It is a common myth, largely spread by Opera fanbois that Opera invented tabbed browsing. This is very simply, wrong. The first browser that can be said to have tabbed browsing was an Internet Explorer shell called NetCaptor, first released in 1997.
Out of the main browsers it is actually Firefox that can be credited with being the browser to mainstream tabbed browsing. Phoenix (what would later become Firefox) introduced tabbed browsing in September 2002.
Some people consider Opera to have been the first main browser to introduce tabbed browsing because of the inclusion of a Multiple Document Interface. This is incorrect and the difference is not trivial. An MDI is the interface Word 97 had for example. It allows many windows in one, but is not the same as a Tabbed Document Interface. A TDI allows for repositioning tabs on a tab bar, dragging and dropping between windows, open in new tab, easy switching between tabs without having to minimize etc. Fanbois will often cite Opera’s own version history as proof that they were the first browser to include tabbed browsing, however just because opera considered an MDI to be a TDI does not make it so.
When Phoenix 0.1 was introduced it had tabbed browsing support and if you use it today it will still feel quite familiar. Opera on the other hand still only had an MDI at version 6.10>, which was released October 31st, 2002. Opera did not get proper tab support until version 7 which was released January 28th, 2003 although the beta which included the same tab support was released November 13th 2002.
I hope that I have helped to clear this up and denounce this ridiculous myth. Anyone is welcome to see for themselves and download the older versions of browsers and they themselves can confirm that it wasn’t until version 7 that Opera can said to have gotten proper tab support.
All that is wrong with the world... 
Your reasoning is based on dictionary definitions. Put it how-ever you want, Opera was the first browser having ‘fake tabs’.
Comment by analog_ — June 15, 2011 @ 12:17 pm
Opera had multiple windows first, it came to the tab party very late. It isn’t just a semantic difference, an MDI has a lot less functionality than a tabbed interface.
Comment by allthatiswrong — June 23, 2011 @ 2:42 am
A multiple document interface has more functionality, its like a desktop within the window. You can have everything maximized and it’s effectively a tabbed interface, or you can take advantage of extra features in mdi, like having windows sized and placed differently on the screen whilst still being able to tab between them.
Comment by nobody — February 27, 2013 @ 5:44 pm
What I meant was that an MDI as it existed, did not allow for tabs being moved between windows, undo close tab, all of those tab features. Yes, they could be implemented into an MDI…but that hasn’t happened yet. SO an MDI vs a Tabbed Interface loses, sorry to say.
Comment by allthatiswrong — March 3, 2013 @ 5:01 pm
What you are smoking man? 🙂
Since when rearranging, detaching and reopening of closed tabs are mandatory to be called TDI? These are extra features, for many (including me) must have for a useful browser, but not mandated at all (also, this concept is not exclusive to browsers).
And if we are talking about classic Opera (RIP) then they had mixed MDI and TDI, and IMHO this is best way to get most flexible solution for power users (and not only for browsers) since you can (and should, by default, as Opera did) use MDI as TDI only by adding simple tab bar and maximizing MDI windows.
Comment by Midas — November 9, 2013 @ 4:16 pm
Exactly. I just installed Opera 6 because I wanted to see for myself, and they have a ‘Window bar’ that displays a tab for every window. Standard, this bar’s at the bottom of the screen, but you can place it at the top easily. Now what I want to know is what allthatiswrong thinks defines tabbed browsing, or a TDI. Yes, there’s no repositioning, and yes, there’s no option to open links in a new tab automatically. But right-click, ‘Open in a new window’, and you’ve got a new tab. And isn’t it the tabs that define tabbed browsing?
Comment by deviseatide — November 14, 2013 @ 11:23 am
I don’t define the terms. You may think it is semantics that Opera’s MDI was not technically a TDI, but that’s the facts. Which means in turn, Opera was not the first browser with a TDI. They may have been the first browser with multiple-pages-in-one-window functionality however.
Comment by allthatiswrong — January 5, 2014 @ 9:40 am
@allthatiswrong, and in fact nobody cares how it is done but how it works from perspective of end user.
These are only terms, maybe we need new one, like MDTI, Multi Document Tabbed Interface? 😛
I know exactly how it works from technical side, I’ve implemented it in the same way in my browser, Otter (combining QTabBar with QMdiArea), but be warned that MDI features are not yet exposed (so according to your definitions I have full TDI built on top of MDI, you can detach (but no DnD yet, QTabBar is a complex beast, proper visualization of DnD detaching is not easy to do) and rearrange tabs too :-P).
