DOMString is a sequence of 16-bit unsigned integers, typically interpreted as UTF-16 code units. This corresponds exactly to the JavaScript primitive String type. When a DOMString is provided to JavaScript, it maps directly to the corresponding String.

When a Web API accepts a DOMString, the value provided will be stringified, using the ToString abstract operation. (For types other than Symbol, this has the same behavior as the String() function.)

Certain Web APIs accepting a DOMString have an additional legacy behavior, where passing null stringifies to the empty string instead of the usual "null".


Specification Status Comment
Web IDLThe definition of 'DOMString' in that specification. Candidate Recommendation
Web IDL Candidate Recommendation This defines how JavaScript values are converted to DOMString and vice versa.

See also