Unlock The Full Potential Of JavaScript: 10 Tips & Tricks For Ultimate Performance
Find how to speed up your web pages by removing bottlenecks in your JavaScript.
JavaScript is important in web development. Most of the activity & motion on web pages are controlled by language.
But, if the code is poorly written, JavaScript might cause a website to slow down.
Shortfalls can lead to slow loading times as well as slow rendering speeds.
Follow the following strategies to boost your website’s speed and performance.
- Locally define variables
- JavaScript should be loaded asynchronously
- Avoid Extraneous Loops
- Minimize JavaScript Code
- Use Gzip to compress large files
- Reduce DOM access
- Delay unnecessary JavaScript loading
- Make use of a CDN to load JavaScript
- Reduce Memory Leaks
- Make Use of Problem-Detection Tools
By following these strategies, you can improve your website’s speed and performance, which can lead to a better user experience and higher search engine rankings.
1. Locally define variables
As a programmer, you must know how scoping works.
Variables in JavaScript are divided into two categories: local variables and global variables.
Variables defined within a function block are known as local variables.
The scope is restricted to the function in which they are defined.
Global variables are variables that can be used throughout the script.
The scope of global variables remains constant throughout the program.
When you try to get to a variable, the browser does a scope query.
It searches the nearest scope for the variable and keeps looking until it finds it.
As a result, the longer it takes to access variables outside of the current scope, the more scope chain you have in your code.
As a result, it’s ideal to define variables closer to the execution context.
Only use global variables in rare situations, such as when storing data used throughout the script.
This minimizes the number of scopes in your code, leading to improved performance.
2. JavaScript should be loaded asynchronously
JavaScript is a programming language with a single thread.
This means that once a function is performed, it must complete before another function can be done.
This structure can lead to situations when code blocks the thread and leads the program to hang.
To keep the thread running smoothly, you should conduct time-consuming activities asynchronously.
When a task runs asynchronously, it does not use the entire processing capacity of the thread.
Instead, the function is added to an event loop and is called after all other codes have been executed.
Since API requests take time to resolve, they are perfect for the asynchronous pattern.
Instead of freezing the thread, you’d use a promise-based library, such as the fetch API, to get the info asynchronously.
Other code can start while the browser gets data from the API in this way.
The complex nature of asynchronous programming can help you boost the speed of your application.
3. Avoid Extraneous Loops
If you’re not careful, using loops in JavaScript can be deadly.
Cycling through a variety of objects can be demanding on the browser.
You can’t avoid using loops in your code, you should use them as rarely as possible.
A few strategies can be used to avoid having to loop through the collection.
For example, rather than reading the length of an array on each loop iteration, you can store it in a different variable.
If you get what you want from a loop, get out of it as quickly as you can.
4. Minimize JavaScript Code
Minification is a powerful technique for optimizing JavaScript code.
A minimizer is a program that converts your raw source code into a smaller production file.
They delete unnecessary comments, shorten lengthy variable names, and cut unnecessary syntax.
They also delete unnecessary code and improve existing routines to use fewer lines of code.
Google Closure Compiler, UglifyJS, and Microsoft AJAX minified are examples of minimizes.
You can also minify your code yourself by reviewing it and searching for methods to improve it.
You can, for example, simplify your code’s if statements.
5. Use Gzip to compress large files
Gzip is frequently used by clients to compress and decompress big JavaScript files.
When a browser requests a resource, the server can compress it to deliver a smaller file in the response.
After the client receives the file, it decodes it.
Overall, this strategy saves data and reduces latency, boosting application performance.
6. Reduce DOM access
Because the browser must refresh with each DOM update, accessing the DOM might affect the performance of your application.
It’s better to keep DOM access to a limit.
One method is to save references to browser objects.
You can also use a package like React to make changes to the virtual DOM before pushing them to the real DOM.
As a result, instead of refreshing the entire page, the browser refreshes the elements of the program that need updating.
7. Delay unnecessary JavaScript loading
While it is important that your website loads quickly, not all functions must be operational on the first load.
Suppose you have a clickable button and a tab menu that both reference JavaScript code; both can be delayed until the page loads.
This strategy frees up computing resources, allowing you to render the required page elements on time.
You put off generating code that might hold up the page’s first display.
When the website has finished loading, you can start loading the features.
As a result, the user can gain from a quick load time and begin engaging with the content.
You can also add a little CSS and JavaScript as possible in your head element to guarantee that it loads quickly.
Secondary code can then be stored in separate.css and.js files.
This strategy needs a solid understanding of how the DOM works.
8. Make use of a CDN to load JavaScript
The use of a content delivery network can help speed up page load time, but it’s not always successful.
For example, if you select a CDN that does not have a local server in the visitor’s country, they will not benefit.
To solve that problem, you can use tools to assess many CDNs and decide which one provides the greatest performance for your use case.
Visit the cdnjs website to find out which CDN is best for your library.
9. Reduce Memory Leaks
Memory leaks can harm the performance of an application.
Leaks come when the loaded page uses more and more memory.
A memory leak happens when your browser begins to slow down after a lengthy session of working with the program.
Memory leaks in your application can be detected using Chrome Developer Tools.
The timeline is recorded by the tool under the performance tab. Following information leaks happen as a result of DOM element removals.
When all variables referencing these items are no longer in scope, the garbage collector will free memory.
10. Make Use of Problem-Detection Tools
Lighthouse, Google PageSpeed Insights, and Chrome can all help you in detecting issues.
Lighthouse looks for issues with accessibility, performance, and SEO.
Google PageSpeed can help you with reducing JavaScript to boost the load time of your website.
The Chrome browser has a Developer Tools feature that you can activate by pressing F12 on your keyword.
You can use its performance analysis to turn on and off the network and check CPU use.
It also checks other statistics to fix areas with your website.
How to Troubleshoot Using Google Developer Tools
As a web developer, you’ll spend a lot of time on your browser.
Most browsers have a set of developer features that can help you in resolving website bugs.
The Developer Tools feature in Google Chrome can help you with a variety of tasks.
