Facilitating the Spread of Knowledge and Innovation in Professional Software Development

Write for InfoQ


Choose your language

InfoQ Homepage News SlideShare migrates from Flash to HTML5

SlideShare migrates from Flash to HTML5

This item in japanese


Today, Slideshare, the popular on-line presentation hosting site, completed its transition to using HTML5 instead of Flash for its eponymous slide sharing utlity.

Previously, browsers had to have Adobe Flash installed in order to view presentations on their site. However, with the advance of HTML5, and an increasing amount of traffic from (mobile) browsers without Flash support, the transition to HTML5 meant that SlideShare could be ahead of the competitors in terms of the delivery of components for other browsers.

Not only that, but the slides load 30% faster, and works in exactly the same way on both desktop computers as well as mobile devices such as the iPhone and iPad. A presentation, naturally in HTML5, explains more:

According to the engineering blog, there were a number of challenges in making this happen:

  • Font conversion: if the browser doesn't support a particular font in the slideshow, it needs to be rasterised on the server and then downloaded to the browser as images.
  • Text placement: to place text in exactly the same place involves figuring out where the PDF says it should be, and translating that to the position in the browser. Given the way that both systems handle font locations, getting text to appear in the right place was not an easily implementation.
  • Cloud infrastructure: Since slideshare runs on Amazon EC2, instead of having each layer of a service hosted by different machines (potentially with latency for between-machine requests) they co-sited every service on every node, something they refer to as the Netflix "Rambo" architecture.

The blog notes that existing slides are being upgraded to HTML5 in the background, and that any new presentations uploaded will be converted to HTML5 by default. However, they note that this new architecture opens the possibility for interactive presentations (such as audio and video) which wasn't possible before.

Rate this Article


Hello stranger!

You need to Register an InfoQ account or or login to post comments. But there's so much more behind being registered.

Get the most out of the InfoQ experience.

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Community comments

  • About easy copy paste

    by Patrick Huizinga,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    It's quite ironic how hard it is to copy all three lines of text from slide 12; the slide that tells you about easier copy & paste.

    Yes I figured out how I can copy all three lines at once, but my mother wouldn't. Plus, I generally care about the order of the lines I copy.

  • What about full screen feature?

    by Ganesh Gembali,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    Good to see new slideshare :).
    But one thing is now it is not straightforward to use full-screen feature as I have to use browser's full-screen feature to make the slides to take complete screen.

  • translations

    by Michael Hunger,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    It would be interesting to see if chrome translations would work on the slides.


Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p