What Is Latency & How Do You Improve It in 2024?

If you want your website or application to provide a great user experience, minimizing latency is crucial. But what exactly is latency and how can you reduce it?

In this comprehensive guide, we‘ll dive deep into the topic of latency to understand what causes latency, why it‘s important, how to measure it, and most importantly – the steps you can take to improve latency and ensure your site is as responsive as possible for visitors.

What Is Latency?

In the context of websites and web apps, latency refers to the delay or lag between when a user takes an action, like clicking on a link or submitting a form, and when they receive a response. It‘s the total round trip time for data or requests to travel from the user‘s device to the web server and back.

You‘ve likely experienced latency yourself when trying to load a slow webpage. You click a link and then wait several seconds while the browser seems to hang before finally displaying the content. In this case, high latency is leading to long wait times and a poor user experience.

On the flip side, sites with low latency respond almost instantly to user actions, providing a snappy, seamless experience. Achieving low latency has become increasingly important, with users expecting pages to load within just 2-3 seconds on average.

Why Does Latency Matter?

Latency is one of the most important factors in overall website performance and user experience:

• High latency means longer page load times, which is a major frustration for users. 53% of mobile users abandon sites that take over 3 seconds to load.

• Even small delays of 100ms can impact customer satisfaction and conversion rates.

• Search engines like Google use page speed as a ranking factor, so poor latency hurts your SEO and organic traffic.

• For ecommerce sites, high latency has a direct impact on revenue, with a 1 second delay potentially reducing conversions by 7%.

In short, if you want to maximize user engagement, conversions, and search engine rankings, you need your site to have the lowest latency possible. Even seemingly minor improvements in latency can have a major positive impact.

What Causes Latency?

There are numerous factors that can introduce latency between a user requesting a web page and the browser displaying that page:

Physical Distance

The physical distance data has to travel between the end user‘s device and the web server is one of the biggest factors in latency. The further the distance, the more latency is introduced, no matter how fast the network connections are.

Network Quality & Speed

The quality and speed of the network connections between the client and server also play a major role. Inconsistent, congested, or low bandwidth networks will increase latency compared to fast, modern network infrastructure. The "last mile" connection to the end user is often the biggest bottleneck.

Web Server Configuration

The hardware and software powering your web server introduce latency. Underpowered servers with slow CPUs, low memory, or maxed out resources will be slower to process requests and respond compared to high-performance modern infrastructure. The web server software configuration and your backend code also impacts latency.

Page Weight

The amount of data required to load the page, known as the "page weight," is another factor. Pages consisting of large HTML, CSS and JavaScript files, uncompressed images, and lots of third-party scripts will have more latency than lightweight, optimized pages. More data takes longer to transmit and process.

Third-Party Services

Most modern sites rely on third-party services and content, such as ads, analytics, social media widgets, CDNs, and more. Each of these introduces additional network requests and potential points of latency outside of your direct control. Issues with a third-party provider can negatively impact your site‘s latency.

Measuring Latency

There are a few different ways to measure and benchmark your site‘s latency:

Round Trip Time (RTT)

RTT measures the total time for a request to travel from the client to your server and for the response to travel back. It includes both the "frontend" latency introduced by the network as well as the the "backend" latency introduced by your server processing the request.

Time to First Byte (TTFB)

TTFB measures the time between the client requesting a resource and when it receives the first byte of data in the response. This metric focuses more on the "backend" latency introduced by your web server and application.

Ideal Latency Targets

While the ideal latency depends on the type of site and audience, generally you should aim for:

• RTT: under 100 ms
• TTFB: under 1.3 seconds

You can use tools like Pingdom or GTmetrix to measure your site‘s latency from different locations around the world to get a realistic sense of what your users are experiencing.

How to Improve Latency in 2024

Now for the most important part – the steps you can take to improve your website or application‘s latency in 2024 and beyond:

1. Implement a Content Delivery Network (CDN)

A CDN distributes your site‘s static content across a network of servers located around the world. Users are served content from the data center closest to their physical location, dramatically reducing round trip times. For sites with geographically distributed users, a CDN is one of the most impactful ways to improve latency.

2. Optimize & Minify Resources

Optimizing your site‘s code and assets to reduce the overall page weight will improve latency. Minify HTML, CSS and JavaScript by removing unnecessary characters. Compress images and use modern efficient formats like WebP. Lightweight pages load much faster.

3. Enable Browser Caching

Configuring your server to enable browser caching means that the client can store copies of static resources locally and reuse them on subsequent page loads without having to request them again from your server. This reduces the data transferred and round trips required, improving latency.

4. Reduce Third-Party Scripts

Scripts, pixels, and other assets loaded from third-party domains each open new connections that introduce more latency. Audit and remove any third-party resources that aren‘t absolutely essential. For those that remain, see if you can self-host them or use resource hints like dns-prefetch.

5. Upgrade Server Hardware

The fastest way to improve backend latency is to upgrade to newer, higher-performance server hardware. Look for CPUs with fast clock speeds and modern architectures. Ensure that you have sufficient RAM for your application. Solid state drives can also help with read/write speeds.

6. Choose a Premium Hosting Provider

Your hosting environment has a huge impact on latency. Choosing a reputable managed hosting provider that offers modern, high-performance infrastructure will improve your latency compared to low-cost shared hosting. Look for premium Tier 1 networks, server-level caching, and other performance optimizations.

7. Monitor & Optimize Continuously

Maintaining low latency requires continuous monitoring and optimization as your site‘s traffic and requirements evolve. Use real user monitoring (RUM) tools to measure and benchmark latency and core web vitals over time. Prioritize incremental frontend and backend improvements to keep latency low.

Advanced Latency Optimization Techniques

For high-traffic sites or applications where every millisecond of latency counts, consider more advanced optimization techniques:

• Prefetching resources that are likely to be needed
• Lazy loading non-critical resources
• Exploring edge computing platforms like Cloudflare Workers and AWS Lambda@Edge
• Fine-tuning application and database query performance
• Implementing a service worker for offline caching

However, these advanced techniques are not a substitute for basic latency best practices. Walk before you run by focusing on the fundamentals first.

The Importance of Low Latency

Latency has always been important, but it‘s becoming absolutely critical to delivering a great user experience as user expectations rise and web apps become increasingly dynamic and sophisticated.

By taking a strategic approach to measuring and optimizing latency across both the frontend and backend, you can ensure that your site remains fast and responsive even as it grows in complexity. This will give you a significant advantage over competitors and position you to maximize user acquisition, engagement, conversions, and retention.

While achieving low latency isn‘t always easy, it‘s well worth the effort. Every incremental improvement can have an outsized impact on your site‘s performance and your business results. So if you want to set your site up for success in 2024 and beyond, make minimizing latency a top priority.