What hidden text is? – Definition
Hidden text is text hidden by formatting tags or other techniques. It is in the source code of the page and can be read by crawlers, but is not visible to users. This technique (also referred to as cloaking) has often been used to suppress keywords and links. Google treats it as a Black Hat SEO practice.
Ways of hiding text that violate Google guidelines:
- Changing the colour of the font to a similar colour to the background of the page (usually white).
- Adding text behind images or other media files.
- Placing text outside your screen using the z-index, position: absolute; or margin properties.
- Use CSS (Cascading Style Sheets) to hide the visibility of text.
- Modify the text font size to zero.
- Hiding text in a server-side scripting language (such as PHP, ASP/.net, JSP, Perl, Node.JS, etc).
- Setting the transparency level to 100%.