Skip to content
Alerty-Logo dk

13 Front End Performance Best Practices For Improving Site Performance

You just launched a new website that took weeks to create. You’re excited to share your new site with the world, so you post it on social media and email your contacts. Then, you sit back and watch the traffic roll in, only to find that it loads quickly when you visit your new site. You've just discovered that your website's performance is subpar, and your users are already bouncing off your site instead of enjoying the smooth experience you intended to deliver. Performance issues can be devastating, especially for a new site. Not only do they hurt user experience, but they also impact search rankings. Research shows that Google prioritizes speed when ranking websites. If your site is slow, it will likely be buried on the search engine results pages. 

Front end performance is a critical aspect of website performance monitoring that focuses on the speed of a website's visual elements. The quicker these elements load, the faster users can access the information they seek. Front end monitoring tools help you keep tabs on these visual elements to identify and fix speed issues—before your visitors notice them. In this blog, we'll explore front-end performance, why it matters, and how to improve it with the help of front end monitoring tools.

Alerty-Logo dk

Table of Contents

What Is Front-End Performance?

person concentrating on tasks - Front End Performance

Front-end performance is all about how fast and efficiently the parts of your website that users interact with—like text, images, buttons, and menus—load and function. It’s the difference between a user smoothly navigating your site or getting frustrated with:

  • Slow load times 
  • Jumping ship

When discussing front-end performance, we look at how quickly your website’s visual elements load and become interactive. This includes everything from the main text and images to more complex features like:

  • Animations
  • Videos
  • Forms If these elements take too long to load, users might get impatient, leading to higher bounce rates (people leaving your site before it fully loads).

The Elements of Front End Performance

It’s important to remember that front-end performance isn't just about speed—it’s about ensuring a seamless experience. Smooth scrolling, stable layout, and instant responses to clicks or taps all contribute to great performance. 

Good front-end performance makes your website feel:

  • Fast
  • Intuitive
  • Enjoyable to use

Why Front End Performance Matters

This matters because today’s users expect near-instant access to information, especially on mobile devices. If your site takes more than a few seconds to load or behaves erratically, visitors might not stick around long enough to explore your content or services. 

Optimizing front-end performance is key to improving user experience and keeping people engaged with your site.

What Does One Mean By Front End? Front End vs Back End

person infront of laptop - Front End Performance

When creating a seamless and efficient user experience, understanding the distinction between frontend and backend performance is critical. Both play a crucial role, not just in how a platform functions but also in how users perceive and interact with it.

Visual Elements

Frontend performance focuses on everything the user directly interacts with—a website or application's visual and interactive elements. This includes:

  • How quickly a page loads
  • How smoothly animations run
  • How fast the site responds to user inputs

Essentially, it’s all about the user experience.

User Retention

Frontend performance is directly tied to user retention and satisfaction. Studies show that 88% of users are less likely to return to a site after a negative experience, while 53% will abandon a site if it takes more than three seconds to load. 

This is why frontend performance testing is essential—it allows developers to measure and improve key metrics like:

  • Page load time
  • Responsiveness
  • Overall user experience

Backend Performance

Backend performance deals with the behind-the-scenes aspects of a website or application, everything that happens on the server side. This includes:

  • Databases
  • APIs
  • Server logic
  • Other processes that are not directly visible to the user but are crucial for the functionality of the front end

Backend Impact

The backend is the engine that drives the front end. If the backend is slow or unresponsive, it doesn’t matter how well-optimized the front end is, users will still:

  • Experience delays
  • Empty pages
  • Failed transactions

While the front end displays a user’s shopping cart, the backend handles tasks like retrieving item data, processing payments, and updating inventories. If these backend processes are slow, the entire user experience suffers.

Key Backend Performance Considerations

Backend performance testing focuses on aspects like:

  • Database performance: How quickly and efficiently the database can retrieve and store data.
  • API response times: How fast can the backend process and respond to requests from the frontend?
  • Server logic: The efficiency of the code that runs on the server, ensuring it can handle complex tasks without causing delays.

Optimizing the backend is crucial for ensuring the front end delivers a smooth and fast user experience.

The Balance Between Frontend and Backend

While frontend and backend performance are distinct, they are deeply interconnected. A sluggish backend can still hinder a highly optimized front end, and a poorly performing front end can undermine a fast backend. 

