Synchronous vs Asynchronous JavaScript and Why It Matters
best live streaming equipment
Best Live Streaming Equipment for All Budgets (2021 Edition)
April 15, 2021
Everything You Need to Know About Real-Time Bidding
Everything You Need to Know About Real-Time Bidding
April 16, 2021

How Synchronous and Asynchronous JavaScript Compare

synchronous vs asynchronous javascript

In today’s growingly competitive digital landscape, the importance of providing the best possible user experience is pivotal to success. That is particularly true if you’re relying on Google to drive traffic to your website. Google’s upcoming Core Web Vitals update plans to emphasize and reward fast-loading sites even more by boosting their rankings. Luckily, webmasters can improve their sites’ performance by switching from synchronous loading of JavaScript files to asynchronous.

What Is Synchronous Code

Synchronous loading prevents browsers from rendering a page before the execution of a code or script is finished. When a browser runs into a synchronous JavaScript tag, it blocks the rest of the page until the current one is executed. 

That leads to long downtimes where a browser does nothing but wait to finish downloading the JavaScript file. That time could be used much more efficiently — by painting a table or loading a CSS stylesheet, for instance. 

All modern websites have already moved from this loading method because of numerous performance issues and delays in page load times.

JavaScript Is Single-Threaded

JavaScript is traditionally single-threaded. Even with multiple cores, you could only get it to run tasks on a single thread (the main thread).

Luckily, JavaScript gained some tools to help with this problem nowadays. Web workers let you send some of the JavaScript processing off to a separate thread, so you can now run multiple JavaScript chunks simultaneously. Web workers are pretty helpful overall, but they have their limitations — they cannot access DOM, and therefore can’t do any UI updates.

What Is Asynchronous Code

Loading your code asynchronously is significantly superior to doing it synchronously. Asynchronous loading means that the code will be processed simultaneously with the rest of the page’s content. In other words, the browser will have no downtime while loading a page as it will keep working while waiting for the request to be handled and the code executed in the background.

Once the background code finishes running, it calls the callback function to let you know the work is done or that something of interest happened. This approach makes much better use of the CPU power and will speed things up significantly.

Sync vs Async Loading of Brid.TV Player

We at Brid.TV strive to offer our clients the best service possible, so we’re always looking for ways to speed up our player on their web properties. That is why we allow publishers to choose whether they want to implement their player via sync or async embed code. Both of these options are provided in our CMS and WordPress plugin so that publishers can opt for either with a single click of a button.

Synchronous Player Loading

Our synchronous (standard) embed code will load the player’s JavaScript files and their dependencies while putting the loading of the rest of the page and its elements on hold. For example, if four player scripts need to load and each takes 0.3 seconds, the total player’s load time will be 1.2 seconds. This speed may seem pretty impressive, but it leaves much to be desired.

If you want to improve your website’s speed and loading times, you can use our asynchronous embed code, which will work exactly as we’ve explained previously. When rendering the code, the web page will not have to wait for the scripts to load and execute but will instead do it in the background.

As soon as the player’s scripts and their dependencies are loaded, player initialization will start while the rest of the page will continue executing in the background.

Using this approach, Brid.TV scripts load separately from other scripts on the page and minimize the load on the page rendering process.

Although we’re talking about time differences measured in milliseconds, these can have a significant impact as Google and other search engines do recognize this. Having a speedier and more responsive site can improve your SERP rankings.

Asynchronous Player Loading

Opting to load your video player asynchronously will not only improve your site’s speed but will also make much better use of your CPU’s processing power.

When using the asynchronous embed code, if four player scripts need to execute, and each needs 0.3 seconds to load, the total player load time will be only 0.3 seconds! That’s a significant improvement from the previous synchronous scenario where it took 1.2 seconds to finish all loading.

Boost Your Video-Heavy Website’s Loading Speed With Brid.TV’s Asynchronous Player

As you can see, leveraging asynchronous JavaScript loading can boost your site’s speed significantly, and that is likely to have a significant impact on your Google rankings going forward. Websites with lots of video content will be hit particularly hard by the upcoming Google update, as video players are always JavaScript-heavy. That is why getting a lightweight video player will be pivotal to optimizing your site’s performance. 

So if you need to boost your video-heavy site’s speed to prepare for the upcoming Core Web Vitals update, why not give Brid.TV a whirl? Try our player’s asynchronous loading feature and see for yourself just how big of a difference it will make!