HTML4 has been a standard web development tool for more than 10 years. It has been approved and ratified as a standard language for browsers by the World Wide Web Consortium (WC3), an organization that specifies and approves standards for web technologies. However, especially after 2007, things have been changing at a rapid pace due to the advent of the smartphones. This has also impacted the way the webpages are designed and developed. Now apart from the standard desktops, web browsers are also accessing the web through myriad phone devices and tablets and their needs and user experience have to be kept in mind.

However, in this context, even though HTML4 is still a W3C standard for browser applications, it doesn’t fully satisfy the needs of the mobile users and the changing trends in the IT industry. Hence, keeping this in mind, HTML5 has been developed to cater to the latest needs of the developers in the IT industry. HTML5 is more advanced as compared to its older counterpart HTML4. Let us explore some basic differences between HTML4 and HTML5 in detail.

Clearer syntax in HTML5- The syntax in HTML5 is clear and simple as compared to HTML4. One example of this can be the DOCTYPE element. In the HTML4 version, the DOCTYPE declaration was lengthy and messed up and used to refer an external source. However, in HTML5, DOCTYPE element has been made extremely simple.

Multimedia elements- HTML5 contains built in support for integrated multimedia files into web page through video and audio tags. This facility is not available in HTML4 since multimedia content was integrated into the web pages via third party plugins like Silverlight and Flash.

Accessing User Geographical location- In the HTML4 version, it is extremely cumbersome to get the geographical location of the users who are accessing a particular website. This task became much more complicated since the proliferation of mobile devices. On the other hand, it is very easy to get user locations in HTML5. The JS GeoLocation of HTML5 can be used to identify the location of the users accessing a particular website.

Client Side storage- In HTML4, in order to store important data of the client, the cache of the browser was used. However, the cache is limited and cannot support relational storage mechanism. However, in HTML5, this issue has been addressed by Web SQL database and application cache that can be accessed by JavaScript interface of HTML5.

Client Server Communication- Since there are no web sockets available in HTML4, the communication between the client and server was done through streaming and long polling methods. However, in HTML5, there is the JS Web Worker API that allows JavaScript and Browser interface to run in separate threads.

JavaScript Threading Mechanism- In HTML4, there was a drawback that JavaScript and the browser interface with which user interacts run in the same thread thus affecting the performance. On the other hand, HTML5 contains JS Web Worker API that allows JavaScript and Browser interface to run in separate threads.

Browser Compatibility- Since HTML has been in service for more than a decade now, it is compatible with almost all the web browsers. However, since HTML5 is still evolving and currently available tags are being modified and also new tags are been added, browser compatibility may become an issue with HTML5 presently.