To deliver a seamless user experience, both frontend and backend performance must be carefully managed and optimized.

Backend Optimization

For businesses looking to enhance their digital platforms, starting with backend performance testing is often recommended. Ensuring that the backend processes are efficient and reliable creates a solid foundation for the front end to deliver an exceptional user experience. 

JS logo

Related Reading

Why Is Front End Performance Monitoring & Optimization Crucial For Businesses?

woman sitting alone in office - Front End Performance

Front-end performance monitoring improves user experience and boosts business revenue. Imagine visiting a website and having to wait for the page to load. You would likely feel frustrated, and even if the website contained the information you needed, you might not even want to access it anymore.

User Psychology

This dissatisfaction stems from a basic human instinct. Waiting for a website to load triggers a fight-or-flight response in our brains that signals danger. This reaction is why visitors abandon slow-loading websites for faster alternatives, even when unaware of their actions. Users also associate website performance with business credibility. 

If your site is fast, they may think your operations need to be updated or that you cannot be trusted to handle their personal information. Monitoring front-end performance helps you optimize your website to improve user experience and prevent visitors from developing negative impressions of your business.

Why Website Speed Matters

Site speed is essential for various reasons, but here are the 3 most important ones:

1. Exceptional User Experience

When customers or visitors first access a website, they expect quick loading times, ideally within 3 seconds. A website must load swiftly every time it is accessed to consistently provide an impressive user experience to first-time visitors.

2. Optimized Conversions

Imagine that a one-second delay can lead to a 7% conversion reduction. For an eCommerce site that generates $100,000 in daily revenue, low site speed could result in over $2.5 million in lost revenue annually. 

See what happens if you make a 1-second speed improvement. According to Google, increasing site speed by this mere second can boost mobile conversions by as much as 27%.

3. Higher SEO Rankings

Google has made its preference for speedy websites. Higher rankings translate to increased organic traffic, a vital factor for business success. Bear in mind Google emphasizes that website owners should not sacrifice content quality or relevance in pursuit of faster load times.

Try Alerty 

Alerty is a cloud monitoring service for developers and early-stage startups, offering:

  • Application performance monitoring
  • Database monitoring
  • Incident management

It supports technologies like NextJS, React, Vue, and Node.js, helping developers identify and fix issues. 

  • Alerty monitors databases such as Supabase, PostgreSQL, and RDS
  • Tracking key metrics like CPU usage and memory consumption
  • It features quick incident management and Real User Monitoring (RUM) to optimize user experience
  • Its universal service monitoring covers dependencies like Stripe API, OpenAI, and Vercel 

Alerty uses AI to simplify setup, providing a cost-effective solution compared to competitors. It is designed for ease of use, allowing quick setup, and integrates with tools like Sentry, making it ideal for developers and small teams needing efficient, affordable monitoring. 

Catch issues before they affect your users with Alerty's free APM solution today! 

Related Reading


What Are Core Web Vitals?

woman near a server room - Front End Performance

Core Web Vitals are key metrics introduced by Google in May 2021 that have become crucial for ranking websites in search engines. Think of them as guidelines that help ensure your website is fast but also user-friendly and stable. Let’s break down what these metrics are and why they matter.

What Are Core Web Vitals?

Core Web Vitals focuses on three specific aspects of the user experience:

  • How quickly your site loads
  • How quickly it becomes interactive
  • How visually stable it is as it loads

Each of these metrics plays a critical role in front-end optimization (FEO), ensuring your site runs smoothly for visitors.

The Three Key Metrics

Largest Contentful Paint (LCP)

LCP measures how long it takes for the most significant content on your page to load. This could be:

  • An image
  • A video
  • A large block of text

A fast LCP means that users see the main content quickly, which keeps them engaged and reduces the chance of them bouncing off to another site.

First Input Delay (FID)

FID tracks how quickly your site responds when a user first tries to interact with it. When someone clicks a button or a link, FID measures the time it takes for the site to start processing that interaction. 

A low FID is crucial because it ensures your site feels responsive, which is key to keeping users happy and engaged.

