Can be programmed with a statically-typed .net language like
C#, which is compiled and a lot of errors can be caught at compile time.
functionality, which is not compiled and errors are prone, requiring
extensive testing. Also requires extensive CSS/CSS3 knowledge and usage.
Silverlight is a plugin works the same in IE and all other
HTML5 is a work in progress, the standards body scheduled to
complete specs in 2022, could work differently in different browsers. Also it
might require using the DOM elements supported by the different browsers.
Requires understanding of the browser sensibilities to the DOM elements,
since all browsers are not standards compliant, especially IE.
UPDATE on 02/14/2011: HTML5 Spec to be completed in 2014, check this updated
With newer versions of Silverlight released, newer browser
versions should support the older versions of silverlight. If we build in
Silverlight 4.0 and the application is running fine. If a newer version of a
browser is released which will not support Silverlight 4.0( instead it
supports a newer version of Silverlight), we may have to stop the users from
upgrading to a newer version of browser.
HTML5 as it is now, is not supported in older versions of the
browser like IE6 and IE7. HTML5 is also evolving and newer browser versions
will have better support for HTML5, but it may work differently in different
browsers, since there is no defined HTML5 standard as yet and it is a work in
progress. But for the most part, HTML5 once built should work in newer
versions of the browser.
Silverlight requires a plugin required to be installed in the
browser, as of now it is not bundled into the browser. Some systems might not
allow to install plugins.
HTML5 is built into the newer versions of the browser, no
Easier to program complex and rich functionality with a known
language like C#
jQuery which provide rich functionality but not equivalent to Silverlight.
Silverlight video plays as long as the silverlight plugin is
installed in the broswer. Will not work on Apple devices like iPad and
Depending on the encoding, if the video is encoded in H.264,
HTML5 will play the video in IE and Safari without installing any additional
plugin. Also works on Apple devices like iPad and iPhone. Firefox, Chrome and
Opera support Theora or Vorbis encoding, with support for WebM soon. Requires
the video to be encoded in more than one codec to support all browsers.
Silverlight on smartphones is a disadvantage since it is
resource hungry and not supported on all platforms.
HTML5 is lightweight comparatively since it is built into the
browser and it does not take up as much resources.
Silverlight application performance will be better since it is
already parsed and compiled into bytecode form.
engines in the newer browsers, but since it is dynamically typed language it
might not be the same as the statically-typed and compiled silverlight.
Intellectual Property Protection is better with Silverlight,
since it is not easy to reverse engineer a silverlight application.
competitors can easily view the source.
Webkit layout engine based smartphone browsers like Safari,
Chrome and Opera do not support Silverlight. Webkit is evolving fast as the
mobile browser standard.
machine code, eliminating the need for a bytecode interpreter and thus
Client side local storage using IsolatedStorage, upto 1MB, can
be increased with permissions. Need to store in files and read from files.
Data stored in the local storage can be encrypted for security.
HTML5 supports SQLLite, a lightweight client side database,
can be saved and retrived as queries. Can store upto 5MB, not supported on
all browsers. Currently only Safari, Chrome and Opera. Not supported in IE
yet. Local storage data cannot be encrypted like Silverlight storage.
Silverlight can access the Webcam/Microphone on the users
desktop, providing richer media experiences.
HTML5 does not support access to the WebCam/Microphone as of
Silverlight videos content can be protected through DRM(
Digital Rights Management).
HTML5 videos do not support DRM
Silverlight supports adaptive smooth streaming, Silverlight
videos are encoded into 3 definitions, depending on the bandwidth
availability, it will stream the appropriate quality, like the highest
quality for the most bandwidth and the lowest quality for the least
No such support in HTML5
Silverlight media supports Information Overlay/Picture in
Not supported by default.
Great Stereoscopic 3D video support out of the box.
Supports 3D, but not as good as Silverlight.
Ability to broadcast live( video/audio) or streaming.
Not supported at this time.
Comes with a full set of 60+ pre-built controls with
customizable styles, also with several third party enhanced control libraries
the functionality of advanced Silverlight controls, requires a lot of
Powerful data visualization through charting controls and
Plugins and libraries are available, but are not as rich as
the Silverlight controls.
Flexible data support including databinding, binary XML, LINQ
and local storage.
There is no 2-way databinding support, as well as support for
LINQ. HTML5 does support 2 flavors of local storage including SQLLite.
Provides Multicasting support, but it works on the UDP
protocol, which has a limitation since it is blocked by most common
firewalls. Also packet security needs to be built by the user since the
packet delivered cannot be guaranteed to be the same as the packet sent. But
great for interactive web applications.
No multicasting support yet.
Responsive UI with .net and Multithreading.
Can provide somewhat seamless experience through AJAX, but may
not be the same as Silverlight.
Conflicting recent views from Microsoft about the future of
Silverlight, creating some doubts in the minds of developers. Some confusion
about MS going to keep improving on Silverlight or put more efforts into
better HTM5 standards support.
HTML5 is evolving, so no way to know if there are going to be
a lot of changes or even if it requires tweaking code with future versions.
Silverlight works on most browsers and versions.
HTML5 is partially supported in Safari, Chrome and Firefox. IE
still does not support HTML5
Newer desktops, laptops, smartphones and tablets are coming
with 2 or more processor cores. Silverlight on .net framework is capable of
scaling upto 8 processor cores.
the future, but not right now.
Silverlight provides rich functionality out of the box or
third party control libraries, easy to upgrade an existing application with
newer versions of the controls, since most controls are built with backward
compatibility, can be upgraded easily by just referencing newer dlls.
To get all the functionality of the Silverlight controls, need
fully tested, so need to upgrade several code sources to keep up with the
upgrades. Also all upgrades might not have proper backward compatibility.
Silverlight can be written once and deployed to the
web/desktop. ( Unfortunately cannot be deployed on Windows Phone 7 since it
uses a different set of lightweight controls)
HTML5 is a markup language for the web. It needs a web browser
to render itself.
Silverlight multi-touch support can take advantage of the
next-generation hardware natively.
Depends on the multi-touch support of the browser.
Silverlight can offload media rendering to the GPU for
Hardware Acceleration. More than one control which supports Hardware
Acceleration, 3D and Pixel shaders.
No Hardware Acceleration support as of yet. Plans to support
it in the future using WebGL technology for the HTML Canvas. WebGL will bring
Hardware Acceleration, 3D and pixel shaders.
Current web is built on the request/response architecture. A
user makes a request for a page to the server, the server sends back the page
to the client. After that the page remains static. With Silverlight, if there
is a change in the content in the server, it can be easily reflected in the
client with the Publisher/Subscriber architecture using net.tcp or WCF duplex
requires lot more coding and also performance is slower.
Faster development with better IDE, tools and controls. Also
use existing developer language strengths.
Silverlight content is not indexed by the Search Engines, not
good for Search Engine Optimization.
HTML is Search Engine friendly, with HTML5 more semantic
capabilities are being added for providing better content to the Search