It looks and works exactly like TDI, and even toolkit offers MDI to be used as kind of simple TDI (ie. display tabs without need for additional widget) while offering also simple (comparing to this) tab widget.
MDI + TDI is simply superior (best of two worlds, while having no real negative side effects, for sure none for end user).
I’ll repeat, users don’t care how something works, they only care if it works correctly. 😛
Comment by Midas (aka Emdek) — January 5, 2014 @ 10:19 am
Opera fangirl here – I agree with you about Multiple Document Interface!
I also agree with the blogger here that Opera wasn’t first with tabs. From what I remember (having used Opera since version 3), the introduction of a tabs option seemed to be to make it easier for people already used to Firefox who were trying out Opera.
Anyway, MDI is especially handy when I want to compare things on two different webpages. In Firefox I can have as many tabs open as I want but still can’t get more than one of the webpages (not a tab for the page, the page itself) to show up on the screen at the same time.
Are there any add-ons/plugins/whatever for Firefox to have MDI with
Comment by Lindy — December 1, 2013 @ 10:53 pm
I would prefer to argue that the other browsers have, in fact, implemented a sub-standard attempt at Opera’s MDI-with-tabs interface, to which they’ve had to add tons of functionality (tab dragging for instance),and in some respects it’s still sub-standard (how do you tile 2 tabs next to each other in Chrome so you can, for example, watch 2 items simultaneously in eBay? A: You can’t, unless you split them onto separate windows.
So, whilst the pedant would agree with you – tabs were invented elsewhere – IMHO Opera’s implementation of “fake tabs” is actually superior to most people’s implementation of “real tabs”. Obviously, when Opera became a Chrome skin, all that went out of the window.
Comment by SargonD — October 13, 2015 @ 10:54 am
Maybe, I never liked Opera. They did things differently to other browsers for no good reason, issues a petty complaint to the EU because their browser was not selling, and claim innovations they have no right to. On top of all that, back in the day, most pages simply didn’t work well in their browser.
Comment by allthatiswrong — October 30, 2016 @ 1:39 am
analog_ is right. allthatiswrong, is, as per usual — wrong.
Comment by Cyberbop — August 17, 2011 @ 10:48 am
You can redefine words and revise history as much as you like, doesn’t mean Opera will have ever invented tabs.
Comment by allthatiswrong — August 18, 2011 @ 10:16 pm
That’s ridiculous. I switched to opera in 2001, back then it had a bar on top that held buttons that contained the names of sites you had visited. When you clicked the buttons, hey presto, the site appeared. As far as I can remember, they even called those buttons “tabs”. So they used a technique called MDI instead of one called TDI. Who gives a fff? As a layman, I will continue to call that tab-browsing. (When did they change to TDI? I never noticed a difference… what exactly is this extra functionality you are talking about? Oh you’re right, I don’t think you could resort the “tabs” with drag’n’drop back then. BIG difference!)
Anyway, for years opera was the only browser where tab-browsing actually worked! Until recently, you always had unwanted windows opening in IE and FF when trying to tab-browse. I think it still happens in IE…
Comment by mo — January 9, 2012 @ 1:54 pm
You are all wrong actually. It was Mozilla Suite which used real tabbed browsing first. Now known as SeaMonkey.
Comment by ThurahT — March 30, 2012 @ 12:39 am
Opera, did indeed use the first ‘tab’ browsing in a major browser, FF, IE, Safari all came to the party later. Yes FF and IE had the ability to do tabs but they did not work as smoothly as Opera (even if you class it as not tab browsing because of semantics). In real terms you could give the title of Tab invention to NeWS back in 1988, but without the modern internet back then, that could also be classed as word play.
The real way to see which started the Tab revolution is to go back and try all those browsers, I can tell you right now you will only find one browser back in 2000 that was using Tabs, and they worked in both Windows and Linux (by the by I only found Opera through the use of Mandrake (yes back when it had a real name not like now with Mandriva}). Honestly the only browser with any market share that had a working tab function (whether MDI or TDI) was Opera. If you don’t believe me go download and try them.
