What is HTTP 3.0? Exploring the key differences between HTTP 2.0 and HTTP 3.0 

HTTP 3.0 is the new standard in development that affects the server and the web browser communication, with notable upgrades for website performance, security, and reliability to provide a better user experience.

http 3.0

Hypertext Transfer Protocol (HTTP) is the backbone of the Internet. The most common versions are HTTP 2.0 and HTTP 3.0.  Here we will discuss the key difference between these two versions.

What is HTTP 3.0?

HTTP 3.0 is the latest version of HTTP (Hypertext Transfer Protocol). It is used to transfer data between a user and a web server over the Internet. It is established on the QUIC (Quick UDP Internet Connections) protocol, which is an experimental transport layer network protocol.

HTTP is the third-generation protocol. In the table below, we have mentioned all HTTP protocol versions along with their release dates & Key features.

HTTP VersionReleasedKey Features
HTTP 0.91991One-line protocol with GET
HTTP 1.01996HTTP header, Status code, POST, and HEAD
HTTP 1.11997More HTTP functionalities, keep-alive connection
HTTP 2.02015Transmission Control Protocol (TCP), header compression (HPACK), a new binary framing layer, multiplexing, server-side push.
HTTP 3.02022QUIC over user datagram protocol (UDP), header compression (QPACK), TLS (Transport Layer Security) by default, connection ID, 

Why is HTTP 3.0 Needed?

HTTP 3.0, the newest iteration of the Hypertext Transfer Protocol (HTTP), is needed to address the challenges and limitations of HTTP 2.0. It will be the first major upgrade to HTTP since it was approved in 2015.

HTTP 3.0 aims to improve the performance, reliability, and security of web communication, especially for scenarios with packet loss or high latency. The biggest advantage is that HTTP 3.0 runs on QUIC (Quick UDP Internet Connections). It is designed for mobile-heavy Internet usage for users who carry mobile devices that constantly switch from one network to another.

See more: Web Caching Startegies

How to Enable HTTP 3.0 on Your Browser?

The latest versions of Mozilla Firefox, Google Chrome, and Safari support HTTP 3.0, but you need to enable HTTP 3.0. 

  • Steps to enable HTTP 3.0 in Google Chrome:

Step 1: Open a new tab in Google Chrome and go to the chrome://flags page.

ouic,http 3.0

Step 2: Search the QUIC flag and enable it. 

http 3.0, quic enable

What is QUIC Protocol?

QUIC (stands for Quick UDP Internet Connections) which is a transport layer network protocol developed by Google. According to the Internet Engineering Task Force (IETF),  QUIC is an encrypted connection-oriented protocol that operates in the Transport Layer or the 4th layer in the OSI (Open System Interconnection) model.

quic protocol

The key benefits of using the QUIC protocol are:

Reduce the Connection Time:

To establish TLS encryption, the server and the client need to perform a TLS handshake and exchange the encryption keys. This process is time-consuming due to the 4 round-trip requests involved. 

http 3.0

Where QUIC is able to replace all these steps with only a single handshake and reduce the connection time.

Better Performance when Data Packets are Lost: 

HTTP 2.0 on TCP can suffer from head-of-line blocking, which indicates that the first packet can hold up a line of data packets. If one data packet is lost, the recipient must wait for the lost packet to be retrieved, which affects the connection performance. 

http 3.0

The QUIC protocol can solve this issue by allowing streams of data to reach their destination independently. So, they no longer need to wait for the missing data packet to be repaired. Even the IP address is changed.

Easier to Improve and Develop:

TCP protocol is implemented in the Kernel operating system, which means you can’t change it easily, whereas QUIC can be implemented in the application layer in the OSI model, making this protocol more flexible

Stable Connection when Networks are Changed:

If the system is connected to the server via Transmission Control Protocol (TCP) and the network connection suddenly changes from 4G to Wi-Fi, the connection needs to be re-established.

This issue can be solved by QUIC. QUIC protocol allows a smoother transition by a unique identifier. These can be created by connection establishment by only sending the packet rather than re-creating the whole connection. 

The Key Difference Between HTTP 2.0 and HTTP 3.0

Now, you have a brief idea of HTTP 2.0 and HTTP 3.0. While both protocols are used for transferring data, they have some key differences. 

http 2.0 vs 3.0

Let’s understand the key difference between HTTP 2.0 and HTTP 3.0.

