Total Blocking Time (TBT)

Total Blocking Time (TBT) measures the total amount of time during which a page is blocked from responding to user interactions, such as clicks, taps, or keyboard input. TBT is an important performance metric because it directly impacts how responsive and interactive a page feels to users.

What is Total Blocking Time?

Total Blocking Time is calculated by summing up all periods where the main thread is busy, blocking user input. It measures the time between First Contentful Paint (FCP) and Time to Interactive (TTI) during which the browser is unable to respond to user inputs due to long tasks (tasks that take more than 50 milliseconds).

Why TBT Matters for Page Speed

A high Total Blocking Time means that users might experience delays in their interactions with the page, which can lead to a frustrating user experience. When users cannot interact with a page promptly, it can result in increased bounce rates and reduced engagement, making TBT a critical metric for evaluating a page's responsiveness.

Impact on SEO

Search engines prioritize user experience in their ranking algorithms. A page with a high Total Blocking Time can negatively impact SEO by providing a subpar user experience. Websites that are slow to respond to user interactions may see reduced search engine rankings and decreased traffic.

How to Improve Total Blocking Time

To reduce Total Blocking Time and improve page responsiveness, consider the following strategies:

  • Minimize Long Tasks: Break up long tasks into smaller, asynchronous tasks to prevent the main thread from being blocked for extended periods.
  • Optimize JavaScript Execution: Reduce the amount of JavaScript that needs to be executed on page load, and defer or asynchronously load scripts when possible.
  • Implement Web Workers: Offload resource-intensive tasks to web workers, which run in the background and do not block the main thread.
  • Reduce Main Thread Work: Optimize and streamline the tasks that run on the main thread to decrease blocking times and improve responsiveness.
  • Use Code Splitting: Split your code into smaller chunks that can be loaded on demand, rather than loading all code upfront.

Improving Total Blocking Time contributes to a more responsive user experience and can positively affect your page's SEO performance. By addressing TBT, you can create a faster, more interactive website that keeps users engaged.

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Speed Index

Measures how quickly the content of a page is visually displayed. A good Speed Index is less than 4.3 seconds.

Internal and External Links

The number of links within your site and to other websites.

Largest Contentful Paint (LCP)

Measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading.

Core Web Vitals

We measure key performance metrics to ensure a good user experience.

Cumulative Layout Shift (CLS)

Measures visual stability. To provide a good user experience, pages should maintain a CLS of less than 0.1.

Keyword Density

The frequency of single words and two-word phrases, helping you understand your content focus.

First Input Delay (FID)

Measures interactivity. To provide a good user experience, pages should have an FID of less than 100 milliseconds.

First Contentful Paint (FCP)

Marks the time at which the first text or image is painted. FCP is an important, user-centric metric for measuring perceived load speed.

Headings

We analyze the structure and count of your H1, H2, and H3 tags.

Images

We count the total images and those with alt text, which is important for accessibility and SEO.

Total Blocking Time (TBT)

Measures the total amount of time that a page is blocked from responding to user input, such as mouse clicks, screen taps, or keyboard presses.

Page Speed Analysis

We evaluate several metrics that affect your page's loading speed and user experience.

SEO Score

An overall rating of your website's SEO health, calculated based on various factors.

SSL Certificate

We check if your site uses HTTPS, which is important for security and SEO.

Time to Interactive (TTI)

Measures how long it takes for the page to become fully interactive. A good TTI is within 5 seconds of page load.

Title and Meta Description

We check if your page has a title and meta description, and evaluate their length and relevance.

Broken Links

We identify any broken links on your page, which can negatively impact user experience and SEO.

Top Words

The most frequently used words on your page, which can indicate your main topics.

Word Count

The total number of words on your page. Search engines generally prefer content-rich pages.

Use this information to optimize your website, improve your search engine rankings, and provide a better experience for your visitors.