HTML Output

The gcovr command can also generate a simple HTML output using the --html option:

gcovr --html

This generates a HTML summary of the lines executed. In this example, the file example1.html is generated, which has the following output:

The default behavior of the --html option is to generate HTML for a single webpage that summarizes the coverage for all files. The HTML is printed to standard output, but the -o/--output option is used to specify a file that stores the HTML output.

The --html-details option is used to create a separate web page for each file. Each of these web pages includes the contents of file with annotations that summarize code coverage. Consider the following command:

gcovr --html-details example_html.details.html

This generates the following HTML page for the file example1.cpp:

The --html-nested option is used to create a separate web page for each file and directory. Each of these web pages includes the contents of file with annotations that summarize code coverage. Consider the following command:

Note that the --html and --html-details options need a named output, e.g. via the the -o/--output option. For example, if the output is named coverage.html, then the web pages generated for each file will have names of the form coverage.<filename>.html.

The --html-self-contained option controls whether assets like CSS styles are bundled into the HTML file. The --html report defaults to self-contained mode. but --html-details and --html-nested default to --no-html-self-contained in order to avoid problems with the Content Security Policy of some servers, especially Jenkins.

The --html-theme option controls the theme and color of html report.

--html-theme github.green

--html-theme github.blue

--html-theme github.dark-green

--html-theme github.dark-blue

The --html-template-dir option allows you to use an alternate directory with Jinja2 templates to fully customize the HTML output in detail. If a template is missing from this directory the original is used. It is advised that you start by copying the part you want to modify from the existing default theme templates or the existing github theme templates. Keep in mind the template context data that is passed to these templates MAY change between release versions.

Note that you do not have to copy every single template and can copy and edit only the templates you wish to customize.

Added in version 7.0: Added --html-template-dir

Added in version 6.0: Added --html-nested and --html-syntax-highlighting.

Added in version 5.0: Added --html-self-contained and --no-html-self-contained.

Changed in version 5.0: Default to external CSS file for --html-details.