The compatibility matrix of the Checkstyle ecosystem has been improved and now offers a highlight feature to help you point out specific columns, rows, or cells.

You may now append a query parameter hl to the compatibility matrix URL to specify the cells to highlight, for example:


The above would highlight the row about Checkstyle 8.4.

A more complex example would be this one:


resulting in multiple rows and columns to be highlighted in differing colors:

Highlight example
Type Syntax Range
Row 8.4 8.4-8.0
Column C C-G
Cell C8.4 C8.4-G8.0
Multi C;8.4 C;8.4-8.0

The type Multi allows a semicolon-separated list of any of the above (row, column, or cell; either single or ranged).

When specifying a range, take care that

  • both elements of the range are of the same type (e.g. C-G is good, 8.4-G is mixed up), and
  • the element that comes first in the table comes first in the range (e.g. C-G or 8.4-8.0 are good, but G-C or 8.0-8.4 are wrong).

The color of each row, column, or cell (range) may be selected by appending the color in square brackets.

Indicator Color Precedence
[R] red 1
[Y] yellow 2 (default)
[B] blue 3
[G] green 4

Yellow is also the default, when no color is given. When areas with different colors overlap, the higher-precendence color is used on the overlap.