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Rocky outcrop at sunset, Approx 27°56'15"S 119°38'17"E




It should be obvious that my preferred browser is Opera. Not that there's anything wrong (much) with Firefox/Thunderbird/Mozilla. I just prefer using an internet suite. The best suite (in my opinion) is Opera. The Mozilla suite is just too big, fat, and ugly.

This section of my site is dedicated to anything I have to say about Firefox, Thunderbird and other Mozilla projects.

Opera Skin for Firefox

Do you use Firefox for testing? Don't like the skin? Prefer Opera's? See: http://www.imsuden.f2s.com/firefox/opera7skin/!

Extensions to get Opera-like Functionality

This is a work in progress. Note that all the following are at least an extra 1724KB to download.

Mozilla Update

Extensions Mirror

Other Links

Opera vs Firefox and Thunderbird


A frequent dig by Firefox fans at Opera is that Opera is "bloated". Usually what is meant by that is that the default user interface is more complicated relative to Firefox. In the past this was true, but the latest version of Opera is much more streamlined in that area, so I thought it worthy of a test.

"Bloat" could also refer to higher resource requirements (memory, CPU, hard drive), given that Opera has so many more features built-in compared to Firefox. So I wanted to investigate that, too.

Test Environment

Test machine was a VMware 4.5.2 virtual machine running a clean installation of Windows 2000 (SP3) in 192MB of memory and video set to 1024×768 and 32-bit colour. Host machine is a 1GHz Athlon, 512MB memory, nVidia GeForce 4 440MX video card, Windows 2000 SP3. Tests were conducted on 20th April 2005.

Browser Comparison

Opera 8.0Firefox 1.0.3
Installed space
(does not include user profiles)
User Interface10 buttons8 buttons
2 fields2 fields
6 top-level menu items7 top-level menu items
48 second-level menu items52 second level menu items
Page Display Area
(res:1024×768, scrollbar included)
1018×608 (79%)11024×613 (80%)2
Startup Memory Requirements14MB17MB
Startup CPU Time7sec6sec
Load 20 Sites370MB66MB
CPU Time to Load 20 Sites41:300:54
Close 20 Pages49MB47MB
Minimise, wait9MB3MB
Restore, wait11MB8MB
JavaScript Benchmark514.8229.02
  1. The most space efficient Opera ads were selected - the Google relevant text ads. The graphical ads would reduce the available space by 30 pixels of vertical space (to 1018×576 (75%)) and reveal the main toolbar, adding 9 buttons. Registration of Opera removes the ads, increasing available page display space to 1018×636 (82%).
  2. By default, Firefox does not show the tab bar. That would add one extra button, and subtract 29 pixels of vertical space (to 1024×584 (76%)).
  3. ABC News, BBC News, Yahoo News, Amazon, Arstechnica, Barnes and Noble, CBC Canada, Sports Illustrated, Expedia, The Motley Fool, Fox Sports, FreeBSD, How Stuff Works, LawMeme, New York Post, New York Stock Exchange, New York Times, National Post, Slashdot, ebay (all those saved as an Opera bookmarks file: bookmarks.adr)
  4. Approximate times. 1536/256kbps ADSL link. The above 20 sites were bookmarked into a folder and the "open all folder items" option selected. The start page for each browser was set to "about:blank", Java was disabled, popups blocked, caches were cleared. The Windows Task Manager was running "always on top". Of note was that after loading all the pages, Opera averaged a 30% CPU load and Firefox about 10%, presumably to handle image animation, background JavaScript, etc.
  5. Each browser was tested five times, the best and worst results discarded, the average (arithmetic mean) of the remaining three tests is the final result. Popup blocking was disabled. The raw results were: Opera (13.64, 14.80, 14.86, 14.97, 14.80), Firefox (29.44, 26.78, 28.44, 29.39, 29.22).

Email Client Comparison

To do this, I exported my "live" Opera mail Received folder (3504 messages) into a single 54.1MB MBS file. These messages were then each imported into a fresh install of Opera and Thunderbird. Since Thunderbird doesn't support importing plain MBOX files, I followed these instructions to copy the MBOX file directly into a new folder file.

Opera 8.0Thunderbird 1.0.2
Installed space
(does not include user profiles)
Installed space
(user profiles only, after import)
User Interface13 buttons110 buttons
1 field2 fields
7 top-level menu items7 top-level menu items
56 second-level menu items67 second level menu items
Startup Memory Requirements216MB18MB
Startup CPU Time5sec35sec
Minimise, wait1MB2MB
Restore, wait3MB7MB
  1. Includes the "New page" and "Closed page" buttons, which are really only applicable to web browsing, not doing emails.
  2. Includes selecting the "Received" folder in Opera, and the "Imported" folder in Thunderbird.
  3. Opera's time here is much quicker than the browser time because a blank page was selected as the starting page, whereas the browser time includes loading and rendering the default startup web page. If Opera was being used only as a mail client (like Thunderbird is only a mail client), then loading a web page doesn't seem likely.

Combined Browser+Email

Opera 8.0Firefox 1.0.3 + Thunderbird 1.0.2
Installed space
(does not include user profiles)
Installed space
(user profiles only, after import)
User Interface20 buttons18 buttons
3 fields4 fields
7 top-level menu items14 top-level menu items
56 second-level menu items119 second level menu items
Startup Memory Requirements16MB133MB
Startup CPU Time7sec7sec
  1. Includes the startup page, and opening a Mail window to view the Received folder.


