IE9 and JPEG-XR: first impressions

One of the new features in IE9 is the support for the JPEG-XR format, which reportedly has a better compression. Is it something we should dive into ASAP? JPEG-XR The wikipedia article is here. This format is developed and patented (red flag!) by Microsoft (yellow flag! 🙂 ), it replaces the suggested JPEG-2000 format and […]

April 5th, 2010
Tags: IE, images, PEAR, performance, PHP certification

Publishing 5 books this year

So I’ll be publishing 5 books this year. Isn’t that incredible? Is it even possible? And good quality books at that? It’s a nice challenge (my last year’s challenge failed, I didn’t even bother to count how bad it failed). I think it’s possible, especially if you bend a little bit the meaning of “5”, […]

April 1st, 2010
Tags: CSS, JavaScript, News/personal, performance, writing

YUICompressor’s CSSMin

Honored to be a part of the YUI project, I am now helping with the maintenance of the CSSMin part of the YUICompressor. My changes are now part of the trunk on github, so I’m official. Next on the agenda is documenting the thing, so that’s what I’ll try to do here, maybe in a […]

March 10th, 2010
Tags: CSS, JavaScript, performance, tools, yui

Uncompressed data in base64? Probably not

The beauty of experimentation is that failures are just as fun as successes. Warning: this post is about a failure, so you can skip it altogether 🙂 The perf advent calendar was my attempt to flush out a bunch of stuff, tools and experiments I was doing but never had the time to talk about. […]

February 4th, 2010
Tags: CSS, images, performance

One-click Minifier Gadget (OMG) – initial checkin

So I’ve been thinking and talking to folks about this idea of having one-stop shop for all your minification needs. Minification of JS and CSS as well as image optimization helps site performance by reducing download sizes. This is good. But not a lot of people do it. People don’t do it, because it’s a […]

January 31st, 2010
Tags: CSS, images, JavaScript, performance, tools, yui

Performance job offers

I’m sure quite a few of you my fellow readers are crazy about web performance. And if you’re seeking new challenges, timing can’t be any better. Below are three excellent opportunities in three of the most high-traffic sites on the planet. Yahoo! Search is hiring a senior performance engineer. Yep, you’ll be working with me […]

January 28th, 2010
Tags: facebook, performance, yahoo, yui

Feliz Navidad Merry Christmas 2009

Disregarding my dear wife’s opinion that the best present to my blog readers would be to *not* publish my new recording…. I’ll just go ahead and do it: Feliz Navidad ’tis a heavy metal sort of cover of Jose Feliciano’s Feliz Navidad. I hope you like Iron Maiden and Helloween (there’s a special treat between […]

December 25th, 2009
Tags: Fun, Music

The performance business pitch

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 24 This post is the last article in the 2009 performance advent calendar experiment. The idea for this post actually came from the awesome Jeremy Hubert. I met him after a tech talk at Yahoo! I co-delivered and we talked about the presentation. The […]

December 24th, 2009
Tags: performance

CSS performance: UI with fewer images

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 23 This post is the one-before-last article in the 2009 performance advent calendar experiment. Often performance improvements come with their drawbacks, sometimes improving performance causes pains in other parts of the development process or strips stuff from the final product. Sometimes there’s even a […]

December 23rd, 2009
Tags: CSS, images, performance

iPhone caching

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 22 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come – only 2 to go! Some time ago there was a post on YUIBlog highlighting the findings of Wayne Shea and Tenni Theurer on the […]

December 22nd, 2009
Tags: performance

Progressive rendering via multiple flushes

2010 update: Lo, the Web Performance Advent Calendar hath moved 10/2011 update: You can also read the web page with Romanian translation (by Web Geek Science) Dec 21 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. Perceived page loading time is just as important as […]

December 21st, 2009
Tags: HTTP, performance

Extreme JavaScript optimization

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 20 This article is part of the 2009 performance advent calendar experiment. Today’s article is a second contribution from Ara Pehlivanian (here’s the first). There’s a Belorussian translation provided by Patricia. Thanks! Ara Pehlivanian has been working on the Web since 1997. He’s been […]

December 20th, 2009
Tags: JavaScript, performance

The new game show: “Will it reflow?”

