TiddlyWiki is in persoanlike wiki en in net-lineêr notebook foar it organisearjen en dielen fan komplekse ynformaasje. It is in iepenboarne single pagina-applikaasje Wiki yn 'e foarm fan in ien HTML-bestân dat CSS, JavaScript omfettet, en de ynhâld. It is ûntworpen om maklik te wêzen en opnij oan te passen en opnij te foarmjen, ôfhinklik fan tapassing. It fasiliteart opnij gebrûk fan ynhâld troch it te dielen yn lytse stikken neamd Tiddlers.

TiddlyWiki is designed for customization and to be shaped according to users’ specific needs, perhaps comparable to a high-end programming language. As such, it can be shaped into a wide and arbitrary range of special applications. Examples include niche note taking applications, to-do lists, presentations, collections, authoring tools, personal databases, recipe collections, etc.

Although there are many TiddlyWiki documents on the Web, the majority of TiddlyWikis reside on personal computers or in the cloud, or are exchanged over email, in a manner similar to word processing documents and spreadsheets. As a single HTML file, or saved as an HTA file in Microsoft Windows (allowing corporate IE lockdown to be bypassed), TiddlyWiki can be useful in corporate environments where red tape or IT resources might prevent the use of a wiki that requires a more complicated installation.