Cumulative Layout Shift (CLS)

CLS measures the visual stability of your site as it loads. Have you ever tried to click on a button, but just as you’re about to, the whole layout shifts, and you end up clicking something else? 

That’s what CLS is all about. A low CLS means your site’s layout remains stable while loading, providing a smoother, more pleasant user experience.

Why Core Web Vitals Matter

These metrics aren’t just about making your site faster—they’re about improving it for your users. Since Google uses Core Web Vitals to help determine search rankings, optimizing these metrics can boost your site's search engine visibility.

Vector

How To Check Frontend Performance?

woman focused on work - Front End Performance

PageSpeed Insights: The Go-To Tool For Frontend Performance

PageSpeed Insights offers a clear, easy-to-understand introduction to frontend performance and how to improve it. You simply enter your website’s URL, and it generates a report on various performance metrics, including the all-important Core Web Vitals. 

It’s powered by Lighthouse, a well-known tool for auditing web performance, so you can trust the results.

Chrome DevTools: The Power Tool for Frontend Performance Monitoring

Chrome DevTools is a powerful option for developers looking for something more hands-on. You can access it right from your Chrome browser by opening the:

  • DevTools panel
  • Heading to the Audits tab
  • Running a performance test

This tool also uses Lighthouse in the background, but it offers more detailed insights than PageSpeed Insights. It’s particularly useful during local development when you must fine-tune performance before pushing changes live.

Search Console Report (CrUX Data Set): The Frontend Performance Tool for SEO Junkies

For those who want to monitor their site’s SEO performance closely, Google Search Console is a must. If you haven’t already done so, add your website to Search Console. This tool provides detailed reports on your website’s performance in search results, including how it ranks for specific keywords and fares in Core Web Vitals. 

The data here comes from the Chrome User Experience Report (CrUX), which means it’s based on real user data. This can be incredibly useful for understanding how your site performs in the wild, not just in a controlled testing environment.

WebPageTest.org: Get Detailed Insights About Frontend Performance

If you need even more detailed performance insights, WebPageTest.org is an excellent resource. This online tool allows you to test your website from different locations worldwide, which is especially helpful if you have a global audience. 

The reports you get from WebPageTest.org are highly detailed, showing you everything that happens during a page load. This is perfect for debugging specific issues affecting your site’s performance.

GTmetrix: A Comprehensive Frontend Performance Analysis Tool

GTmetrix is another top-notch performance analysis tool. It provides a comprehensive breakdown of your site’s speed and offers actionable recommendations to improve it. Some of its standout features include:

  • Speed Visualization
  • A Waterfall Chart
  • The option to view a video of your page load process if you’re a paid user

GTmetrix is particularly useful for ongoing performance monitoring and optimization.

Web Vitals JavaScript Library: Monitor Frontend Performance in Real Time

If you want to track frontend performance for your actual users, the Web Vitals JavaScript library is a great option. This library lets you monitor Core Web Vitals (LCP, FID, and CLS) in real-time as users interact with your site. 

You can easily integrate it with your existing frontend setup and send the data to an analytics platform like Google Analytics. This gives you a clear picture of how your site performs for your entire user base, and you can even correlate these metrics with business outcomes like conversion rates.

13 Front End Performance Optimization Best Practices For Improving Site Performance

woman checking site vitals - Front End Performance

1. Clean Up the HTML Document 

HTML serves as the backbone of nearly every website. It allows you to format web pages with:

  • Headings
  • Subheadings
  • Lists
  • Other useful text-organizing features

With the most recent updates in HTML5, you can also create attractive graphics. Web crawlers can easily read HTML so that search engines can be updated with your website’s content promptly. 

HTML Best Practices

When dealing with HTML, you should write in a manner that is both concise and effective. When it comes to referencing other resources within the HTML document, there are a few best practices you should follow.

Proper CSS placement

Web designers create CSS style sheets after the main HTML skeleton of a webpage has been made. As such, CSS components are sometimes placed near the bottom of the document. It is recommended to put CSS at the top of your HTML document’s header to ensure progressive rendering. 
 
This strategy will not improve your website's loading speeds but will keep your visitors from waiting on blank screens or seeing a flash of unstyled text (FOUT). If most of your web page’s visual elements are already loaded, visitors will be more likely to wait for the entire page to load, thus improving your front-end optimization. This goes hand-in-hand with perceived performance.

