WhatWeb – Next generation web scanner version 0.5.0.
Developed by Andrew Horton (urbanadventurer) and Brendan Coles (bcoles)
Homepage: https://www.morningstarsecurity.com/research/whatweb

Usage: whatweb [options]

Enter URLs, hostnames, IP adddresses, filenames or
IP ranges in CIDR, x.x.x-x, or x.x.x.x-x.x.x.x
–input-file=FILE, -i Read targets from a file. You can pipe
hostnames or URLs directly with -i /dev/stdin.

–url-prefix Add a prefix to target URLs.
–url-suffix Add a suffix to target URLs.
–url-pattern Insert the targets into a URL. Requires –input-file,
eg. www.example.com/%insert%/robots.txt
The aggression level controls the trade-off between speed/stealth and
–aggression, -a=LEVEL Set the aggression level. Default: 1.
Aggression levels are:
– Stealthy Makes one HTTP request per target. Also follows redirects.
– Aggressive If a level 1 plugin is matched, additional requests will be
– Heavy Makes a lot of HTTP requests per target. Aggressive tests from all plugins are used for all URLs.

–user-agent, -U=AGENT Identify as AGENT instead of WhatWeb/0.5.0.
–header, -H Add an HTTP header. eg “Foo:Bar”. Specifying a default
header will replace it. Specifying an empty value, eg.
“User-Agent:” will remove the header.
–follow-redirect=WHEN Control when to follow redirects. WHEN may be never', http-only’, meta-only',same-site’, or `always’.
Default: always.
–max-redirects=NUM Maximum number of contiguous redirects. Default: 10.

–user, -u= HTTP basic authentication.
–cookie, -c=COOKIES Provide cookies, e.g. ‘name=value; name2=value2’.
–cookiejar=FILE Read cookies from a file.
–proxy Set proxy hostname and port.
Default: 8080.
–proxy-user Set proxy user and password.

–list-plugins, -l List all plugins.
–info-plugins, -I=[SEARCH] List all plugins with detailed information.
Optionally search with keywords in a comma
delimited list.
–search-plugins=STRING Search plugins for a keyword.
–plugins, -p=LIST Select plugins. LIST is a comma delimited set of
selected plugins. Default is all.
Each element can be a directory, file or plugin name and
can optionally have a modifier, eg. + or –
Examples: +/tmp/moo.rb,+/tmp/foo.rb
-p + is a shortcut for -p +plugins-disabled.
–grep, -g=STRING|REGEXP Search for STRING or a Regular Expression. Shows
only the results that match.
Examples: –grep “hello”
–grep “/he[l]*o/”
–custom-plugin=DEFINITION\tDefine a custom plugin named Custom-Plugin,
–custom-plugin=DEFINITION Define a custom plugin named Custom-Plugin,
Examples: “:text=>’powered by abc'”
“:version=>/powered[ ]?by ab[0-9]/”
“:ghdb=>’intitle:abc \”powered by abc\”‘”
–dorks=PLUGIN List Google dorks for the selected plugin.

–verbose, -v Verbose output includes plugin descriptions. Use twice
for debugging.
–colour,–color=WHEN control whether colour is used. WHEN may be never', always’, or `auto’.
–quiet, -q Do not display brief logging to STDOUT.
–no-errors Suppress error messages.
–log-brief=FILE Log brief, one-line output.
–log-verbose=FILE Log verbose output.
–log-errors=FILE Log errors.
–log-xml=FILE Log XML format.
–log-json=FILE Log JSON format.
–log-sql=FILE Log SQL INSERT statements.
–log-sql-create=FILE Create SQL database tables.
–log-json-verbose=FILE Log JSON Verbose format.
–log-magictree=FILE Log MagicTree XML format.
–log-object=FILE Log Ruby object inspection format.
–log-mongo-database Name of the MongoDB database.
–log-mongo-collection Name of the MongoDB collection. Default: whatweb.
–log-mongo-host MongoDB hostname or IP address. Default:
–log-mongo-username MongoDB username. Default: nil.
–log-mongo-password MongoDB password. Default: nil.
–log-elastic-index Name of the index to store results. Default: whatweb
–log-elastic-host Host:port of the elastic http interface. Default:

–max-threads, -t Number of simultaneous threads. Default: 25.
–open-timeout Time in seconds. Default: 15.
–read-timeout Time in seconds. Default: 30.
–wait=SECONDS Wait SECONDS between connections.
This is useful when using a single thread.

