How to prevent ENTER keypress to submit a web form?

[revision 2012, no inline handler, preserve textarea enter handling]

function checkEnter(e){
 e = e || event;
 var txtArea = /textarea/i.test((e.target || e.srcElement).tagName);
 return txtArea || (e.keyCode || e.which || e.charCode || 0) !== 13;
}

Now you can define a keypress handler on the form:
<form [...] onkeypress="return checkEnter(event)">

document.querySelector('form').onkeypress = checkEnter;

Here is a jQuery handler that can be used to stop enter submits, and also stop backspace key -> back. The (keyCode: selectorString) pairs in the "keyStop" object are used to match nodes that shouldn't fire their default action.

Remember that the web should be an accessible place, and this is breaking keyboard users' expectations. That said, in my case the web application I am working on doesn't like the back button anyway, so disabling its key shortcut is OK. The "should enter -> submit" discussion is important, but not related to the actual question asked.

Here is the code, up to you to think about accessibility and why you would actually want to do this!

$(function(){
 var keyStop = {
   8: ":not(input:text, textarea, input:file, input:password)", // stop backspace = back
   13: "input:text, input:password", // stop enter = submit 

   end: null
 };
 $(document).bind("keydown", function(event){
  var selector = keyStop[event.which];

  if(selector !== undefined && $(event.target).is(selector)) {
      event.preventDefault(); //stop event
  }
  return true;
 });
});

Simply return false from the onsubmit handler

<form onsubmit="return false;">

or if you want a handler in the middle

<script>
var submitHandler = function() {
  // do stuff
  return false;
}
</script>
<form onsubmit="return submitHandler()">

You will have to call this function whic will just cancel the default submit behaviour of the form. You can attach it to any input field or event.

function doNothing() {  
var keyCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode;
    if( keyCode == 13 ) {


    if(!e) var e = window.event;

    e.cancelBubble = true;
    e.returnValue = false;

    if (e.stopPropagation) {
        e.stopPropagation();
        e.preventDefault();
    }
}

The ENTER key merely activates the form's default submit button, which will be the first

<input type="submit" />

the browser finds within the form.

Therefore don't have a submit button, but something like

<input type="button" value="Submit" onclick="submitform()" /> 

EDIT: In response to discussion in comments:

This doesn't work if you have only one text field - but it may be that is the desired behaviour in that case.

The other issue is that this relies on Javascript to submit the form. This may be a problem from an accessibility point of view. This can be solved by writing the <input type='button'/> with javascript, and then put an <input type='submit' /> within a <noscript> tag. The drawback of this approach is that for javascript-disabled browsers you will then have form submissions on ENTER. It is up to the OP to decide what is the desired behaviour in this case.

I know of no way of doing this without invoking javascript at all.

stopSubmitOnEnter (e) {
  var eve = e || window.event;
  var keycode = eve.keyCode || eve.which || eve.charCode;

  if (keycode == 13) {
    eve.cancelBubble = true;
    eve.returnValue = false;

    if (eve.stopPropagation) {   
      eve.stopPropagation();
      eve.preventDefault();
    }

    return false;
  }
}

Then on your form:

<form id="foo" onkeypress="stopSubmitOnEnter(e);">

Though, it would be better if you didn't use obtrusive JavaScript.

You can trap the keydown on a form in javascript and prevent the even bubbling, I think. ENTER on a webpage basically just submits the form that the currently selected control is placed in.

I Have come across this myself because I have multiple submit buttons with different 'name' values, so that when submitted they do different things on the same php file. The enter / return button breaks this as those values aren't submitted. So I was thinking, does the enter / return button activate the first submit button in the form? That way you could have a 'vanilla' submit button that is either hidden or has a 'name' value that returns the executing php file back to the page with the form in it. Or else a default (hidden) 'name' value that the keypress activates, and the submit buttons overwrite with their own 'name' values. Just a thought.

How about:

<script>
function isok(e) {
  var name = e.explicitOriginalTarget.name;
  if (name == "button") {
    return true
  }
  return false;
}
</script>
<form onsubmit="return isok(event);">
<input type="text" name="serial"/>
<input type="submit" name="button" value="Create Thing"/>
</form>

And just name your button right and it will still submit, but text fields i.e. the explicitOriginalTarget when you hit return in one, will not have the right name.

If none of those answers are working for you, try this. Add a submit button before the one that actually submits the form and just do nothing with the event.

HTML

<!-- The following button is meant to do nothing. This button will catch the "enter" key press and stop it's propagation. -->
<button type="submit" id="EnterKeyIntercepter" style="cursor: auto; outline: transparent;"></button>

JavaScript

$('#EnterKeyIntercepter').click((event) => {
    event.preventDefault(); //The buck stops here.
    /*If you don't know what this if statement does, just delete it.*/
    if (process.env.NODE_ENV !== 'production') {
        console.log("The enter key was pressed and captured by the mighty Enter Key Inceptor (⌐■_■)");
    }
});

Here's how I'd do it:

window.addEventListener('keydown', function(event)
{
    if (event.key === "Enter" && event.target.tagName !== 'TEXTAREA')
    {
        if(event.target.type !== 'submit')
        {
            event.preventDefault();
            return false;
        }
    }
});