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Why you should NOT use Flash on your website

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Article by Raphael Champeimont (Almacha).

Why not use Adobe Flash

It is not a web standard

HTML, XHTML, CSS and ECMAScript are web standards. That means that an organization (The W3C for HTML and CSS) has written a specification, which is a document describing the language. For example, the HTML 4.01 specification says that the <h1> tag means "begin of level 1 title". Standards are important because different vendors can implement the same standard. For example, with browsers, if an author writes a website using HTML, the different browsers (like Firefox, Internet Explorer, Safari, Opera...) will be able to display the website because they all implement the HTML specification.

The problem is that Flash is not a standard, it is a language developped by Adobe (Macromedia before), which also writes the program that is necessary to read it. While HTML, CSS and ECMAScript can be read directly by a browser, Flash requires the Adobe Flash Plugin to be installed. If a website uses Flash, you are obliged to install this program (you cannot do like with browsers, choose the program you want).

It requires proprietary software

If you use Flash on your website, you oblige people to install proprietary software on their machines. This is a problem because:

• The Flash plugin is only available for a few architecture/OS combinations (platforms). People using combinations not supported by Adobe simply cannot use Flash. If Flash were free software, other people could modify it to run on more platforms, but this is impossible because the source code of Flash is not plublicely available.
• Adobe can decide to change the Flash technology the way they want, they can for example break compatibility with Flash applications written for previous versions.
• People might not want to use proprietary software on their machines because they support free software (What is free software?, Why use it?).

Use of Flash is discriminatory towards some users

• Users of unsupported platforms (OS/architecture combinations) cannot use it.
• Users of text-based browsers: For example blind users using braille terminals or speech synthesizers cannot read websites that use Flash for the content.

Making a website in Flash goes against the real progress of the Web

Modern Web standards: HTML with CSS

With HTML 4, a new idea was introduced: semantic HTML. HTML 3 was used to describe the meaning of pages, but also their appearence. Starting with HTML 4, authors should now use HTML to specify the meaning of their pages. For example, HTML 4 lets you say "here is a title", "here is a paragraph", "I want to insist on that word", "this is a list" but not "this is writtent is red", "this is italics", "this is written with a big font". For this latter things, a new language was introduced: CSS. CSS lets you say "when I insist on a word, I want it written in red", "titles are written in blinking blue with an orange background", "links are pink and underlined".

This new concept has many advantages:

• You can propose different style sheets for your website. For exemple, a stylesheet called "B&W" could say "title are big, black and bold", while another stylesheet called "colourfull" could say "titles are red with green background and blue border".
• You can write your whole website using HTML that say "here is a title" (but not "this is red"). Then you just need to write a CSS stylesheet that says "titles are red". If you want to change the color, you don't need to edit all HTML pages, you only need to change one line in the CSS file from "color: red" to "color: orange" for example.
• It allows users of text-based browsers to get the meaning of your text. For exemple if you use HTML to say "I want to insist on that word", a visual browser may display it with a bold font, or display it in red (if your CSS stylesheet says "emphasised words are written in red") and a speech synthesizer may speak louder when reading the word.

Going backwards?

Future HTML version, HTML 5, will go further in this "semantic Web" way. But using Flash to write your website goes the other way, the way of everything based on visual appearence, against interoperability and modularity.

Writing a website completely in Flash is bad design

Even for users able to use Flash (using a supported arch and OS, and a visual browser) it can be annoying tu read a website written in Flash for the following reasons:

• It breaks the back button. The user cannot click "back" to go back, because when you browse through a Flash application, you stay on the same page from the point of view of the browser.
• Users cannot change font size in which the page is displayed.
• Users cannot search in the page.
• Search engines cannot index content.
• It uses a lot more resources (CPU) of the client than HTML (even with ECMAScript).

What you should use instead

For content: HTML (or XHTML) and CSS

The best is even to use semantic HTML as desribed above. HTML is a widely implemented standard. A website written in HTML will be readable by anyone, whatever the type of browser (visual, speech synthesizer), the OS (GNU/Linux, Windows, MacOS, OpenBSD...), the architecture (PC, Mac, SPARC, cellphone, PDA...) and the software (Firefox, Safari, Internet Explorer, lynx...). For the visual style you should use CSS.

For interactivity: ECMAScript and CGI

By CGI we mean any sort of server-side programs that generate dynamic content. CGI lets you write programs that give the user a page with content generated dynamically for him. CGI programs can be written in any language (PHP, Perl, Python, Ruby...). For exemple wikis use CGI programs to display content.

ECMAScript (often called JavaScript) is a way to create more direct interactivity, by embedding programs directly in the HTML code using the <script> tag. This is used in what is called "Web 2.0" sites. ECMAScript is already a standard, and its interaction with HTML objects in being specified in the future HTML 5 standard (but it already works!).

For complete applications like games: Java

If you want to write a complete program, you could use a cross-platform language like Java, which allows you to write applets (program embedded in HTML pages). Note that this is completely inappropriate for writing the content of a website (it would have the same problems as Flash). This is more for example to write games playable directly on a website. Java is better that Flash for this because:

• There are several working implementations like the Sun Java VM, SableVM, Kaffe. Flash has other implementations like gnash but they are not yet enough compatible.
• Java is more cross-platform. This is one of the main goals of the language. The official Sun Java Virtual Machine works on most UNIX variants and on Windows, and its source code is available.
• Java is being progressively freed (made free software) by Sun (this is planned for Java 7).

For video: <object> or simply a link to the file

If you want to make a video available you can insert it on a HTML page using the <object> tag. You can also simply make a link to the video file. HTML next version, HTML 5, will provide a new <video> tag to improve video embedding.

$Id: flash.cgi 183 2008-04-01 19:09:50Z almacha $

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