10 Tips for Improving Performance of JavaScript Programming

10 Tips for Improving Performance of JavaScript Programming

If you are keen on a career as a developer, you must be well-versed in JavaScript. Yes, it is the most popular programming language on the web. If we go by Statista, then JavaScript is the most used programming language in 2021. 69.7% of developers worldwide use it.

When we think in terms of a beginner’s language that has left an impression on the novice programmer’s mind, then JavaScript is the one that stands out in terms of ease of learning or is built right into the web browser. Moreover, it is a valuable tool for developers to build interactive websites.

It is most often associated with front-end development.

Let us explore further details as to why JavaScript has so much popularity among the development community. First and foremost, that emerges as a decisive winner is that it is simple to learn and easy to implement. Client-side JavaScript runs relatively fast and implements complex features on the web pages.

In this post, we intend to provide insights on some tips for improvement in the performance of JavaScript.

Tips for Improved JavaScript Programming Performance

Here are some of the tips for enhanced performance:

Remove Unused JavaScript

It has a method that reduces the time taken by the browser for code compilation and reduces the transmission time. Suppose you want to get rid of the unwanted JavaScript. In that case, you need to consider particular factors such as detecting functionality that is not used by many users and then eradicating it along with the JavaScript code.

The result is that the website loads faster and provides a better user experience. The developer can also remove a library if that is included by mistake.

Avoid Memory Leakage

It happens to be one of the major skill sets possessed by the JavaScript developer. The reason is the difficulty to gauge the memory required on the device with an app running on the device.

The Java Virtual Machine(JVM) analyzes an application, detects all unused objects, and collects them as Garbage. In the code requesting a new memory reserve for the browser, JavaScript stops due to the Garbage Collector.

Use a Light Code

If the developer wishes to reduce the latency and enhance the speed of the code, then it is recommended that the developers use light and compact code.

When the developer wishes to optimize the application performance, several JavaScript files must be streamlined into one. It enables the developers to fetch as one request instead of that many requests.

Knowhow of Asynchronous Programming

JavaScript comes with an async.js feature to efficiently manage the asynchronous code. The novice developer must understand the challenges of the asynchronous program. The async code is pushed to a queue where it runs after all other codes.

The overall performance of the code may suffer because of the async feature. The idea is to use an asynchronous library that can revert to synchronous blocking calls. The developers must include asynchronous APIs inside their code.

Access Local Variables

JavaScript prioritizes local variables first and then goes for the global ones.

It can access the variables with a local scope at a faster rate. The developer precedes each variable with a let or const for defining the current scope. This way, the developer improves the lookup and speeds up the code.

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Improve Performance by Caching Object

The developer can achieve improved performance with the following two means:

The developers use scripts for access to some objects. They improve the performance by using a variable that has a reference to that object or using a user-defined variable for the repeated access object.

Avoid Unwanted Loops

It is not a good practice for the developer to use a loop because that emphasizes the browser. The loop becomes faster with less work inside the loop. The developers often use efficient programming techniques for optimized code, such as putting the array length within a different variable and avoiding reading the length at each loop iteration.

Save Repetitive DOM items

DOM (Document Object Model) is an application API. It is used to define how a document is accessed and manipulated and how its logical structure looks.

The developer must minimize access to DOM. They can save the element’s value in a local variable when the requirement is to read it several times. They can also decrease the DOM traversal trips. Moreover, one must avoid any memory leak when removing the DOM value by setting the variable value as “null”.

Delay Unnecessary Load of JavaScript

The developer wants the page to load as soon as possible. But, they do not use all the functions in the initial loading of the page. Once the page loads initially, then the functions like clicking, changing tabs may occur.

The initial display of the page is held up with loading and compiling of JavaScript code. When using the RAIL model, the developer is advised by Google to load the blocks after 50 minutes, thereby avoiding interaction with the specified page.

Measure Performance with Tools

The performance of web pages can be best analyzed with a tool called Lighthouse. It allows us to audit SEO, best practices, performance and activities.

Use a tool like PageSpeed from Google for website improvements and performance optimization. The components can identify faults and make automatic adjustments based on the website’s compliance with the best practices for Web Performance.

Moreover, you can collect metrics of the likes of CPU consumption by network simulation with the performance analysis of DevTools. It enables you to fix issues seamlessly. Otherwise, you can use More Tools from Chrome’s main menu for measuring the CPU/memory usage of each tab.

Finally, performance at a granular level is measurable with the Node.js platform. Metrics can measure other performance issues and memory leaks as well.


JavaScript has constantly gained traction as the most used programming language among developers because of the ease of learning and implementation. It is a scripting language for incorporating complex features on web pages.

The programming tips mentioned above enable the developers to render best-in-class applications. Moreover, there are several benefits of using JavaScript as a programming language for the increased speed of the application developed by you.

If you face any performance issues, connect with Cliffex, a mobile app and web development company, which can deliver top-notch JavaScript mobile or web applications.