Download and Storage Requirements

Opera is a smaller download, definitely still important for the many people still on dialup. Particularly when browsers are regularly updated.

Once installed, Opera uses 9MB less space than Firefox. If all you consider is the size of your hard drive, that doesn't sound like much, however, many people install a browser onto their USB thumb drive (~128MB) or onto a mini-CD (~50MB). In those situations, every MB counts, and Opera delivers.

For email storage, Opera requires about 15% more space than Thunderbird, presumably for the indexing used for the lightning-fast text searches.

Memory Requirements

Opera requires a little more memory than that required by Firefox to surf the 'net. Firefox releases much more when minimised, which has resulted in some complaints that Firefox takes too long, sometimes over a minute, to "wake up" when restored. Restoration seems to be a mixed bag with a variety of results.

CPU Requirements

Firefox was much faster than Opera when loading the 20 test sites. This was the only significant difference between this and my earlier tests last year. In those tests Firefox was similar to Opera.

Since this was such a big change, I looked a little closer using Ethereal:

Between first and last packet131.714 sec66.090 sec
Avg. packets/sec124.064166.698
Avg. packet size395.872 bytes575.514 bytes
Avg. bytes/sec49113.59895936.788
Avg. Mbit/sec0.3930.767
Throughput (black=Opera, red=Firefox)

It looks like Firefox is able to better utilize the available bandwidth, with a fairly constant fast transfer, while Opera was not only less consistent, but slower as well.

Update: I've been contacted by some other Opera users who have been unable to replicate my thoughput issues. Their experiences were that Opera and Firefox were basically the same. I'm investigating. Possibilities are that my internet connection is through a Linux box acting as a firewall and that I'm using a virtual machine and that those could be doing strange things. However, I would have thought that those things would influence Opera and Firefox equally.

Another issue that clouds the speed issue is the fact that many web sites do not compress their data for Opera, but do for IE and Firefox, in spite of the fact that Opera is just as capable of handling it. Google, Amazon and Yahoo are three popular sites that have this issue (see also this Opera Forums thread). It's unlikely to be deliberate, more a white-list of browsers that support compression, as opposed to a black-list of browsers that don't. However, the end result is that due to the lack of compression, Opera is forced to download a lot more data compared to IE and Firefox, which naturally enough, makes things slower.

User Interface

Opera Software have significantly improved the default user interface from their previous versions. The starting state of both browsers is now comparable. In terms of display area, Firefox squeezes in a few extra pixels.


Opera does not display any evidence of "bloat" of any sort. Apart from the throughput issues (which may be just my setup), it appears to be smaller, lighter, and as fast (if not faster) in all respects.

A Brief Try of Thunderbird

I thought I'd just give Thunderbird (v1.0 final) a quick try, but I couldn't be bothered actually using it as my email client - I have no intention of giving up Opera Mail - and trying to manage the same email using two clients is just asking for trouble.

The answer was to try out its RSS newsfeed functionality.

The installation was painless. "Don't import anything". Next. "RSS News & Blogs". Sounds good. I then right-clicked on "News & Blogs", selected "Manage Subscriptions" and then the "Add" button. I filled in my website newsfeed address and clicked OK. I was informed TB was downloading 15 articles.

Bug #1: only nine showed up! Not a good start. One bug already less than a minute into the trial. And they weren't the most recent nine of the fifteen either. It got the first three, skipped one, got the next four, skipped one, got the next one, skipped two, got the next one, skipped the remaining two.

Yes, the feed does validate, thank-you-very-much.

Whatever. I clicked on an item. The relevant web page appeared in the mail view! That wasn't what I expected. In hindsight, I realize now that I missed the "Show article summary" checkbox, but I expected TBs reader to work like Operas. Still, it should be simple to change the configuration, no? Manage subscriptions, edit the subscription, tick the box. Done.

Bug #2: nothing changed! It was still loading up the web pages. Perhaps I need to restart TB "for the changes to take effect". Not that either. OK. Delete subscription, change the default to "Show article summary" and resubscribe. "Downloading 15 articles...".

Bug #3: only one article now appeared! Where are the others?!

Test over. Three bugs in under five minutes is not good. I think I'll wait for version 2...


Ah yes, bloat. The classic anti-Opera excuse used by Mozilla fans. Comprehensively disproved earlier on this page, my Thunderbird test made it clear to me that "bloat" can appear anywhere.

How about placing virtually an entire web browser in an email client? Implementing HTTP, HTML, XML, CSS, RSS, JavaScript, and DOM support, we have ... not Firefox, but Thunderbird!

Let's face it: these days an email client that can't handle at least showing HTML emails is pretty poor. (Composing and sending of such is an entirely different debate!) That means putting in an entire web browser.

For any email client to be taken seriously, they have to be a superset of a web browser. If you have to build a web browser into your email client, it doesn't make much sense to have a standalone browser anymore, does it? For just a little extra chrome, the email client can be a web browser!

Having your standalone Firefox web browser, then duplicating upwards of 95% of that functionality in Thunderbird, well that's what I'd call bloat!