<form>

HTML <form> 元素表示提交訊息的區塊,此區塊含有許多可互動的控制項。

It is possible to use the :valid (en-US) and :invalid (en-US) CSS pseudo-classes to style a <form> element based on whether or not the elements (en-US) inside the form are valid.

Content categories Flow content, palpable content
Permitted content Flow content, but not containing <form> elements
Tag omission None, both the starting and ending tag are mandatory.
Permitted parents Any element that accepts flow content
Implicit ARIA role form if the form has an accessible name, otherwise no corresponding role
Permitted ARIA roles search, none or presentation
DOM interface HTMLFormElement

Attributes

This element includes the global attributes.

accept This is an obsolete API and is no longer guaranteed to work.
Comma-separated content types the server accepts.
This attribute was removed in HTML5 and should not be used. Instead, use the accept attribute on <input type=file> elements.
accept-charset
Space-separated character encodings the server accepts. The browser uses them in the order in which they are listed. The default value means the same encoding as the page.
(In previous versions of HTML, character encodings could also be delimited by commas.)
action
The URL that processes the form submission. This value can be overridden by a formaction attribute on a <button>, <input type="submit">, or <input type="image"> element.
autocapitalize
A nonstandard attribute used by iOS Safari that controls how textual form elements should be automatically capitalized. autocapitalize attributes on a form elements override it on <form>. Possible values:
  • none: No automatic capitalization.
  • sentences (default): Capitalize the first letter of each sentence.
  • words: Capitalize the first letter of each word.
  • characters: Capitalize all characters — that is, uppercase.
autocomplete
Indicates whether input elements can by default have their values automatically completed by the browser. autocomplete attributes on form elements override it on <form>. Possible values:
  • off: The browser may not automatically complete entries. (Browsers tend to ignore this for suspected login forms; see The autocomplete attribute and login fields.)
  • on: The browser may automatically complete entries.
enctype
If the value of the method attribute is post, enctype is the MIME type of the form submission. Possible values:
  • application/x-www-form-urlencoded: The default value.
  • multipart/form-data: Use this if the form contains <input> elements with type=file.
  • text/plain: Introduced by HTML5 for debugging purposes.

This value can be overridden by formenctype attributes on <button>, <input type="submit">, or <input type="image"> elements.

method
The HTTP method to submit the form with. Possible values:

This value is overridden by formmethod attributes on <button><input type="submit">, or <input type="image"> elements.

name
The name of the form. Deprecated as of HTML 4 (use id instead). It must be unique among the forms in a document and not an empty string as of HTML5.
novalidate
This Boolean attribute indicates that the form shouldn't be validated when submitted. If this attribute is not set (and therefore the form is validated), it can be overridden by a formnovalidate attribute on a <button><input type="submit">, or <input type="image"> element belonging to the form.
rel
Creates a hyperlink or annotation depending on the value, see the rel attribute for details.
target
Indicates where to display the response after submitting the form. In HTML 4, this is the name/keyword for a frame. In HTML5, it is a name/keyword for a browsing context (for example, tab, window, or iframe). The following keywords have special meanings:
  • _self (default): Load into the same browsing context as the current one.
  • _blank: Load into a new unnamed browsing context.
  • _parent: Load into the parent browsing context of the current one. If no parent, behaves the same as _self.
  • _top: Load into the top-level browsing context (i.e., the browsing context that is an ancestor of the current one and has no parent). If no parent, behaves the same as _self.

This value can be overridden by a formtarget attribute on a <button><input type="submit">, or <input type="image"> element.

Examples

HTML

<!-- Form which will send a GET request to the current URL -->
<form>
  <label>Name:
    <input name="submitted-name" autocomplete="name">
  </label>
  <button>Save</button>
</form>

<!-- Form which will send a POST request to the current URL -->
<form method="post">
  <label>Name:
    <input name="submitted-name" autocomplete="name">
  </label>
  <button>Save</button>
</form>

<!-- Form with fieldset, legend, and label -->
<form method="post">
  <fieldset>
    <legend>Title</legend>
    <label><input type="radio" name="radio"> Select me</label>
  </fieldset>
</form>

Specifications

Specification Status Comment
HTML Living Standard
The definition of '<form>' in that specification.
Living Standard
HTML5
The definition of '<form>' in that specification.
Recommendation
HTML 4.01 Specification
The definition of '<form>' in that specification.
Recommendation Initial definition

Browser compatibility

BCD tables only load in the browser

See also