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.
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 Standard # interface-formdata |
Browser compatibility
BCD tables only load in the browser