SlideShare ditches Flash, rebuilds entire site in HTML5


SlideShare, the website for sharing PowerPoint presentations and other documents, has had a major makeover. The company has ditched Adobe Flash (s adbe) technology entirely, and rebuilt its website using the HTML5 markup language, SlideShare co-founder and CTO Jon Boutelle will announce at GigaOM’s Mobilize conference Tuesday.

This means that SlideShare is now viewable on every kind of mobile device, from iPads to iPhones to Android devices and beyond. Another perk is that the website is now 30 percent faster and its files take up 40 percent less space than they used to. Search engines can now read the content within SlideShare slides, meaning that presentations hosted there should start to get much higher page rankings on sites like Google. Text within documents can now be copied and pasted, as well.

The web as “the biggest app store of all”

SlideShare initially set out to build its mobile experience by making individual apps for the Apple store, the Android (s GOOG) marketplace, and others, but quickly realized that in the long term such a strategy would not be sustainable. “If we committed to app stores in general, it would really end up fragmenting our engineering team and our engineering efforts,” Boutelle said in an interview Monday. “We were trying to find an alternative, and the answer is that HTML5 can work on all of these devices. Now the way we frame our thinking is that the web is the biggest app store of all.”

Screenshot of SlideShare's homepage on the iPad (click to enlarge)

Starting Tuesday, SlideShare’s site will be displayed in HTML5 on both desktop and mobile devices, and all new documents added to the site will be rendered in HTML5. Over the next several weeks, the company will be porting its entire back catalog of five years’ worth of presentations to HTML5. SlideShare expects the conversion to finish by year’s end, Boutelle said.

A huge engineering project

Making the big switch has not been easy. SlideShare has 50 employees, the majority of whom are engineers, and all hands were on deck over the past six months to work on converting the site from Flash to HTML5. “This is the hardest thing we’ve ever done,” Boutelle said. But that difficulty should not be apparent to the average SlideShare user (the site receives 60 million unique visitors per month.) “The change is so structural that if we’ve done it right, people will just know that SlideShare is better, but they won’t know why.”

SlideShare is certainly not alone in doubling down on HTML5. Facebook’s new Timeline interface relies heavily on HTML5, and the company’s CTO Bret Taylor has said that the markup language will be a huge part of the company’s development efforts going forward. Apple (s AAPL) has been one of HTML5’s biggest proponents, as has Google. But it’s shaping up to be even more interesting to watch how smaller companies like SlideShare adopt the platform for their own products.


kenny higgins

The web as “the biggest app store of all”

Doesn’t this create a massive problem for Apple, I mean this is the main reason why they banned Flash in the first place?

David Balažic

I use Firefox 7.0.1 and the main page and also many slides still require Flash. Did I misunderstand something?
Or are they migrating slide by slide to HTML5?

John Drinkwater

Sorry, this is dribble. All the major browsers now support HTML5 to some extent: HTML5 parse algorithm, support for a chunk of the newer form and sectioning tags, css animation, etc.

There is only one large compatibility issue and that centres around codecs used in the media tags. Not something that should dissuade anyone from using HTML5; just encode into webm and ogg theora and dont worry about it.

Henk de Vries

* It’s only HTML5 with an iDevice user-agent
* Even then it’s only HTML5 by doctype (not even header/content/footer)
* It doesn’t work in Firefox
* The URLs aren’t the same (you get an entirely different site depending on the UA)

If “This is the hardest thing [you]’ve ever done”, it’s time to get a better development team.

Mike G - Lime Rocket

For their use case I would have to agree the choice of HTML5 was the right one. The decision not to support the AppStore & Market will hurt them in the short term though and they have missed several cross-platform solutions that would have both allowed them to focus on HTML5 and deliver apps to each platform.

Ketan Majmudar

I think its a bout time. I actually stopped using SlideShare as having a SlideShare page open in my browser would burn my battery to a cinder, I reluctantly stopped posting my slides and using the embed features due the use of flash.

This will actually revive my interest and use of the site, good work. perhaps it will also send another message out to browser vendors that they should be supporting HTML5.


Congrads to the slideshare team! Looks like they were able to solve several technical challenges to accomplish this. The end result (HTML+CS+JS) is quite impressive!

Andrew Hunt

Confused about this, what about all the IE6, 7 and 8 users that have no capacity to render HTML5? What are these many unfortunates going to see?

Colleen Taylor

Hi Andrew, good question. The company says that some older versions of browsers will still see a flash version of SlideShare. But the default for everyone else will be an HTML5 site.


Ditches flash but still show flash for half of the visitors? I dont think most of people understand this. Doing slideshows in 2011 isnt the most advanced multimedia you can do.

Kyle Lacy

This is huge! I love that they switched over. It means that I am going to be spending more time on the site in order to maximize the search.


That’s very good news. At long last, programming web sites and applications can be done solely on open standards _and_ web companies get it. This is also one sign of the “rise of JS” and the success of Node.js is great. At the same time, this will allow new high-level web languages like

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