You can create both internal and external links using the [[double bracket]] syntax. Internal links go to another tiddler, while external links go to a URL; TiddlyWiki automatically selects the correct type based on the link target. To make the link text different than the target, you place the link text first, followed by a pipe (|) character and then the link target.

Here are some examples:

You can read about links in the [[Links]] section.

You can [[read about links|Links]] if you want to learn more about them.

If you have questions that are not related to TiddlyWiki, let me point you to [[Google|https://google.com]], [[DuckDuckGo|https://duckduckgo.com]], or [[Wikipedia|https://en.wikipedia.org]]. (Or, if you prefer a language other than English, try visiting https://wikipedia.org and selecting a language.)

URLs or paths to files are automatically linked if they appear in the text of your tiddler. However, there are a handful of cases where TiddlyWiki can't automatically detect something as a URL, for instance if it's a relative path to a file on your computer (see Images and Attachments) for why you might want that. Then placing the path by itself will make it normal text, and putting it in double square brackets will try to link to a tiddler with that name. In this case, you can use the ext syntax to force an external link.

attachments/my_image.png

That didn't work. How about [[attachments/my_image.png]]?

Nope! Here's the right way: [ext[attachments/my_image.png]]

If CamelCase links are on in the control panel, words in CamelCase are automatically turned into links. If you want to prevent a CamelCase word from turning into a link, precede it with a tilde: ~CamelCase (note that the tilde will appear literally in the output if you have camel-case linking off, though). See the CamelCase appendix for details.