Proper JavaScript placement

On the other hand, if you place JavaScript attributes within the head tag or near the top of the HTML document, you will block the loading process of:

  • HTML 
  • CSS elements

Script Placement

This mistake can cause visitors to wait on a blank page and, therefore, may impatiently abandon your site. You can avoid this issue by placing JavaScript attributes at the bottom of your HTML.

Async Loading

When using JavaScript, you should always prefer async script loading. This will prevent any <script> tags from blocking the HTML rendering process if it does come across one in the middle of the document, for instance. While HTML is one of the most valuable tools for web designers, it is often used with CSS and JavaScript attributes that can slow down your webpage. CSS and JavaScript attributes can transform your web pages for the better, but you should take special care and use them appropriately. 

A good practice with CSS and JavaScript is to avoid embedding the code. When you embed code, you place CSS in a style tag and use JavaScript in script tags. This increases the amount of HTML code that must be loaded each time your webpage is refreshed.

2. Reducing HTTP Requests

When loading a web page, a browser has to open a separate TCP connection for each HTTP request made, equal to the amount of page elements required to download. The problem is that there is a limit to the number of concurrent connections a browser can open to a single host. This limit protects a server from being overloaded with many HTTP requests.

Resource Management

It is also a potential bottleneck, often forcing the browser to start queuing connection requests. As the maximum connection threshold is quickly reached, various FEO techniques are employed to minimize the number of individual page elements. One of the most common is resource consolidation, which involves bundling together multiple smaller files. 

Say your website template consists of one HTML file, two CSS files, and 16 images, including:

  • Your logo 
  • Menu backgrounds

Connection Optimization

A browser needs to make 19 HTTP requests to load an empty page on your site. A visitor using the Google Chrome browser can only open six TCP connections to your server simultaneously, so the browser must queue the remaining 13 requests. 

If you consolidate all template images into a single sprite image, you can reduce the number of requests from 19 to just four. This lets Chrome parse the page in one sitting and reduces the number of round trips needed to load the page.

3. Optimize CSS Performance

You can use CSS or cascading style sheets to change your HTML-based information into a neat, polished document. Many CSS settings need HTTP queries (unless you use inline CSS) to reduce bloated CSS files without sacrificing essential functionality. 

If the link styles for your layout, plugin, and banner are all contained in different CSS files, your visitors’ browsers will have to load many files at once. This old-fashioned technique prohibits browsers from carrying out concurrent downloads. The link tag is the best option, which will enhance your website's front-end functionality.

4. Optimize Images and Videos

Images are often the most extensive files on a webpage and can significantly impact loading speed. By optimizing images for the web, you can reduce their file size without compromising on quality. Start by resizing images to the dimensions displayed on your website. Avoid uploading large images and relying on the browser to resize them.

Image Optimization

Compress images using tools or plugins that can reduce file size without noticeable loss in quality.  Consider using modern image formats like WebP or AVIF, which offer better compression and faster loading times than traditional formats like:

  • JPEG 
  • PNG

Lazy loading techniques defer loading images that are not immediately visible, reducing the initial page load time.

5. Enable Prefetching

Resource prefetching is another performance-improving method for increasing front-end data loading. There are mainly three types of prefetching:

Link Prefetching

By using link prefetching, a browser can gather the resources a user will need shortly. Developers can predict where consumers are likely to visit a particular webpage.

DNS Prefetching

A DNS search is carried out whenever a user requests an asset hosted in a specific IP address to identify the domain name to which the IP address belongs. By enabling DNS prefetching, the browser can look up the Domain Name System for any links in the webpage in the background.

Prerendering

With prerendering, the content is pre-downloaded and invisibly processed in the browser as if the data were displayed on a different tab.

6. Implementing Browser Caching

Browser caching allows storing static files, such as:

  • CSS
  • JavaScript
  • Images on a user’s device

Enabling caching can reduce the number of browser HTTP requests and improve the loading speed for returning visitors. To implement browser caching, set appropriate cache headers on your server. 

These headers inform the browser how long it can cache specific files before requesting them again. Consider setting a longer cache time for static files that rarely change and a shorter cache time for frequently updated files.