It matters little as Opera are the leader in virtually every field of innovation when it comes to browsers. I have noticed all the browsers follow with ‘speeddial’, ‘Paste & Go’, mouse gestures and all the right click options that I now see appearing on FF, IE, Safari that are straight out of Opera. Don’t get me wrong I love Firefox and have a great deal of respect for Chrome (absolutely no time for IE or Safari) and they all make for some interesting times ahead. I will keep using Opera time they stop making it, you can call me a fanboi, I would be happy to be called that, but more to the point I use a great browser that has some of the best security scores out, is fast and has more inbuild options than any other in such a tiny download.
Tabs are owned by Opera no matter how you try to change the technical differences. Have a great day all.
Comment by Horus — April 11, 2012 @ 3:15 am
It’s not semantics. A multiple window interface is not tabbed browsing, as much as you wish it to be the case. I wrote this article after downloading multiple versions to see which did come first and it was Mozilla software, sorry to say.
Opera has an underserved reputation for innovation. It is a subpar browser, which still have yet to catch up.
Comment by allthatiswrong — December 11, 2012 @ 4:07 am
Sorry for the typos, you can change them in your head. (o8
Comment by Horus — April 11, 2012 @ 3:18 am
I’ll be honest. I don’t really care whether Opera did it first.
However I don’t think NetCaptor did either.
Unfortunately for you, your sources lack reliable references, so I can’t really trust them. (NetCaptor has broken links for references, and Wikipedia is not completely reliable)
If we consider the MDI to be form of tabbed browsing, then Opera can claim to have had it since version 1.
I’m finding that this is just a game where every person involved is claiming to have done it first. It’s quite ridiculous.
What I do know is that Opera is a pretty good browser right now, it’s secure, and it does what I want.
I switch to a different browser whenever I’m having compatibility issues, but I still prefer Opera as my primary browser.
I agree with Horus when he said “I use a great browser that has some of the best security scores out, is fast and has more inbuild options than any other in such a tiny download.”
I have to install Opera or Chrome every time I log on to a college PC (No way am I using IE), Opera downloads and installs significantly faster than Chrome.
Chrome has better compatibility though.
I don’t really care what each browser said it did first. I know what I use, and that’s really all that matters for me.
Comment by 1204333kentleigh — September 21, 2012 @ 10:59 am
References not reliable? Wikipedia is fine for the articles I link to and you can download the versions of the software to see for yourself just as I did. If you’re concerned about verification then do it, it isn’t hard.
Also, Opera is one of the least secure browsers since it still has no support for DEP or WIC.
Comment by allthatiswrong — December 11, 2012 @ 4:15 am
You are absolutely right. The problem is that this myth is not only perpetuated by fanbois, the Opera Software web evangelist is actively spreading this lie: http://my.opera.com/ODIN/blog/300-million-users-and-move-to-webkit
“Opera innovations such as tabbed browsing, Speed Dial and data-saving compression that speeds up page-load, have been widely copied and improved the web for all.”
This is insulting.
Comment by zugu (@zugu) — February 13, 2013 @ 10:35 am
Which is the best web browser: Google Chrome, Mozilla Firefox or Opera?
This question can’t have a proper answer since it is base on what is your goal and what you do on internet If this question was on 2006-2008, I wouldn’t hesitate to say firefox but now the game has changed In 2006-2008 or older, the web browsing was…
Trackback by Quora — March 11, 2015 @ 3:23 am
Among major browsers, Opera did it first, before Mozilla.
The first browser with tabbed browsing was SimulBrowse: http://www.buzzfeed.com/josephbernstein/meet-the-man-who-invented-tabs#.vu6mBx700
It is true that the TDI was incorporated by the inventor into Mozilla in 2002. What is not true is that Opera introduced TDI in October 2002.
Opera introduced TDI in Opera 4, in June, 2000, predating Mozilla by two years: http://www.opera.com/docs/history/presto/#o40
Comment by Ciro Pabon — February 28, 2016 @ 7:20 pm
You’re wrong. What you call a TDI is an MDI. Opera had an MDI first, not a TDI.
Comment by allthatiswrong — October 30, 2016 @ 1:33 am
Opera’s MDI is what inspired tabs. Anyway RIP Opera, long live VIVALDI!
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Very helpful info. Thanks to the author/s.
Comment by ratulsikder — May 18, 2018 @ 2:20 pm
Thank from Mora Shenkle
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InternetWorks had tabbed browsing in 1994
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