FormData
Baseline Widely available *
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
* Some parts of this feature may have varying levels of support.
Note: This feature is available in Web Workers.
The FormData interface provides a way to construct a set of key/value pairs representing form fields and their values, which can be sent using the fetch(), XMLHttpRequest.send() or navigator.sendBeacon() methods. It uses the same format a form would use if the encoding type were set to "multipart/form-data".
You can also pass it directly to the URLSearchParams constructor if you want to generate query parameters in the way a <form> would do if it were using simple GET submission.
An object implementing FormData can directly be used in a for...of structure, instead of entries(): for (const p of myFormData) is equivalent to for (const p of myFormData.entries()).
Constructor
FormData()Creates a new
FormDataobject.
Instance methods
FormData.append()Appends a new value onto an existing key inside a
FormDataobject, or adds the key if it does not already exist.FormData.delete()Deletes a key/value pair from a
FormDataobject.FormData.entries()Returns an iterator that iterates through all key/value pairs contained in the
FormData.FormData.get()Returns the first value associated with a given key from within a
FormDataobject.FormData.getAll()Returns an array of all the values associated with a given key from within a
FormData.FormData.has()Returns whether a
FormDataobject contains a certain key.FormData.keys()Returns an iterator iterates through all keys of the key/value pairs contained in the
FormData.FormData.set()Sets a new value for an existing key inside a
FormDataobject, or adds the key/value if it does not already exist.FormData.values()Returns an iterator that iterates through all values contained in the
FormData.
Specifications
| Specification |
|---|
| XMLHttpRequest # interface-formdata |