7. Minifying and Compressing Files

Minifying and compressing files can significantly reduce size, leading to faster loading times. Minification involves removing unnecessary characters, such as whitespace and comments, from:

  • CSS 
  • JavaScript files

Several tools and plugins can automatically minify your files during the build process. Additionally, consider using Gzip compression to reduce file sizes further. Gzip compresses files before sending them to the browser, reducing the amount of data that needs to be transferred.

8. Using Content Delivery Networks (CDNs)

Content Delivery Networks (CDNs) can significantly improve your website’s loading speed by distributing your content across multiple servers in different locations. When a user requests your website, the CDN serves the content from the server closest to their location:

  • Reducing latency 
  • Improving loading times

To use a CDN, you typically need to upload your static files to the CDN provider’s servers and configure your website to fetch these files from the CDN instead of your origin server. Popular CDN providers include:

  • Cloudflare
  • Amazon CloudFront
  • Akamai

9. Evaluate Your Hosting Provider

Your web hosting provider could be a source of speed-related issues. Speed problems may stem from various factors, including:

  • Your provider's geographical location
  • The quality of its physical infrastructure
  • The overall bandwidth of its network connection

The type of web hosting your website utilizes can also significantly impact its performance. 

There are three common hosting types:

  • Shared
  • VPS (Virtual Private Server)
  • Dedicated hosting

Hosting Limitations

Shared hosting options are the most cost-effective but have a downside. They distribute hosting resources among multiple websites, which can reduce overall performance. This becomes particularly problematic if your site experiences spikes in traffic or consistently high traffic levels. 

Virtual Private Server (VPS) options logically segment services on a shared physical drive to enhance performance. They can still encounter speed issues when resource demands are high.

10. Enable Asynchronous Loading for JavaScript Files 

Many websites load JavaScript content sequentially, from top to bottom, causing a render-blocking effect where each file waits its turn. This sequential loading can slow down the entire webpage, even when the user’s browser can handle multiple HTTP requests simultaneously. 

Asynchronous JavaScript

Configuring your website to load JavaScript asynchronously can improve the user experience. This approach allows various page elements to render simultaneously, regardless of their position on the page. 

WordPress offers numerous plugins to help implement asynchronous loading. HubSpot provides options to customize the rendering of your webpage's popular JavaScript element, jQuery, eliminating the need to wait for it to load.

11. Track 404 Errors

To identify and rectify a 404 error, you can employ error detection tools and plugins. It’s worth mentioning that adding extra plugins can have a detrimental impact on your website’s speed. We recommend using external tools for error detection, such as Google Webmaster Tools (GWT).

Error Impact

Once you’ve identified all the 404 errors, assessing the traffic they generate is crucial. If these dead links no longer attract visitors and do not consume your server resources, you may leave them as they are. 

If these pages continue to receive traffic, it’s advisable to set up redirects for external links and correct the link addresses for internal ones. This ensures a smoother user experience and maintains the integrity of your website.

12. Use a Minimalistic Framework  

You need to build your website solely with your coding knowledge to avoid many amateur frontend optimization mistakes using a good front-end framework. Although some larger, more well-known frameworks come with additional features and options, your web project may only require some. 

That's why it's important to determine what features your project requires and start with a framework that can provide those features while remaining lightweight. Some of the most recently designed frameworks use:

  • Concise HTML
  • CSS
  • JavaScript code

Framework Limits

A framework is not a replacement for careful web design, programming, and maintenance. For simplicity, imagine that the framework is a new house. The house is clean and presentable, but it is also empty. You must ensure the house is clear when you add furniture, appliances, and decorations. 

Likewise, it is your responsibility to ensure that the framework is not ruined by:

  • Redundant codes
  • Large images
  • Excessive HTTP requests

13. Remove Unnecessary Custom Fonts

Custom fonts are popular today since they help make websites more distinctive. However, they have a performance cost. These may be rather hefty, and web fonts like Google fonts include HTTP calls to external resources, slowing down page rendering. 

While employing fonts on your website, you can: 

  • Choose the most effective font format: Compared to other formats, loading a contemporary format like WOFF2 can reduce the file size by about 30%. 
  • Eliminate superfluous characters: Subset fonts include characters for numerous languages that may never be used in comprehensive font files. 

