Skip to Content
Designing for Performance
book

Designing for Performance

by Lara Callender Hogan
December 2014
Beginner to intermediate
179 pages
4h 11m
English
O'Reilly Media, Inc.
Content preview from Designing for Performance

Chapter 3. Optimizing Images

Images make up the majority of most sites’ total page weight. The number of image bytes has grown by more than 30% on the average web page in the last year (http://bit.ly/1ttROtq), with very little growth in requests. Thanks to their relatively large file size and the number of images included on the average site (see Figure 3-1), optimizing images is arguably the easiest big win when it comes to improving your site’s page load time.

The HTTPArchive.org () survey of page weight shows that images make up the majority of most sites’ total page weight.
Figure 3-1. The HTTPArchive.org (http://httparchive.org/interesting.php) survey of page weight shows that images make up the majority of most sites’ total page weight.

You can make substantial improvements to both your main content images as well as the images that make up your site design by:

  • Finding the right balance of file size and quality for each image

  • Looking for ways to reduce the total number of image requests on your site

  • Optimizing your site’s image creation workflows for performance improvements

Let’s start by looking at the various image file types available, and then we’ll examine the options you have for optimizing your site’s images for page speed.

Choosing an Image Format

You have a range of file types to choose from when creating images for your site. When generating an image, ask yourself:

  • How compressed can this image be without a noticeable quality reduction?

  • How many colors are needed?

  • Can I simplify this image ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Practical UI Patterns for Design Systems: Fast-Track Interaction Design for a Seamless User Experience

Practical UI Patterns for Design Systems: Fast-Track Interaction Design for a Seamless User Experience

Diana MacDonald
Designing with Data

Designing with Data

Rochelle King, Elizabeth F Churchill, Caitlin Tan
Design It!

Design It!

Michael Keeling

Publisher Resources

ISBN: 9781491903704Errata Page