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 19 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. Intrigued by Luke Smith’s comment and also Alois Reitbauer’s comment on the previous post about rendering I did some more testing with dynaTrace and SpeedTracer. […]

December 19th, 2009
Tags: CSS, IE, JavaScript, performance

DOM access optimization

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 18 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. This blog series has sailed from the shores of networking, passed down waterfalls and reflows, and arrived in ECMAScriptland. Now, turns out there’s one bridge […]

December 18th, 2009
Tags: JavaScript, performance

Rendering: repaint, reflow/relayout, restyle

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 17 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. UPDATE: Ukraine translation here. Nice 5 “R” words in the title, eh? Let’s talk about rendering – a phase that comes in the Life of […]

December 17th, 2009
Tags: CSS, JavaScript, performance

How To Measure Web Site Performance

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 16 This article is part of the 2009 performance advent calendar. Today’s article is a contribution from Eric Goldsmith. Please welcome Eric and stay tuned for the articles to come. Eric Goldsmith (@GoldsmithEric), Operations Architect at AOL, has more than 20 years of experience […]

December 16th, 2009
Tags: performance

JavaScript loading strategies

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 15 This article is part of the 2009 performance advent calendar experiment. Today’s article is a contribution from Ara Pehlivanian, author of two JavaScript books. Please welcome Ara and stay tuned for the articles to come. Ara Pehlivanian has been working on the Web […]

December 15th, 2009
Tags: JavaScript, performance

Free-falling waterfalls

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 14 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. In this serias of performance posts, so far we’ve looked at having fewer components in the waterfall (meaning less HTTP requests) and also making the […]

December 14th, 2009
Tags: browsers, performance

Give PNG a chance

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 13 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the articles to come. People are often afraid to use PNG because they think that: a/ it doesn’t work in all browsers, or b/ filesizes are bigger than GIF […]

December 13th, 2009
Tags: CSS, images, performance

Big list of image optimization tools

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 12 This post is part of the 2009 performance advent calendar experiment (12 articles down, 12 more to go). Stay tuned for the articles to come. Let’s continue the topic of reducing file sizes started with the previous post and talk about making images […]

December 12th, 2009
Tags: images, performance, tools

Reducing the payload: compression, minification, 204s

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 11 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the next articles. After removing all the extra HTTP requests you possibly can from your waterfall, it’s time to make sure that those that are left are as small […]

December 11th, 2009
Tags: CSS, JavaScript, PEAR, performance, php, tools, yui

Caching vs. inlining

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 10 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the next articles. Looking back at the life of Page 2.0. and all the opportunities for optimization, the posts I’ve put up so far as part of this advent […]

December 10th, 2009
Tags: performance

Duplicates and near-duplicates

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 9 This post is part of the 2009 performance advent calendar experiment. Stay tuned for the next articles. One of Yahoo!’s first batch of performance best practices has always been “Avoid duplicate scripts” (check Steve Souders’ post). Later we added “… and styles”. This […]

December 9th, 2009
Tags: CSS, images, JavaScript, performance

Collecting web data with a faster, free server

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 8 This article is part of the 2009 performance advent calendar experiment. This is also the first ever guest post to this blog. Please welcome the world-famous Christian Heilmann! And stay tuned for the next articles. Chris Heilmann is a self confessed data junkie […]

December 8th, 2009
Tags: api, performance, php, yahoo, ydn

Data URIs, MHTML and IE7/Win7/Vista blues

2010 update: Lo, the Web Performance Advent Calendar hath moved Dec 7 This is the seventh in the series of performance articles as part of my 2009 performance advent calendar experiment. Stay tuned for the next articles. UPDATE: While this post is an interesting study, the problem it solves turns out to be much simpler. […]

December 7th, 2009
Tags: CSS, IE, images, performance, php