By subsetting typefaces, you can stop extraneous characters from the font and retain only those required to compose website content. Preload the fonts that the page explicitly specifies.

Alerty-Logo dk

6 Frontend Performance Monitoring Tools You Can Use

woman with laptop - Front End Performance

1. Alerty

Alerty is a cloud monitoring service for developers and early-stage startups, offering:

  • Application performance monitoring
  • Database monitoring
  • Incident management

It supports technologies like NextJS, React, Vue, and Node.js, helping developers identify and fix issues. 

  • Alerty monitors databases such as Supabase, PostgreSQL, and RDS
  • Tracking key metrics like CPU usage and memory consumption
  • It features quick incident management and Real User Monitoring (RUM) to optimize user experience
  • Its universal service monitoring covers dependencies like Stripe API, OpenAI, and Vercel 

Alerty uses AI to simplify setup, providing a cost-effective solution compared to competitors. It is designed for ease of use, allowing quick setup, and integrates with tools like Sentry, making it ideal for developers and small teams needing efficient, affordable monitoring. 

Catch issues before they affect your users with Alerty's free APM solution today!

2. Google Lighthouse: The Open-Source Tool for Website Audits

Google Lighthouse is a free, open-source tool perfect for anyone who wants to analyze their website’s performance. It’s not just for performance monitoring—it also audits aspects like accessibility, SEO, and progressive web app (PWA) best practices. 

The great thing about Lighthouse is that it provides an overall performance score and actionable recommendations to improve your site. You can run it directly in Chrome’s DevTools, through the command line, or via its web interface. If you’re looking for a well-rounded audit of your front-end, Lighthouse is a must-have.

3. Sentry: The Open-Source Performance Monitoring Tool for Error Tracking

Sentry is another powerful tool, especially for developers who want to track errors and performance issues in their front-end code. It’s an open-source platform that goes beyond just performance monitoring, it’s built to help you detect and fix bugs that might be affecting users. 

Sentry’s transaction tracing feature allows you to trace specific requests through your front end, giving insights into potential bottlenecks. This tool is ideal for teams with real-time error tracking and performance monitoring.

4. Pingdom: The Monitoring Tool for Real User Data

Pingdom is best known for its uptime monitoring capabilities, but it also shines in front-end performance monitoring. One of its key features is real-user monitoring (RUM), which tracks actual user interactions and provides detailed reports on site speed and performance from the user’s perspective. 

Pingdom also offers customizable alerts and can monitor things like SSL certificates and DNS health, making it a versatile tool for performance monitoring. It’s an excellent choice for businesses that want to ensure their site is up and running smoothly at all times.

5. Sematext: The Comprehensive Performance Monitoring Solution

Sematext provides an all-in-one monitoring solution for front-end developers. It focuses on real-time alerts, integration with major frameworks, and log management. It’s ideal for teams that want a comprehensive overview of their site's performance in production environments. 

You can monitor key metrics like page load time and Core Web Vitals, and it integrates seamlessly with other tools you might already be using. The unified dashboard makes it easy to keep track of multiple aspects of your site’s health, from logs to performance metrics.

6. LogRocket: The User Session Replay Tool for Front-End Monitoring

While not a traditional performance monitoring tool, LogRocket offers valuable insights into how users interact with your website. It captures user sessions, allowing you to see what users experience as they browse your site. 

You can track JavaScript errors, network requests, and performance issues, which makes it easier to pinpoint where something might be going wrong. Although it’s primarily focused on user behavior and error tracking, LogRocket can still provide valuable data about your front-end's performance.

Catch Issues Before They Affect Your Users with Alerty's Free APM Solution

Web performance is a critical part of user experience. When a user lands on your website or web app, two key metrics determine their experience: 

  • First Contentful Paint (FCP) 
  • Time to Interactive (TTI)

The faster your site can render content and become interactive, the better. No one likes a slow site. Studies show that 47% of users expect a web page to load in two seconds or less. If it takes longer than that, they will likely leave. 

Your site’s performance also affects SEO rankings. Google has consistently said that site speed is a ranking factor. With the core web vitals update, the search engine is looking at real user measurements to determine rankings. Monitoring frontend performance will help you retain your users and impress the search engines.

Related Reading

Group 21