Usually form is submitted on Enter when you have focus on input elements.

We can disable Enter key (code 13) on input elements within a form:

$('form input').on('keypress', function(e) {
    return e.which !== 13;
});

DEMO: http://jsfiddle.net/bnx96/325/

Even shorter:

$('myform').submit(function() {
  return false;
});

$('form').keyup(function(e) {
  return e.which !== 13  
});

The event.which property normalizes event.keyCode and event.charCode. It is recommended to watch event.which for keyboard key input.

which docs.

$(document).on('keyup keypress', 'form input[type="text"]', function(e) {
  if(e.which == 13) {
    e.preventDefault();
    return false;
  }
});

This solution works on all forms on website (also on forms inserted with ajax), preventing only Enters in input texts. Place it in a document ready function, and forget this problem for a life.

Most answers above will prevent users from adding new lines in a textarea field. If this is something you want to avoid, you can exclude this particular case by checking which element currently has focus :

var keyCode = e.keyCode || e.which;
if (keyCode === 13 && !$(document.activeElement).is('textarea')) {
  e.preventDefault();
  return false;
}

if you just want to disable submit on enter and submit button too use form's onsubmit event

<form onsubmit="return false;">

You can replace "return false" with call to JS function that will do whatever needed and also submit the form as a last step.

The simple way is to change type of button to button - in html and then add event in js...

Change from this:

<form id="myForm">
   <button type="submit">Submit</button>
</form>

To

<form id="myForm">
   <button type="button" id="btnSubmit">Submit</button>
</form>

And in js or jquery add:

$("#btnSubmit").click(function () {
    $('#myForm').submit();
});

The overkill of having to capture and test every keystroke for the ENTER key really bugs me, so my solution relies on the following browser behavior:

Pressing ENTER will trigger a click event on the submit button (tested in IE11, Chrome 38, FF 31) ** (ref: http://mattsnider.com/how-forms-submit-when-pressing-enter/ )

So my solution is to remove the standard submit button (i.e. <input type="submit">) so that the above behavior fails because there's no submit button to magically click when ENTER is pressed. Instead, I use a jQuery click handler on a regular button to submit the form via jQuery's .submit() method.

<form id="myform" method="post">
  <input name="fav_color" type="text">
  <input name="fav_color_2" type="text">
<button type="button" id="form-button-submit">DO IT!</button>
</form>

<script>
 $('#form-button-submit').click(function(){
    $('#myform').submit();
  });
</script>

Demo: http://codepen.io/anon/pen/fxeyv?editors=101

** this behavior is not applicable if the form has only 1 input field and that field is a 'text' input; in this case the form will be submitted upon ENTER key even if no submit button is present in the HTML markup (e.g. a search field). This has been standard browser behavior since the 90s.

You can do this perfectly in pure Javascript, simple and no library required. Here it is my detailed answer for a similar topic: Disabling enter key for form

In short, here is the code:

<script type="text/javascript">
window.addEventListener('keydown',function(e){if(e.keyIdentifier=='U+000A'||e.keyIdentifier=='Enter'||e.keyCode==13){if(e.target.nodeName=='INPUT'&&e.target.type=='text'){e.preventDefault();return false;}}},true);
</script>

This code is to prevent "Enter" key for input type='text' only. (Because the visitor might need to hit enter across the page) If you want to disable "Enter" for other actions as well, you can add console.log(e); for your your test purposes, and hit F12 in chrome, go to "console" tab and hit "backspace" on the page and look inside it to see what values are returned, then you can target all of those parameters to further enhance the code above to suit your needs for "e.target.nodeName", "e.target.type" and many more...

I don't know if you already resolve this problem, or anyone trying to solve this right now but, here is my solution for this!

$j(':input:not(textarea)').keydown(function(event){
    var kc = event.witch || event.keyCode;
    if(kc == 13){
    event.preventDefault();
        $j(this).closest('form').attr('data-oldaction', function(){
            return $(this).attr('action');
        }).attr('action', 'javascript:;');

        alert('some_text_if_you_want');

        $j(this).closest('form').attr('action', function(){
            return $(this).attr('data-oldaction');
        });
        return false;
    }
});

In firefox, when you at input and press enter, it will submit it's upper form. The solution is in the will submit form add this:

<input type="submit" onclick="return false;" style="display:none" />

$('#FormID').on('keyup keypress', function (e) {
        var keyCode = e.keyCode || e.which;
        if (keyCode === 13) {
            e.preventDefault();
            return false;
        }
    });

The following code will negate the enter key from being used to submit a form, but will still allow you to use the enter key in a textarea. You can edit it further depending on your needs.

<script type="text/javascript">
        function stopRKey(evt) {
          var evt = (evt) ? evt : ((event) ? event : null);
          var node = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
          if ((evt.keyCode == 13) && ((node.type=="text") || (node.type=="radio") || (node.type=="checkbox")) )  {return false;}
        }

        document.onkeypress = stopRKey;
</script> 

3 years later and not a single person has answered this question completely.

The asker wants to cancel the default form submission and call their own Ajax. This is a simple request with a simple solution. There is no need to intercept every character entered into each input.

Assuming the form has a submit button, whether a <button id="save-form"> or an <input id="save-form" type="submit">, do:

$("#save-form").on("click", function () {
    $.ajax({
        ...
    });
    return false;
});

Here is a simple JavaScript solution without using different variations of handling keydown or keypress events:

document.forms[0].addEventListener('submit', function(e) {
    if(document.activeElement.getAttribute('type') !== 'submit') {
        e.preventDefault();
    }
});

Submitting the form will occur only when the active element on your page is the submit button. So you can submit the form by clicking on your submit button or by pressing the ENTER key when the submit button has focus.

I heard which is not recommended, so change Best rated answer to this.

$('#formid').on('keyup keypress', function(e) {
  if (e.key === 'Enter') { 
    e.preventDefault();
    return false;
  }
});

ref. https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/which

Use EnterByTab() for elimnated Enter->Submit form

function EnterByTab(){  //only in form
  $('body').on('keydown', 'input, select, radio', function(e) {
    if (e.key === "Enter") {
      var self = $(this), form = self.parents('form:eq(0)'), focusable, next;
      focusable=form.find(':input,a,select,button,textarea').filter(':visible');
      next = focusable.eq(focusable.index(this)+1);
      var i=1;
      while (next.attr('readonly') || next.prop("type")=="radio") {
        i++;
        next = focusable.eq(focusable.index(this)+i);
      }
      if (next.length) {
        next.focus();
      } else {
        form.submit(); //original behavior
      }
      return false;
    }
  });
}