Differences Between Various Browsers

The following is only a partial index.

HTML Differences - <li> | Headings | Greek Letters | Text Files | Style Sheets
Table Differences | Printing | AOL
User Interface Differences - Refresh/Reload | Viewing Source | Viewing a Link's URL | Frames

For links to download current browsers, see The Web Standards Project.

HTML Differences

<a href=http:fonts.htm>font</a> 	Works in Netscape, fails in IE3
<a href=fonts.htm>font</a>   		Works in both Netscape and IE3

&lta href=fonts.htm>font&lt/a>          Shows < in IE3, &lta in Netscape
&lt;a href=fonts.htm>font&lt;/a>        Shows < in both (notice the semi-colon)

<a href=a:fonts.htm>font</a> 		Works in IE3, fails in Communicator 4.05
<a href="A|/fonts.htm">font</a>         Works in IE3, fails in Communicator
<a href=file://a:fonts.htm>font</a>   	Works in both Communicator and IE3
<a href="file:///A|/fonts.htm">font</a>	Works in both Communicator and IE3
<a href="file://A|/fonts.htm">font</a>	Works in both Communicator and IE3
<a href="..\fonts.htm">font</a>	        Works in IE4.72, fails in Communicator 4.05
                                          if file on unix, works if local
<a href="../fonts.htm">font</a>	        Works in both Communicator and IE4
<%begindetail%>                         Display in Netscape Communicator 4.05
   and other <% .. %> htx tags            but not in IE 4.0
<a title="popup text">link</a>	        Text pops up in IE4.72, 
                                           not in Communicator 4.05
<textarea>..</textarea>                 This wraps in IE 4.72 
                                           but not Netscape 4.05
                                           Details and fix

Netscape Communicator 4.01a has a problem with <p>. It appears that </p> is required in various situations, particularly inside tables. This is particularly true when the table is inside a <div> block which is hidden via style sheets, though I've seen it both ways. (According to the standards, </p> is never required.)
<code> does not work as expected. Whitespace is completely ignored by IE 3.02, Communicator 4.05

I expected all whitespace to be preserved (including tabs and carriage returns) and all HTML tags to be ignored. Of course, the HTML Spec says nothing about what the tag is actually supposed to do. It just one of those Browser dependent things.


I have heard that (ie not seen myself that) Netscape 6.2.1 has problems with the <br> tag in a definition list - <dl> ... </dl>. Netscape 4.78, IE 6, and Opera 6 are reported as ok.


Most browsers treat <li> tags which are not in a list structure as breaks and place bullets in front of the text. The following is an example:
  • IE 3.02 - Provides bullets which are the same size in both cases
  • Communicator 4.05 - The bullets outside a defined list are much smaller.
  • With IE 4.72 SP1 - Provides bullets which are the same size in both cases but the text wraps back to line up under the bullet.
  • IE 4.40 ignores <li> tags unless they are in a defined list


    Heading tags may contain alignment parameters. The align=right option is supported by Netscape 3.x, Communicator 4.05, IE 3.02, and IE 4.72 SP1 but not IE 4.40.

    <h2 align=right>...</h2>

    Horizontal Rule

    In IE 5, to set the color of the Horizontal Rule, simply use <hr color=red>
    This does not work in Netscape 4.05 or 4.75.

    Greek Letters

    IE 5 has added support for Greek letters. Just type in the name of a letter with the standard delimiters. Both upper and lower cases are supported. Upper case - &Alpha; &Beta; &Gamma; &Delta; ... &Pi; &Phi; &Theta; &Omega; Lower case - &alpha; &beta; &gamma; &delta; ... &pi; &phi; &theta; &omega;

    IE 4.72 shows boxes
    Netscape 4.05 shows the tag values.

    Text Files

    Normally, browsers display the contents of text files (files ending with .txt instead of .html) without interpreting any of the codes. For instance, when my Raw Notes text file was read from a local drive, IE 4.72 & IE 5.00 displayed it as a simple text file. However, when either of these browsers read it from the web (same file and same extension), the html tags were interpreted and the file was displayed wrong! This was checked using 2 different versions of IE on 2 different machines. What I found is unbelievable (well Microsoft is involved) - the way the file is treated is controlled by how many characters there are from the beginning of the document and the first <pre> tag. No kidding. If the <pre> is more than 188 characters from the beginning of the file, it is treated as a text file, otherwise, it is treated as an html file. (188 is a rough estimate since I didn't count 3 CR/LF pairs.) <pre> is the only tag that seems to matter.

    Well, today IE 5.0 interpreted a txt file containing <html> or <head> or <title> or <body> in the first few lines. (It was a perl cgi script re-named as a text file so that users could view the code.) Uh, notice I said or, any one of these causes the problem. Also, <br> has no effect.

    Demo file showing the <pre> failure in IE only.

    Netscape Communicator 4.05 always displays it as a text file.

    Style Sheets

    There are almost an infinite number of Style Sheet differences.

