What is the default form HTTP method?

Question

It's GET.

Take a look W3C Superceded Recommendation 17.3 The FORM element.

Excerpt:

<!ATTLIST FORM
  %attrs;                              -- %coreattrs, %i18n, %events --
  action      %URI;          #REQUIRED -- server-side form handler --
  method      (GET|POST)     GET       -- HTTP method used to submit the form--
  enctype     %ContentType;  "application/x-www-form-urlencoded"
  accept      %ContentTypes; #IMPLIED  -- list of MIME types for file upload --
  name        CDATA          #IMPLIED  -- name of form for scripting --
  onsubmit    %Script;       #IMPLIED  -- the form was submitted --
  onreset     %Script;       #IMPLIED  -- the form was reset --
  accept-charset %Charsets;  #IMPLIED  -- list of supported charsets --
  >

Good read

Methods GET and POST in HTML forms - what's the difference?

Here is the W3C reference, which says GET is the default.

If not specified, the default is GET. I see no indication that this behaviour has ever been different. And it makes sense the GET is the default, as it specifies that method should be used for actions without side effects.

http://www.faqs.org/faqs/www/cgi-faq/section-37.html

Citations from http://www.w3.org/TR/html401/interact/forms.html#h-17.3:

method = get|post [CI]
This attribute specifies which HTTP method will be used to submit the form data set. Possible (case-insensitive) values are "get" (the default) and "post". See the section on form submission for usage information.

17.13.1 Form submission method
The method attribute of the FORM element specifies the HTTP method used to send the form to the processing agent. This attribute may take two values:

• get: With the HTTP "get" method, the form data set is appended to the URI specified by the action attribute (with a question-mark ("?") as separator) and this new URI is sent to the processing agent.

• post: With the HTTP "post" method, the form data set is included in the body of the form and sent to the processing agent.

The "get" method should be used when the form is idempotent (i.e., causes no side-effects). Many database searches have no visible side-effects and make ideal applications for the "get" method.

According to The W3C standard you're asking for, the default should be GET.