Line Numbers?    Language    CSS Upload?      Tab Size           

Language syntax higlighting is a courtesy of the Northern Michigan University Computer Science Department

For more information click here.


  • Select language from the drop down list
  • If text contains tabs, select the size of the tab from the list
  • Paste text into the input box above
  • Click the Highlight button. Highlighted source will appear in this window.

Syntax Checking HTML and CSS

Partial list of checks:
  • Valid HTML tag names are used and are in lower case.
  • HTML Elements properly closed.
  • Attribute name="value" pairs are properly structured.
  • Valid attribute names used. However, the test is not element specific (would allow href in an <h1>).
  • Proper structure (head before body, title included, valid table and list structures, etc.).
  • Classes referenced with the class attribute are defined in the style sheet.
  • Inline style (style attribute) uses correct name:value; syntax and valid CSS property names.
  • Internal/External style sheet syntax is correct including structure of name:value; pairs. Includes checks for valid property names, comment structure, list of tags, braces, etc. CSS property values are not validated in any way (including not checking a value against the specific css property as in using 30px for a color property).
Validation Instructions:

To check an HTML page by itself, select HTML from the Language box, paste the HTML in the top box, and click the Check button. If the HTML page has an internal style sheet, that will be validated with the HTML page with class names in the HTML being verified to exist in the style sheet.

To check a CSS page, select Style Sheet from the Language box and then paste your CSS in the box and click Check button.

If the HTML page has an external style sheet (or sheets), with or without an internal style sheet, select HTML from the Language box and then check the box labeled CSS Upload?. This will open up a second box and label the first box. Paste the HTML in the top box and then the contents of the external style sheet in the second box. If the page references multiple style sheets, paste the style sheets end to end in the second box in the order they occur in the <link> elements.

Changing Colors

To change colors, click the Settings button. You will be presented with a table where you can configure the color, boldness, and style of type (italics or not) for each type of syntax. When you save those changes, a cookie is placed on your computer so that the next time you visit the site, your new colors will be used. You can see the effect of your changes as you save them.

Microsoft Word Export

Once you have pasted your source and selected the language and tab size, you can have the higlighted source exported to a word document by clicking the Word Export button. You will be given the option to save the highlighted source.