responseText

ResponseText is a property of the XMLHttpRequest interface used in web browsers to expose the server’s response data as plain text. When a request completes successfully, responseText contains the response body interpreted as a string. It is commonly used for textual responses such as HTML, plain text, or XML, and is often contrasted with binary-oriented approaches or with higher-level APIs that automatically parse formats like JSON.

Access to responseText occurs after the load event, once the data has been received. If the response body is not textual or if the request is not finished, responseText may be empty or undefined. The text is decoded using the character encoding specified by the server in the Content-Type header; if encoding is unclear or mismatched, the resulting string may appear garbled.

In practice, responseText is frequently used to manually parse responses, for example to extract data from HTML or to handle non-JSON payloads. For JSON data, developers typically call JSON.parse on responseText to convert it to an object. For binary data, or when a more modern approach is preferred, other XHR properties or the Fetch API are used.

Compatibility and evolution: responseText has been part of the traditional XMLHttpRequest API for many years and remains widely encountered in legacy code. Modern web development often favors the Fetch API, where the equivalent operation is achieved via response.text(), which returns a promise resolving to a string. This shift reflects a move toward promise-based, streaming, and more flexible handling of responses.

See also: XMLHttpRequest, response, responseXML, responseType, Fetch API, JSON.parse.