The Secrets of Firefox about:config

jcatcw writes "While Firefox is very customizable, many of its settings aren't in the Options. Each setting is named and stored as a string, integer, or Boolean in a file called prefs.js and accessed via about:config from the nav bar. Computerworld provides instructions on 20 tweaks for speeding up page loads, making tabs behave, reducing memory drain, and generally making the interface act the way you want it to. Customization also comes through the must-have FF extensions (but be sure to skip these)."

While it's nice..

Do not tune stuff that is hidden unless you know what you are doing.

Re:While it's nice..

> Do not tune stuff that is hidden unless you know what you are doing.

s/Insightful/Redundant/

This is Slashdot: we all think we know we are doing :-)

Re:While it's nice..

I particularly love the "pipelining" part. Send requests before getting valid acknowledgments from previous requests. ...

It's rude, annoying and breaks the rules/protocol.

From RFC 2616 (HTTP/1.1) [ietf.org] section 8.1.1:

HTTP requests and responses can be pipelined on a connection. Pipelining allows a client to make multiple requests without waiting for each response, allowing a single TCP connection to be used much more efficiently, with much lower elapsed time.

Re:While it's nice..

It isn't faster for everybody, it doesn't work with all servers...

Re:While it's nice..

If it's valid behavior according to the protocol, and it's faster, and it's not bad nettiquette, then why, pray tell, isn't it on by default?

Because some servers violate the protocol by responding incorrectly to pipelined requests. At least, that was the reason 2 years ago.

Re:While it's nice..

This is a tactic spammers use with mail servers. It's rude, annoying and breaks the rules/protocol.

RFC 2920 [rfc-editor.org] is the SMTP extension for pipelining. Pipelining is a perfectly valid strategy to reduce the time it takes to send mail by reducing the number of round-trips.

What's rude is violating the RFC that says that certain round-trips are required and the spammers tend to violate those rules (such as asking if a message body can be sent before actually sending it, and waiting for the server's introduction message before the client introduces itself). Pipelining itself is actually quite good.

I won't comment on HTTP pipelining because someone else did already.

Re:While it's nice..

http://subversion.tigris.org/faq.html#in-place-imp ort [tigris.org]
Install Subversion, and use it on your config files.
Subversion: it's not just for projects anymore.

Re:While it's nice..

So if these options really make pages load faster, offer less memory drain, and even feed the dog, why aren't they a part of the settings to begin with?

Basically, because, although they may give more speed, they have drawbacks as well. Your question is like asking, ``If people can overclock their processors to so much faster, why isn't it overclocked by default?''

Re:While it's nice..

Why? He's 100% right! Just follow the instructions and you are all set with no chance of there being problems. You see, the instructions on that web page clearly state in bold letters: "Keep a log of everything you change, or make backups."

So, either:

• Firefox acts weird or doesnt run at all, and you restore prefs.js from backup and have no problems
• or it worsens performance, and you restore from backup and have no problems
• or it improves performance and you happily surf away and have no problems

So, because he is correct, he's a fanboy? With IE, you run the possibility of having to do much more than restore a preferences file if you hose something. With Firefox, if you follow the instructions (and something goes wrong), it takes you a few extra seconds to restore the file to original state and "nothing major" happens (other than a wasted few minutes in total trying the tweaks).

So, if he's a fanboy, what does that make you? Just curious.

Re:While it's nice..

Firefox, while better than IE7, is a fucking hog and getting worse by the release. Why should users, who are already iffy about switching to Firefox, have to go through archaic setup commands in order to have the browser work well?

Firefox works well with the default settings. If you have to go into about:config and twiddle parameters, there is something very wrong with your Firefox setup. Try creating a new profile and see if that fixes the problems. In reality, the settings suggested in the article can slow Firefox down (by setting the initial paint delay too low), cause sites not to display properly (by using pipelining with servers that don't understand it), and get you blocked from servers (by setting the maximum connections way up). You can avoid all that trouble by sticking with the defaults.

Extensions to Avoid?

I thought we agreed that ComputerWorld article was mostly crap...

I just want

I just want to make it stop going to Google when it's looking up a URL. If it can't find it in DNS, I want it to return a 404, not ask some fsking company where they think I should go.

I tried changing every entry that mentions google.com, and sometimes it still queries. WTF!

Re:I just want

try this setting:
browser.xul.error_pages.enabled

set it to "true"

Re:I just want

If it can't find it in DNS, I want it to return a 404

404 is an HTTP status code. If firefox cannot find the server you want to connect to, where do you want that 404 to come from?

Tabs

In Soviet Russia, Firefox keeps tabs on YOU!

Camino?

I still use Camino [caminobrowser.org], a Mozilla-based browser for OS X. Is there a similar guide to configuring Camino options or do most of these work as is?

Re:Camino?

Did you even bother to try it out? Camino's about:config page is almost identical to FF's page. Any options that are named the same in Camino as in FF will do the same thing. (Camino is just a different front end on Gecko, and about:config options are almost all Gecko options, not browser specific.)

Ha, I can reduce my "must have" FF list to one

1) Install Stumble Upon 2) Set your topic to FireFox 3) Stumble Dollars to donuts, the first Stumble you hit is someone elses TopN list of must have extensions, which is pretty much a mirror of FF most popular extensions, so there ya go.

link to one page article

here [computerworld.com]

Re:link to one page article

Who modded that offtopic? maj1k posted the "print this article" link so we didn't have to wait seven times for ad-ridden pages to load.

Foons!

Well, a lot of these "tweaks" will have negative effects.

