What is Interaction to Next Paint (INP), and How to Optimize It

What is Interaction to Next Paint (INP), and How to Optimize It

Interaction to Next Paint (INP) is a Core Web Vitals (CWV) metric to measure the web page’s interactivity for user experience quality. INP is a user-centric page speed metric that affects search engine optimization performance, conversion rate, and user satisfaction. Interaction to Next Paint replaced First Input Delay (FID) in March 2024 in Core Web …

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“link rel=preload”: How to Preload Key Requests with Browser Hints

Preload Resources

“Link rel=preload” is a browser hint to provide resource loading prioritization to improve the web page loading performance and speed. Preload is a value for the “rel” attribute of the HTML “link” tag to fetch a web page resource earlier than others. To improve the initial contact with users by improving the user experience, preload …

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User-centric Web Page Speed Performance Metrics

User Centric Performance Metrics

User-centric web page speed performance metrics focus on different verticals that affect the perception of users for the page loading performance of a website. User-centric performance metrics are announced by Google Developers and W3C Web Performance Working Group to organize the concepts that are related to the Lighthouse. User-centric performance metrics involve the relativity of …

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What is the Expires HTTP Header?

Expires HTTP Header

HTTP Expires Header is a header that provides the date and time for specifying the limit for the response’s content staleness. This header can be set by either server or client, depending on who sends it first. It can also be sent in case of no other headers are specified. This type of request/response specifies …

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Cache-Control HTTP Response Header

Cache-control HTTP Header

Cache-control is an HTTP response header to determine browser caching time span for a specific web page resource. Cache-control includes a resource’s caching methodology, where to cache, and its expiration date with maximum age (time to live). Cache-control HTTP Header regulates browser caching policies for clients. Examples for Cache-Control Response Header Cache-control example values and …

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What is TCP Slow Start?

TCP Slow Start

Transmission Control Protocol (TCP) is a connection balancing algorithm that controls the number and speed of connections a server can open and protects the server. In order to avoid overloading a network with an unexpectedly large burst of data, TCP slow start probes the network slowly to confirm the available capacity. During the beginning of …

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What is HTTP Etag?

Entity Tag Definition

The ETag HTTP response header is a qualifier for determining version of a web page resource from a website’s server that requested by the requestor which is a web browser user. ETag is used for efficient browser cache in order to decrease bandwidth consumption. If a website uses ETag for its web page resources, the …

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Specify a Vary: Accept-Encoding Header: Understanding The HTTP Vary Header

HTTP Vary Conditional Request

The HTTP Vary Response Header is used to indicate which type and format of content are requested from the web site’s server via the browser. This process performed through HTTP Vary Header is called “Content Negotiation”. In the RFC7232 Document, Hypertext Transfer Protocol (HTTP / 1.1), this case is called “Conditional Requests”. Accordingly, when entering …

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What is Total Blocking Time and How to Optimize It?

Total Blocking Time Optimization

Total Blocking Time (TBT) is a load responsiveness metric that measures the usability of the web page during the loading. Total Blocking Time is an important user-centric performance metric that compares the time amount of non-responsive and responsive time during the rendering phase of the web page. Input responsiveness or the interactivity between the web …

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What is Time to Interactive (TTI) and How to Optimize It?

Time to Interactive Definition and Optimization

Time to Interactive (TTI) is the performance metric that measures when the web page’s subresources have been downloaded and when the user can interact with the web page. Time to Interactive is not just about “loading responsiveness”. It is also about the “downloading the main resources of the web page”. To measure and understand the …

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