htmlhint

HTMLHint is a static code analysis tool for HTML that helps developers write better HTML code by detecting errors, enforcing best practices, and ensuring compliance with HTML standards. It provides fast, configurable HTML validation with comprehensive rule coverage.

Key Features:

Comprehensive rule set covering common HTML issues and best practices
Unclosed tag detection preventing malformed HTML structure
Invalid attribute validation ensuring proper HTML5 compliance
Accessibility checking helping meet WCAG and accessibility standards
Performance optimization detecting performance-impacting HTML patterns
Configurable rules via .htmlhintrc for project-specific requirements
Fast processing optimized for large HTML files and projects
Multiple output formats including JSON and XML for tool integration
Inline rule configuration for granular control over validation
Template support working with various HTML template engines

htmlhint documentation

Version in MegaLinter: 1.6.3
Visit Official Web Site
See How to configure htmlhint rules
- If custom .htmlhintrc config file isn't found, .htmlhintrc will be used
See How to disable htmlhint rules in files
See Index of problems detected by htmlhint

Configuration in MegaLinter

Enable htmlhint by adding HTML_HTMLHINT in ENABLE_LINTERS variable
Disable htmlhint by adding HTML_HTMLHINT in DISABLE_LINTERS variable

Variable	Description	Default value
HTML_HTMLHINT_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
HTML_HTMLHINT_COMMAND_REMOVE_ARGUMENTS	User custom arguments to remove from command line before calling the linter Ex: `-s --foo "bar"`
HTML_HTMLHINT_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\\|lib)`	Include every file
HTML_HTMLHINT_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\\|examples)`	Exclude no file
HTML_HTMLHINT_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`list_of_files`
HTML_HTMLHINT_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".html", ".htm"]`
HTML_HTMLHINT_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
HTML_HTMLHINT_PRE_COMMANDS	List of bash commands to run before the linter	None
HTML_HTMLHINT_POST_COMMANDS	List of bash commands to run after the linter	None
HTML_HTMLHINT_UNSECURED_ENV_VARIABLES	List of env variables explicitly not filtered before calling HTML_HTMLHINT and its pre/post commands	None
HTML_HTMLHINT_CONFIG_FILE	htmlhint configuration file nameUse `LINTER_DEFAULT` to let the linter find it	`.htmlhintrc`
HTML_HTMLHINT_RULES_PATH	Path where to find linter configuration file	Workspace folder, then MegaLinter default rules
HTML_HTMLHINT_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
HTML_HTMLHINT_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`
HTML_HTMLHINT_CLI_EXECUTABLE	Override CLI executable	`['htmlhint']`

IDE Integration

Use htmlhint in your favorite IDE to catch errors before MegaLinter !

IDE	Extension Name	Install
Brackets	brackets-htmlhint	Visit Web Site
Sublime Text	SublimeLinter-contrib-htmlhint	Visit Web Site
Visual Studio Code	vscode-htmlhint

MegaLinter Flavors

This linter is available in the following flavors

Flavor	Description	Embedded linters
all	Default MegaLinter Flavor	127
c_cpp	Optimized for pure C/C++ projects	57
cupcake	MegaLinter for the most commonly used languages	88
documentation	MegaLinter for documentation projects	50
dotnet	Optimized for C, C++, C# or VB based projects	65
dotnetweb	Optimized for C, C++, C# or VB based projects with JS/TS	74
go	Optimized for GO based projects	52
java	Optimized for JAVA based projects	55
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	60
php	Optimized for PHP based projects	55
python	Optimized for PYTHON based projects	66
ruby	Optimized for RUBY based projects	51
rust	Optimized for RUST based projects	51
salesforce	Optimized for Salesforce based projects	55
swift	Optimized for SWIFT based projects	51
terraform	Optimized for TERRAFORM based projects	55

Behind the scenes

How are identified applicable files

File extensions: .html, .htm

How the linting is performed

htmlhint is called once with the list of files as arguments (list_of_files CLI lint mode)

Example calls

htmlhint myfile.html

htmlhint --config .htmlhintrc myfile.html

Help content

Usage: htmlhint <file|folder|pattern|stdin|url ...> [options]

Options:
  -V, --version                                                          output the version number
  -l, --list                                                             show all of the rules available
  --init                                                                 create a new .htmlhintrc config file with default rules
  -c, --config <file>                                                    custom configuration file
  -r, --rules <ruleid, ruleid=value ...>                                 set all of the rules available
  -R, --rulesdir <file|folder>                                           load custom rules from file or folder
  -f, --format <checkstyle|compact|html|json|junit|markdown|sarif|unix>  output messages as custom format
  -i, --ignore <pattern, pattern ...>                                    add pattern to exclude matches
  --nocolor                                                              disable color
  --warn                                                                 Warn only, exit with 0
  -h, --help                                                             display help for command
  Examples:

    htmlhint
    htmlhint www
    htmlhint www/test.html
    htmlhint www/**/*.xhtml
    htmlhint www/**/*.{htm,html}
    htmlhint https://www.example.com/
    cat test.html | htmlhint stdin
    htmlhint --list
    htmlhint --init
    htmlhint --rules tag-pair,id-class-value=underline test.html
    htmlhint --config .htmlhintrc test.html
    htmlhint --ignore **/build/**,**/test/**
    htmlhint --rulesdir ./rules/

Installation on mega-linter Docker image

Dockerfile commands :

# renovate: datasource=npm depName=htmlhint
ARG NPM_HTMLHINT_VERSION=1.6.3

NPM packages (node.js):
- htmlhint@1.6.3