HTML5 forms allow creation of highly interactive web pages. Moreover, HTML5 provide for faster and efficient form data processing making it user friendly and code independent. For instance, HTML5 forms allow searching through the page natively. It was not possible in all prior HTML versions and you needed some kind of script running along your HTML to do any kind of searching. 

However, there are limitations when it comes to HTML5 forms. Modern browsers don’t fully support HTML5 forms and limit HTML5 capabilities as a result. Let’s look at some of these limitations. 

As you can see from the table above, HTML5 forms are not supported 100% by any of the existing and modern browsers. As a result, you need to be careful when creating pure HTML5 forms and you should always thank about ways to handle HTML5 form element if its not supported by user's browser.