  • Transport Layer:

HTTP 2.0 operates over TCP (Transmission Control Protocol), which is a standard web communication.

Where HTTP 3.0 uses QUIC (Quick UDP Internet Connection) protocol over UDP. QUIC is a new transport protocol that was developed by Google in 2022

  • Encryption:

While both HTTP 2.0 and HTTP 3.0 support encryption through Transport Layer Security (TLS), the QUIC protocol in HTTP 3.0 can encrypt the entire communication, including the handshake process. 

Encryption

Building the encryption into the protocol itself can improve privacy and security in HTTP 3.0 compared to HTTP 2.0.  

  • Head-of-Line Blocking:

In HTTP 2.0, Head-of-Line blocking issues can be raised where the transmission of a large resource can block the other resource in the same connection, especially for multiple requests.

HTTP 3.0 is designed to solve this issue by allowing independent streams to progress without being delayed by other resources. Reducing the latency improves overall web performance.

See also: Interaction to Next Paint

  • Server Push Efficiency:

Both protocols can support server push, where the server continuously sends the resources to the user without waiting for an HTTP request.

server push

However, HTTP 3.0’s implementation is more efficient due to its underlying transport protocol.

HTTP 3.0 represents the advantage over HTTP 2.0 in terms of overall performance, security, and reliability. The QUIC protocol offers more benefits like better encryption, reduced Head-of-Line blocking issues, and many more.

What is BF Cache? Exploring the Key Benefits of Using BF Cache for a Better User Experience

The bf cache (back / forward cache) is a web browser optimization that is used to enable instant back and forward navigation. It improves the browsing experience, especially for the user who has a slower network or has a slower device.

bf cache

According to Chrome Usage Data, 1 in 10 navigation on desktop and almost 1 in 5 on mobile are either back or forward. Now, how can you ensure that after navigating back and forward to the web page, they load immediately? That is when the bf cache comes into play! 

Here we will cover the concept of bf cache and the key benefits of using this for a better user experience. 

What is bf cache?

A bf cache (also known as back/forward cache) is a feature that allows the browser to create a snapshot of a visited web page and store it in their in-memory. It is used when the user navigates back or forward between the web page.

Let’s understand it with an example, suppose you have performed a Google search to find some information & clicked on a particular search result to find the some information, but you are not happy with the information & press the back button to go back to the search results, now instead of loading the page again the browser would show saved snapshot.

When a user visits a web page, the browser first downloads and parses the resource files of the content such as HTML files and CSS stylesheets. Then render the webpage content. And finally, JavaScript makes the page interactive.

If the back-forward cache is not enabled for a web page, that means every time the user leaves the page and navigates back to it, the browser will go through the whole process. It will decrease the pagespeed performance of the website.  

Check out: Cache vs Cookie

Which browsers support bf cache?

In web technology, bf cache is not a new concept. Safari (a web browser developed by Apple) added this feature in 2009. 

Now, almost all browsers support the back/forward cache. Here we are mentioning some popular browsers.

  • Chrome
  • Firefox
  • Edge.

The difference between an HTTP Cache and a bf Cache?

  • HTTP cache or disk cache is used to store the static resources of the webpage content such as HTM files and CSS files to avoid the redownloading of these static resources. 
  • Whereas the bf cache is more comprehensive. It stores the snapshot of the entire webpage including JavaScript in the in-memory.

In the HTTP cache, not all static resources are allowed to be cached. As a result, every time the user visits the website, the browser needs to re-download the content. With the help of the bf cache, this issue can be avoided. 

How to check if your website can be served from the bf cache?

There are various ways that you can check if your website can be served from the backforward cache or not. Here we would check this in two most popular ways to check the website.

  • Using Chrome DevTools:

Chrome DevTools allows you to check whether the web page is eligible for the bf cache. To check this you need to follow these 5 steps.

Step 1: Visit the page you want to test in Chrome DebTools.

bf cache step 1

Step 2: Right-click on the page and click on Inspect option or you can press F12.

bf cache step 2

Step 3: click on the Application option.

bf cache step 3

Step 4: Select the Back/forward cache in the Background services sections.

bf cache step 4

Step 5: Click on Test back/forward cache

bf cache step 5

Then DevTools allows you to see the status indicating whether the website can use bf cache. 

