Document colour contrast fix calculator
List the colour pairs in your document (where, text colour, background, size). You get the contrast ratio, the target and the closest colour that passes, as a fix table.
How it works
Contrast errors in an accessibility report are fixed in the source file, not in the PDF. A checker tells you a pair fails; it does not tell you which colour to change it to, or keep a list per page for the designer.
How to use it: one line per colour pair โ where it is, text colour, background colour, size in pt (or px), and bold if it is bold. Choose AA or AAA and press Calculate fixes. Copy the CSV fix table into your source document notes.
The suggested colour keeps the hue and changes only lightness, the smallest change that passes, so brand colours stay recognisable. If no text colour can pass on that background, it tells you to change the background instead.
FAQ
Is anything uploaded?
No. It is calculated in your browser.
Which formula?
WCAG 2.x relative luminance contrast. Large text is 18pt or more, or 14pt bold.
Does this make my PDF accessible?
No โ contrast is one item. Tags, reading order, table headers and alt text are checked separately.