Time to Interactive (TTI)
Time to Interactive (TTI) is a web performance metric that measures the time it takes for a web page to become fully interactive and responsive to user input.
TTI is a critical indicator of a website or application's overall user experience, as it reflects how quickly users can meaningfully engage with the content on the page.
A faster TTI contributes to a more enjoyable and seamless user experience. To provide a good user experience, Google suggests sites should strive to have a TTI of less than 5 seconds when tested on average mobile hardware.
Improving Time to Interactive can be achieved through various optimization techniques including:
- Optimize critical rendering path: The critical rendering path is the sequence of steps a browser takes to process and render the first content on a page. Optimizing it, by minimizing render-blocking resources and reducing file sizes, can help improve TTI.
- Prioritize visible content: Prioritize rendering the content visible on the screen (above-the-fold) and defer the rendering of off-screen content. Techniques like lazy loading and content placeholders can help achieve this.
- Optimize CSS: Heavy CSS can impact TTI due to the time required for style calculations and layout. Minimize the complexity of your CSS selectors, avoid using expensive CSS properties, and remove unused styles to optimize rendering performance.
- Reduce server response time: A faster server response can help improve TTI by reducing the time it takes for a server to deliver the HTML document. Optimize server configurations, use a Content Delivery Network (CDN), and implement caching strategies to minimize server response time.
- Leverage browser caching: Cache static resources, such as images, stylesheets, and scripts, to decrease load times for repeat visits and improve TTI.
These are just a couple of suggestions on optimizing your TTI results. Get into performance-first mindset with our comprehensive frontend performance checklist.
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