–short-help Short usage help.
–help, -h Complete usage help.
–debug Raise errors in plugins.
–version Display version information. (WhatWeb 0.5.0).


Scan example.com.
./whatweb example.com

Scan reddit.com slashdot.org with verbose plugin descriptions.
./whatweb -v reddit.com slashdot.org

An aggressive scan of wired.com detects the exact version of WordPress.
./whatweb -a 3 www.wired.com

Scan the local network quickly and suppress errors.
whatweb –no-errors

Scan the local network for https websites.
whatweb –no-errors –url-prefix https://

Scan for crossdomain policies in the Alexa Top 1000.
./whatweb -i plugin-development/alexa-top-100.txt \
–url-suffix /crossdomain.xml -p crossdomain_xml

Logging & Output

The following types of logging are supported:

  • –log-brief=FILE Brief, one-line, greppable format
  • –log-verbose=FILE Verbose
  • –log-xml=FILE XML format. XSL stylesheet is provided
  • –log-json=FILE JSON format
  • –log-json-verbose=FILE JSON verbose format
  • –log-magictree=FILE MagicTree XML format
  • –log-object=FILE Ruby object inspection format
  • –log-mongo-database Name of the MongoDB database
  • –log-mongo-collection Name of the MongoDB collection. Default: whatweb
  • –log-mongo-host MongoDB hostname or IP address. Default:
  • –log-mongo-username MongoDB username. Default: nil
  • –log-mongo-password MongoDB password. Default: nil
  • –log-elastic-index Name of the index to store results. Default: whatweb
  • –log-elastic-host Host:port of the elastic http interface. Default:
  • –log-errors=FILE Log errors. This is usually printed to the screen in red.

You can output to multiple logs simultaneously by specifying multiple command line logging options. Advanced users who want SQL output should read the source code to see unsupported features.


Matches are made with:

  • Text strings (case sensitive)
  • Regular expressions
  • Google Hack Database queries (limited set of keywords)
  • MD5 hashes
  • URL recognition
  • HTML tag patterns
  • Custom ruby code for passive and aggressive operations

To list the plugins supported:

$ ./whatweb -l

WhatWeb Plugin List

Plugin Name – Description
1024-CMS – 1024 is one of a few CMS’s leading the way with the implementation…
360-Web-Manager – 360-Web-Manager
3COM-NBX – 3COM NBX phone system. The NBX NetSet utility is a web interface i…
3dcart – 3dcart – The 3dcart Shopping Cart Software is a complete ecommerce s…
4D – 4D web application deployment server
4images – 4images is a powerful web-based image gallery management system. Fe…… (truncated)

Search Plugins

To view more detail about a plugin or search plugins for a keyword:

Plugin Selection

All plugins are loaded by default.

Plugins can be selected by directories, files or plugin names as a comma delimited list with the -p or –plugin command line option.

Each list item may have a modifier: + adds to the full set, – removes from the full set and no modifier overrides the defaults.


  • –plugins +plugins-disabled,-foobar
  • –plugins +/tmp/moo.rb
  • –plugins foobar (only select foobar)
  • -p title,md5,+./plugins-disabled/
  • -p ./plugins-disabled,-md5

The –dorks command line option returns google dorks for the selected plugin. For example, –dorks wordpress returns “is proudly powered by WordPress”

The –grep, -g command line option searches the target page for the selected string and returns a match in a plugin called Grep if it is found.


WhatWeb features several levels of aggression. By default the aggression level is set to 1 (stealthy) which sends a single HTTP GET request and also follows redirects.

