It takes about 50 milliseconds for page visitors to form a first impression of your website. This split-second period determines whether online users stay on your page or leave. Does your website have a responsive web design? Protect your site from Google penalties and reduce your bounce rate by maintaining a good First Input Delay (FID) score.
What is FID and how does it affect your online ranking and visitors’ first impression?
First Input Delay is one of the Core Web Vitals metrics, along with Cumulative Layout Shift (CLS) and Largest Contentful Paint (LCP), that are set to be significant ranking factors. Google FID measures a web page’s interactivity and assesses users’ first interaction experiences on the web.
But what is First Input Delay, and how much input lag is too much? Learning the answers to these questions will help you take the first step towards reducing FID on your website and increase your chances of achieving a good Google FID score. Discover what is FID, how to measure First Input Delay and how to optimize for FID.
Find out what is FID and how to measure input lag to strengthen your responsive website design and technical SEO strategies.
What Is First Input Delay?
First Input Delay is a Core Web Vitals metric that measures the input delay – the time between the user interaction and when the browser starts processing event handlers in response to user input. Event handlers are scripts embedded in website documents as HTML attributes to manage every user action, user input or browser action.
Google FID determines the input delay for every discreet action a user takes, such as a click, a tap or a keypress. Scrolling and zooming the page are not considered in the FID test because these are continuous actions with different performance constraints.
Why the First Input?
Long input delays typically occur between the First Contentful Paint (FCP) – the time a browser renders the first piece of content (i.e., canvas render, text, image, etc.) – and Time to Interactive (TTI), when the web page becomes ready for interaction.
The FID test focuses on the first interaction since it is usually when the browser is busiest in parsing and executing various large JavaScript being loaded on your website. By default, a browser uses the main thread to run all the JavaScript on your page. The busier the main thread, the longer input delay you can expect.
However, FID and Time to Interactive may not always be directly correlated. To better understand the goal of the input delay test, let’s look at the correlation between Google FID and TTI:
The relationship between Google FID and TTI:
- Time to Interactive can be calculated without real user metrics since it measures the time it takes for a web page to be ready for interaction.
- A web page may have a slow Time to Interactive, but as long as users are not trying to interact with it immediately, FID may still be fast.
- A user on a low-end device with a slow central processing unit (CPU) may also experience longer TTI and worse FID than the average First Input Delay.
- A page with no input gestures at all will have no FID.
Why Does FID Matter to
Page Experience Update?
WordPress sites and other websites powered by different content management systems (CMS) are more dynamic and touch-driven than ever before. That is why users expect a more interactive and responsive website experience.
To meet user expectations and convince them to stay on a web page, web developers and site owners must focus on reducing FID on WordPress sites. An FID score above the average First Input Delay could make your website feel clunky, resulting in a negative user experience.
Additionally, knowing how much input lag is too much and how to optimize for First Input Delay are critical to responsive web design and technical SEO services because:
Reducing First Input Delay WordPress sites increases site usability and interactivity.
Online users expect a response within a fraction of a second.
Understanding what is a good FID score and how to measure input lag is significant in creating a responsive website design.
Page visitors get easily frustrated with sluggish or unresponsive website designs.
Failure to learn how to optimize for FID may result in lower website rankings, increased bounce rates and reduced page sessions.
FID issues can affect your paid campaigns, internal linking ability and overall return on investment (ROI).
To optimize First Input Delay, it is imperative that you understand the basics of measuring FID and reducing FID WordPress sites. Let’s look at how to measure First Input Delay, what is a good FID score and how to improve First Input Delay.
-
The webpage
starts loading -
The user taps the
sidebar to access other
website content. -
The browser disregards
the initial user interaction
and is still busy loading a large element. -
Once the large element is loaded, this is only when the browser begins processing the interaction with the sidebar.
How to Measure First Input Delay
First Input Delay is a field metric. This means it requires real user input to perform input delay tests and collect data on how to improve FID.
As for how to measure input lag?
Responsive web design and technical SEO services providers use the following FID test tools in measuring First Input Delay:
To determine the long tasks that cause input delay during the web page loading process, Google also looks at the Total Blocking Time (TBT).
TBT is a lab metric that measures a website’s load responsiveness. Technical SEO and web design optimization efforts that improve TBT in the lab also optimize First Input Delay for online users.
Besides measuring First Input Delay, a technical SEO agency must also determine all types of input – from the instant ones that don’t hit a blocking task to the ones that encounter a delay – to streamline efforts in reducing FID on a website.
Technical SEO services providers recommend using the following tools to determine the different types of user input:
Technical SEO services providers recommend using the following tools to determine the different types of user input:
Ready to optimize First Input Delay? Once you know how to measure FID, the next step is to perform an input delay test on your web pages and begin your FID optimization process. Read on to learn what is a good First Input Delay score, how much input lag is too much and how to optimize for FID.
What Is a Good FID Score
Fifty milliseconds is enough time for the browser and the main thread to load and react visually to user input. Every millisecond after that is considered a potential blocking time that can cause a slow FID.
What Is a Good First Input Delay Score?
Users perceive a response time of 100 milliseconds or less to be instantaneous. This means a technical SEO agency should aim for an average First Input Delay of not more than 0.1 second for all web pages:
< 100 ms
Good User Experience
100-300 ms
Needs Improvement
> 300 ms
Poor User Experience
To ensure you’re hitting the ideal First Input Delay score, be sure to check if at least 75 percent of your user inputs fall into the fast bracket. This is a good indication that you’ve mastered how to improve First Input Delay and your website provides a good user experience.
What Influences FID?
In some cases, users may experience longer or shorter FID or no delay at all. This is because First Input Delay varies depending on when a user interacts with a web page. Some users scroll first before tapping on a button, while others are impatient in pressing a key or navigating another page.
More Factors Affecting How to Improve FID:
- Long-running JavaScript functions that block the main thread
- Third-party codes
If your FID is longer than 300 milliseconds, it’s high time that you learn how to optimize First Input Delay and work on your website issues.
How to Improve First Input Delay
It takes approximately 28 days for Google to crawl and approve newly optimized pages for Core Web Vitals. Approval is only attained if throughout the 28 days during which Google monitors your site, there are no concerns. Begin your FID optimization efforts now to improve your Core Web Vitals and give your website a good online reputation.
Don’t know how to measure First Input Delay and how to improve FID? Here are some tips on how to optimize First Input Delay to ensure your technical SEO and responsive web design efforts result in a good FID score:
- Perform a comprehensive website audit to determine FID and other Core Web Vitals issues.
- Reduce the third-party code.
- Clean your code profiling. Be sure to remove unused codes from your files.
- Deque the unused files according to the pages.
- Optimize your internal linking.
- Monitor your site performance using the input delay test tools mentioned earlier.
- Run simulations on real devices and different connection types.
- Optimize your files without interfering with valuable site functionalities.
- Reduce main bundle size.
- Apply code-splitting at the component level.
- Optimize the hydration step of your website to knock 100 milliseconds off your TBT. Hydration focuses on placing event handlers to HTML elements to convert static web pages into dynamic websites. Keep in mind that this step may or may not be applicable, depending on your website.
Still in the dark on how to optimize for First Input Delay? Our technical SEO experts and web developers spent the last four months improving the Thrive website for Core Web Vitals. Our optimization efforts resulted in 0 poor URLs, 1,376 good URLs on mobile and about 92 percent of real user metrics with a good FID score.
Call our technical SEO agency at 866.908.4748 or fill out our contact form and let’s discuss how to optimize for FID using proven methods.