Author Addy Osmani

September 29, 2021 — In this article, we’ll highlight how modern image formats (AVIF or WebP) can improve compression by up to 50% and deliver better quality per-byte while still looking visually appealing. We’ll compare what’s possible at high-quality, low-quality and file-size targets. Read more…

April 29, 2021 — Images have also been a key part of the web. They communicate ideas instantly, but they are also a lot heavier than text to load. This means that it’s essential to get loading and displaying them right, if you want to give your users a fantastic first impression. An excerpt from Addy’s new book (also, check a free PDF preview). Read more…

April 23, 2021 —

Images have always been a key part of the web. Our brains are able to interpret images much faster than text, which is why high-quality visuals drive conversions and user engagement.

That said, loading images efficiently at scale isn’t a little project for a quiet afternoon. It requires understanding of compression techniques, loading behavior, image decoding and image CDNs, adaptive media loading and caching.

This book will equip you with everything you need to know to optimize how you compress, serve and maintain images — boosting performance along the way. Jump to table of contents.

528 pages. High quality hardcover + eBook (PDF, ePUB, Kindle). Written by Addy Osmani. Shipping now.

June 10, 2013 — Today we’ll discuss how to improve the paint performance of your websites and Web apps. This is an area that we Web developers have only recently started looking at more closely, and it’s important because it could have an impact on your user engagement and user experience. Read more…

December 22, 2012 — Many of us care deeply about developing our craft. But staying up to date can be a true challenge, because the quantity of fresh information we’re regularly exposed to can be a lot to take in. 2012 has been no exception, with a wealth of evolution and refinement going on in the front end. Read more…

November 5, 2012 — JavaScript engines such as Google’s V8 (Chrome, Node) are specifically designed for the fast execution of large JavaScript applications. As you develop, if you care about memory usage and performance, you should be aware of some of what’s going on in your user’s browser’s JavaScript engine behind the scenes. Read more…

July 27, 2012 — When writing a web application from scratch, it’s easy to feel like we can get by simply by relying on a DOM manipulation library (like jQuery) and a handful of utility plugins. The problem with this is that it doesn’t take long to get lost in a nested pile of jQuery callbacks and DOM elements without any real structure in place for our applications. Read more…

November 30, 2011 — Many of us rely on open source tools, technologies and standards to help improve the work we do on a daily basis. None of this would however be possible without the hard work, commitment and dedication that others, just like you, have invested in giving back to the Web community over the past two decades. Read more…

October 27, 2011 — Before we start, I’d like to pose a question: when was the last time you asked someone to review your code? Reviewing code is possibly the single best technique to improve the overall quality of your solutions, and if you’re not actively taking advantage of it, then you’re missing out on identifying bugs and hearing suggestions that could make your code better. Read more…

October 11, 2011 — I occasionally write about implementing design patterns in JavaScript. They’re an excellent way of building upon proven approaches to solving common development problems, and I think there’s a lot of benefit to using them. But while well-known JavaScript patterns are useful, another side of development could benefit from its own set of design patterns: jQuery plugins. The official jQuery plugin authoring guide offers a great starting point for getting into writing plugins and widgets, but let’s take it further. Read more…

September 2, 2011 — In this multi-part post, Addy Osmani takes you through the exact set-up he uses to accurately test content that will be potentially viewed by up to millions of users with a very diverse set of browsers. Read more…

January 1, 0001 —

Images have always been a key part of the web. Our brains are able to interpret images much faster than text, which is why high-quality visuals drive conversions and user engagement.

That said, loading images efficiently at scale isn’t a little project for a quiet afternoon. It requires understanding of compression techniques, loading behavior, image decoding and image CDNs, adaptive media loading and caching.

This book will equip you with everything you need to know to optimize how you compress, serve and maintain images — boosting performance along the way.