  • Stealthy Makes one HTTP request per target. Also follows redirects.
  • Unused
  • Aggressive Can make a handful of HTTP requests per target. This triggers aggressive plugins for targets only when those plugins are identified with a level 1 request first.
  • Heavy Makes a lot of HTTP requests per target. Aggressive tests from all plugins are used for all URLs.

Level 3 aggressive plugins will guess more URLs and perform actions that are potentially unsuitable without permission. WhatWeb currently does not support any intrusion/exploit level tests in plugins.

An example of the different results between level 1 and level 3:

A level 1, stealthy scan identifes that smartor.is-root.com/forum/ uses phpBB version 2:

$ ./whatweb smartor.is-root.com/forum/
http://smartor.is-root.com/forum/ [200] PasswordField[password], HTTPServer[Apache/2.2.15], PoweredBy[phpBB], Apache[2.2.15], IP[], phpBB[2], PHP[5.2.13], X-Powered-By[PHP/5.2.13], Cookies[phpbb2mysql_data,phpbb2mysql_sid], Title[Smartors Mods Forums – Reloaded], Country[GERMANY][DE]

A level 3, aggressive scan triggers additional tests in the phpBB plugin which identifies that the website uses phpBB version 2.0.20 or higher:

$ ./whatweb -p plugins/phpbb.rb -a 3 smartor.is-root.com/forum/
http://smartor.is-root.com/forum/ [200] phpBB[2,>2.0.20]

Note the use of the -p argument to select only the phpBB plugin. It is advisable, but not mandatory, to select a specific plugin when attempting to fingerprint software versions in aggressive mode. This approach is far more stealthy as it will limit the number of requests.

WhatWeb has no caching so if you use aggressive plugins on redirecting URLs you may fetch the same files multiple times.

Performance & Stability

WhatWeb features several options to increase performance and stability.

  • –max-threads, -t Number of simultaneous threads. Default: 25.
  • –open-timeout Time in seconds. Default: 15
  • –read-timeout Time in seconds. Default: 30
  • –wait=SECONDS Wait SECONDS between connections This is useful when using a single thread.

The –wait and –max-threads commands can be used to assist in IDS evasion.

Changing the user-agent using the -U or –user-agent command line option will avoid the Snort IDS rule for WhatWeb.

If you are scanning ranges of IP addresses, it is much more efficient to use a port scanner like massscan to discover which have port 80 open before scanning with WhatWeb.

Character set detection, with the Charset plugin dramatically decreases performance by requiring more CPU. This is required by JSON and MongoDB logging.

Optional Dependencies

To enable MongoDB logging install the mongo gem. gem install mongo

To enable character set detection and MongoDB logging install the rchardet gem. gem install rchardet cp plugins-disabled/charset.rb my-plugins/

Writing Plugins

Plugins are easy to write. Start by going through the plugin tutorials in the my-plugins/ folder.

An overview of the plugin tutorials is here. plugin-tutorials.txt

After progressing through the tutorials read through the Development section of the wiki.

Updates & Additional Information

The WhatWeb development build features regular updates.

  • Check the development branches for unreleased updates.

Browse the wiki for more documentation and advanced usage techniques.

Release History

  • Version 0.5.0 Released June 9th, 2019
  • Version 0.4.9 Released November 23rd, 2017
  • Version 0.4.8-dev (Continuous release from 2012 to 2017)
  • Version 0.4.7 Released April 5th, 2011
  • Version 0.4.6 Released March 25th, 2011
  • Version 0.4.5 Released August 17th, 2010
  • Version 0.4.4 Released June 29th, 2010
  • Version 0.4.3 Released May 24th, 2010
  • Version 0.4.2 Released April 30th, 2010
  • Version 0.4.1 Released April 28th, 2010
  • Version 0.4 Released March 14th, 2010
  • Version 0.3 Released at Kiwicon III (kiwicon.org), November 2nd, 2009



  • Andrew Horton (@urbanadventurer)
  • Brendan Coles (@bcoles)