    Table Differences

    When using tables, the value of cellpadding affects what is displayed. However, the value has little effect when printing from IE 3.02. When lines are displayed, cellpadding=4 prints well with Communicator 4.05. When lines are displayed, IE 3.02 prints with the text touching the lines.
    When using tables, bgcolor="#00ffff is supported by IE 3.02 and Netscape Communicator 4.05, but not by Netscape 3.x. In addition, Communicator 4.05 prints gray if the background color is set. The others only print white.
    When using tables, if the table tag contains either an absolute or a relative width, and the td tag contains an absolute width, then Netscape Communicator 4.05 ignores the td width but IE 4.72 handles it as expected. Netscape Communicator 4.05 works correctly when both widths are relative.
    When using style sheets and tables, IE 3.02 ignores <font color=red> tags, while IE 4.40, IE 4.72 and Communicator 4.05 interpret them as expected. Example.
    IE 4.40 incorrectly handles a <br> in tables. In this example, it placed the line after Test case 2 <br> in column 1 instead of column 5.

    This is fixed in IE 4.72 SP1.

    The BORDERCOLOR="red" attribute (generated by MS Word 97 and not part of the html specs) has various implementations. (Actually, Word generates BORDERCOLOR="#ff0000".)
    IE 4.40.308 should never be used. Ever.

    This table formats in a single column in IE 4.40, but in 4 columns in other browsers, including IE 4.72

    IE 4.40.308 only allows one instance (window) to be opened. All the other Windows browsers allow you to open as many windows as you like.

    Printing Differences

    The following table prints differently in IE 4.72 and Netscape Communicator 4.05
    <tr><td align=right>    93 <td> /user/clemenzi/technical/
    <tr><td align=right>    165 <td> /user/clemenzi/technical/HTML_Examples
    93 /user/clemenzi/technical/
    165 /user/clemenzi/technical/HTML_Examples
    The displays are nearly identical, same proportional font, same line width, same alignment of numbers. However, they print differently.

    AOL Differences

    AOL access is not the same as Internet access. Pages are formatted differently, java scripts fail, and image quality is significantly reduced. AOL intentionally modifies their browsers in order to make them more incompatible than necessary. In addition, the AOL server modifies web content, especially images, before forwarding it to its users. In order to test your site on the current AOL browsers, you will need one computer per browser version (assume at least 3 versions) and an AOL account :(

    For more information, see AOL Design Information.


    AOL 6 & 7 both have the ability to display html email. webmaster.info.aol.com explains why html email is sometimes displayed as text and indicates which html tags are ignored (mostly do to security issues).

    Format HTML Email for AOL provides some additional data.

    My Email Clients page provides some additional data.

    WARNING: AOL 5.0: The Upgrade of Death?

    User Interface Differences

    Netscape Communicator 4.05 and IE 3.02 do not share the same cookies.


    Refresh/Reload works differently When I'm debugging a new page, its nice to reload without having to scroll to see the change I just made.

    I always work in notepad because ALL the other tools I have tried have done something or another that irritates me. When using IE, Alt F S Alt-Tab F5 switches from notepad to the browser, and Alt-Tab switches back. (so far, IE 4.72 is the best for this, IE 3.02 loses your position, Netscape does not have a simple reload hot key.)

    Viewing Source

    View Source works differently - IE 3.02, IE 4.40, IE 4.72, and Netscape 3.x all display the source in notepad. However, when developing a site locally, IE 3.02 and IE 4.72 save the file in the correct directory on the local drive, while IE 4.40 and Netscape 3.x save your changes in the browser's cache directory. Thus, when you simply save, it goes to the wrong place.

    In addition, though Netscape 3.x displays the page ok, once it is saved, all of the white space and carriage returns are removed.

    Communicator 4.05 has its own browse and edit programs.

    IE 3.02
    • Only the last 5 items in your history list are available via the Go menu.
    • Right clicking the page does not provide a Back option.
    IE 4.72 SP1
    • Right clicking the back button displays your history list. This data is no longer available via the Go menu.
    • Right clicking the page provides a Back option.
    • Your history list is available via the View menu.
    • Right clicking the page provides a Back option.

    Viewing a Link's URL

    When you point to a link, sometimes there isn't enough space to see it
    Netscape 3.xVery good
    Netscape Communicator 4.05Almost enough, so so
    IE 3.02Very good - the best possible - the entire lower status bar
    IE 4.40Totally worthless - about 20 characters
    IE 4.72Totally worthless - about 20 characters
    IE 5.00Pretty good - about 70 characters
    Supposedly, IE 4.01 SP2 fixefss this problem. (Since I don't have it, I can't test this.) You can also try the following add-ons
    IE 4.72 does not allow you to configure a non-Microsoft email client as the default when you click a mailto link. This is totally unacceptable.


    Both IE 4.72 and Netscape 4.05 allow you to right click in a frame and select Open Frame in New Window.

    IE 5.00.2314.1003 has removed this option. Based on this single fault, I recommend never loading IE 5! This is a perfect example of MS in action - every new product removes a very useful feature.

    Javascript and Metatag fixes to this problem will allow you develop pages which can not be trapped in some pirate's frame.

    Author: Robert Clemenzi - clemenzi@cpcug.org
    URL: http:// cpcug.org / user / clemenzi / technical / HTML_Examples / Differences.htm