  • Using Google PageSpeed Insights: 

Another option is to use Google PageSpeed Insights, to check if the website can be served from the back forward cache or not.

bf cache

If the tested web page cannot be restored from the bf cache, the audit will fail. By clicking on the warning, you can see a drop-down menu with the failure reasons.

View more: Immutable Caching

These failure reasons can be categorized into three parts.

 Actionable indicates you can make changes to the website to support the back-forward cache.

Pending Support shows that the web page isn’t eligible for the bf cache for now. But in the future chrome supports it.

Not Actionable indicates you can’t fix this issue on the webpage. 

The Most common issues that prevent bf cache

At this point, you have a brief idea about the bf cache. The main reason that prevents bf caching are:

  • Using Cache-Control: no-store header in your JavaScript code

The Cache-Control HTTP header holds the instructions for both HTTP requests and HTTP responses. No-store header in cache-control will disable all caches. 

cache control
  •  Using Unload event in JavaScript:

The unload event occurs when users navigate away from the web page such as submitting a form, clicking a link, entering a new URL, etc. 

During the unload event JS code can execute the task before the web page unloads such as saving the data. 

5 Strategies to optimize a web page for bf cache 

Here we are mentioning the best strategies that you can apply to fix the issues that prevent back forward cache.

1. Use cache-control: no-store only for the information-sensitive page 

If the webpage contains some sensitive information and caching is not needed then use cache-control: no-store to prevent it from being eligible for the bf caching.

Code for node js server:

app.use((req,res,next) => 

{

res.setheader(‘Cache-Control’, ‘no-cacche’);

next();

});’

For a wordpress website, you can use plugins like Cache-control, Cache control by Cacholong, LH Add Headers, etc. to optimize a web page for bf cache.

On the other hand, if the content of the web page is not static then also cache-control: max-age() is used.

2. Update sensitive data after bf cache restore to optimize a web page for bf cache

A bf cache should not be used on web pages that contain sensitive data. Especially when a user visits the website from a public computer, the next user should not be able to visit that page by just clicking the back button.

componentDidMount() {
console.log('componentDidMount')
window.addEventListener('pageshow', (event) = {
console.log('PAGE_SHOW');
if (event.persisted) {
console.log('PAGE_SHOW_PERSISTED');
}
});
}

 You can achieve this by using event.persisted after a pageshow event.

See more: Cache Policy for static assets

3. Avoid using the unload event to optimize a web page for bf cache

The most common way to optimize the bf cache is to avoid using the unload event. Instead of using the unload event, you can use the pagehide event in the method like addEventListener() to detect when a webpage is visible or hidden to a current user.

window.addEventListener('click', warnAboutLostChanges);

function bindWarnAboutLostChanges() {
  window.addEventListener(
    'beforeunload',
    function(e) {
      if (shouldWarnYouLogic()) {
        e.preventDefault();
        return "You have unsaved changes!";
      }
    }
  );

  window.removeEventListener('click', warnAboutLostChanges);

}

4. Carefully adding beforeunload listeners to optimize a web page for bf cache

The beforeunload event is used to display a warning dialog box to inform users whether they want to leave the current page. Chrome and Safari will allow beforeunload event but Firefox will flag the webpage as ineligible for back forward cache.

5. Use rel=”noopener”  in your script to optimize a web page for bf cache

The rel=”noopener” attribute is used to prevent the current page from being able to access the window.opener property. Instead of using a window.postMessage(), you should use rel=”noopener”.

noopener

Conclusion 

Here, we cover the key benefits of using bf cache and the strategies to fix it. The benefits of a website serving from the bf cache are to reduce data usage, improve core web vitals, and a better user experience.

To optimize your web page for bf cache by applying the mentioned strategies like Using cache-control: no-store only for the information-sensitive page, Updating sensitive data after bf cache restore, Using rel=”noopener”  in your script, Avoiding using the unload event, Using rel=”noopener”  in your script.
Now, it’s your turn to apply these powerful strategies to your website and make your website more user-friendly. It will also increase the website’s conversion rate.