# Specification

A long list of regular expressions is used to identify technologies on web pages. Wappalyzer inspects HTML code, as well as JavaScript variables, response headers and more. src/apps.json

Patterns (regular expressions) are kept in src/apps.jon. The following is an example of an application fingerprint.


"Example": {
  "cats": [ 
  "cookies": { 
    "cookie_name": "Example"
  "js": {
    "Example.method": ""
  "excludes": "Example",
  "headers": { 
	"X-Powered-By": "Example" 
  "html": "<link[^>]example\\.css",
  "implies": "PHP\\;confidence:50",
  "meta": { 
	"generator": "(?:Example|Another Example)"
  "script": "example-([0-9.]+)\\.js\\;confidence:50\\;version:\\1",
  "url": ".+\\.example\\.com",
  "website": "https://example.com",

# JSON fields

Find the JSON schema at schema.json.

# Properties (required)

Field Type Description Example
cats Array One or more category IDs. Refer to the list of category IDs. [1, 6]
icon String Application icon filename. "WordPress.svg"
website String URL of the application's website. "https://example.com"

# Implies and excludes (optional)

Field Type Description Example implies String | Array The presence of one application can imply the presence of another, e.g. WordpPress means PHP is also in use. "PHP" excludes String | Array Opposite of implies. The presence of one application can exclude the presence of another. "Apache"

# Patterns (optional)

Field Type Description Example
cookies Object Cookies. { "cookie_name": "Cookie value" }
js Object JavaScript methods (case sensitive). Avoid short patterns to prevent matching minified code. { "jQuery.fn.jquery": "" }
headers Object HTTP response headers. { "X-Powered-By": "^WordPress$" }
html String | Array HTML source code. Patterns must include an HTML opening tag to avoid matching plain text. "<a [^>]*href=\"index.html"
url String Full URL of the page. "^https?//.+\\.wordpress\\.com"
meta Object HTML meta tags, e.g. generator. { "generator": "^WordPress$" }
script String | Array URLs of JavaScript files included on the page. "jquery\\.js"

# Patterns

Patterns are essentially JavaScript regular expressions written as strings, but with some additions.

# Quirks and pitfalls

  • Because of the string format, the escape character itself must be escaped when using special characters such as the dot (\\.). Double quotes must be escaped only once (\"). Slashes do not need to be escaped (/).
  • Flags are not supported. Regular expressions are treated as case-insensitive.
  • Capture groups (()) are used for version detection. In other cases, use non-capturing groups ((?:)).
  • Use start and end of string anchors (^ and $) where possible for optimal performance.
  • Short or generic patterns can cause applications to be identified incorrectly. Try to find unique strings to match.

# Tags

Tags (a non-standard syntax) can be appended to patterns (and implies and excludes, separated by \\;) to store additional information.

Tag Description Example
confidence Indicates a less reliable pattern that may cause false positives. The aim is to achieve a combined confidence of 100%. Defaults to 100% if not specified. "js": { "Mage": "\\;confidence:50" }
version Gets the version number from a pattern match using a special syntax. "script": "jquery-([0-9.]+)\.js\\;version:\\1"

# Version syntax

Application version information can be obtained from a pattern using a capture group. A condition can be evaluated using the ternary operator (?:).

Example Description
\\1 Returns the first match.
\\1?a: Returns a if the first match contains a value, nothing otherwise.
\\1?a:b Returns a if the first match contains a value, b otherwise.
\\1?:b Returns nothing if the first match contains a value, b otherwise.
foo\\1 Returns foo with the first match appended.