HTML button to NOT submit form

By default, html buttons submit a form.

This is due to the fact that even buttons located outside of a form act as submitters (see the W3Schools website: http://www.w3schools.com/tags/att_button_form.asp)

In other words, the button type is "submit" by default

<button type="submit">Button Text</button>

Therefore an easy way to get around this is to use the button type.

<button type="button">Button Text</button>

Other options include returning false at the end of the onclick or any other handler for when the button is clicked, or to using an < input> tag instead

To find out more, check out the Mozilla Developer Network's information on buttons: https://developer.mozilla.org/en/docs/Web/HTML/Element/button

I think this is the most annoying little peculiarity of HTML... That button needs to be of type "button" in order to not submit.

<button type="button">My Button</button>

Update 5-Feb-2019: As per the HTML Living Standard (and also HTML 5 specification):

The missing value default and invalid value default are the Submit Button state.

Dave Markle is correct. From W3School's website:

Always specify the type attribute for the button. The default type for Internet Explorer is "button", while in other browsers (and in the W3C specification) it is "submit".

In other words, the browser you're using is following W3C's specification.

return false; at the end of the onclick handler will do the job. However, it's be better to simply add type="button" to the <button> - that way it behaves properly even without any JavaScript.