Example: nglayout.initialpaint.delay as 0. This will slow rendering of the page as it causes reflows. Fools.

Re:Foons!

Opera has sensible pipelining defaults. Most "Firefox tip" articles have you set them to values that when combined with other network settings makes your browser appear like a misbehaving robot, proxy, or hacking attempt. Firefox with sensible values doesn't get blocked.

Re:Foons!

Damn right. Here's what mozilla says about nglayout.initialpaint.delay [mozillazine.org]

Lower values will make a page initially display more quickly, but will make the page take longer to finish rendering. Higher values will have the opposite effect.

Which option to make the Firehose work again?

Using Firefox on FC6, the Slashdot firehose stopped working for me a while back.

The thumbs-up/down thingies don't do anything anymore. I tried turning off the NoScript extension, but that didn't seem to help. I also have Adblock+ installed.

Any clues?

Re:Which option to make the Firehose work again?

set org.slashdot.dont_make_changes_on_the_live_server_ yes_im_talking_to_you_cmdrtaco=1

A bigger question

Is why useful tweaks are hidden behind and obscure and risky-to-use interface like about:config. If the tweaks are worth doing, shouldn't they have first-class support in the main configuration GUI?

Re:A bigger question

Perhaps these tweaks are hidden because they are *not* worth doing?

Re:A bigger question

Listen sonny, as a network admin I perform 'miracles' every day with a CLI and hidden options in config files. It impresses the PHBs, earns respect and keeps my salary up. And now you want to further trivialise my job with more GUI options. Oh for the good old days when all we had were ones and zeroes.

Re: A bigger question

Is why useful tweaks are hidden behind and obscure and risky-to-use interface like about:config. If the tweaks are worth doing, shouldn't they have first-class support in the main configuration GUI?

One philosophy is to nanny the unwashed masses away from "advanced" options. A second is that there's not a lot of reasons to support every possible option in a UI, especially if some of them are rarely used.

FWIW, I used to change some stuff and it would be back to the default next time I started the broweser. Ditto if I changed it in the config file. It finally took when I changed it in the GNOME configuration manager; I guess it was masking the application-specific configs.

official mozilla reference

http://kb.mozillazine.org/About:config_entries [mozillazine.org]

Why aren't these real options?

Some of these tweaks cut down on memory usage. Given that there are still plenty of computers with 512MB of ram (e.g. notebook computers), you don't want applications pinning 100% CPU or memory as it slows down the rest of the system. This is more important with notebook computers, since a second lost through CPU usage or hard drive thrashing is a second lost from battery charge.

The notebook I'm using right now has this amount of memory, and was easily available in stores 1 year ago. Last time I checked, a web browser should never require the absolute latest system for day-to-day operations (which include having another application in the background, such as a word processor or even MSVC 2005.)

a little OT kinda, but the video downloader ext...

...works really well if you first watch the video you want to download, putting it in your cache. Then going to video downloader, and regardless of the file size, takes just a few seconds and you are done. Apparently it can grab it from your cache and make it a file on you system (very little for it to really do - very low bandwidth to convert).

In fact, it seems to me that when it doesn't work, "service not available" only happens when I don't watch it first, not in my cache.

Tee Hee

Set general.config.obscure_value to 42 for a special treat :D

The Art of Performance Tuning -- a Fable

A long time ago, when computers remembered using little donuts made of rust, I worked on on a mainframe computer system (CP/V) that supported batch, timesharing, realtime, the works. It had performance monitoring tools, and a large basketload of parameters for sys admins to twiddle.

One of our favorite parameters was SL:BB, documented as batch bias, an input to the process scheduler. When someone called or wrote to us saying they were having problems with performance tuning, we usually suggested they redo their tests varying the setting of SL:BB and let us know what happened. Try different values, 0, 1, 5, 20, 50, 100, things like that. Try it and get back to us.

And lo, they would go off and redo performance runs, and report back.

And we would collect their results and go and muse over them, usually over beer.

SL:BB told us a lot about the user, because SL:BB was a knob that wasn't connected to anything. Oh, the value was range-checked by the parameter setting tool, and dutifully stored in memory, and displayed on performance displays, but it didn't change system performance in any way at all.

That's not what the documentation said, but who believes documentation? We had plans for SL:BB, we just hadn't gotten around to writing the code yet.

So if the user reported that setting SL:BB to 25, but not 24 or 26 gave them incredibly better (or worse) results, we definitely factored that into our analysis.

Those that reported back that the setting of SL:BB didn't make a damn bit of difference, and there were some, we honored as brothers, took into our confidences, and shared beer with at the soonest opportunity. Their bug reports and feature requests received far more attention, for they had passed an important test.

And how many of these Firefox parameters are like SL:BB?

Re:The Art of Performance Tuning -- a Fable

"The general.config.obscure_value preference specifies how the configuration file is obscured. Firefox expects that each byte in the file will be rotated by the specified value. The default value is 13. If this value is left unchanged, then the configuration file must be encoded as ROT13. Autoconfig will fail if the cfg file is not encoded as specified by this preference. A value of 0 indicates that the file is unencoded-- i.e. it is unobscured plain text. It is recommended that you set this value to 0. (This will allow you to skip the encoding step in part 3.)"

Hee.

Still can't turn off favicons in the bookmark menu

I really don't like favicons in the bookmark menu. Added in firefox 2.0, they force the menu linespacing to be bigger, so I fit less items in a screenful, and the site that I used to know was 6 inches down the screen isn't where I'm expecting it to be anymore. I understand why some people like them, but for me they are a distracting rainbow coloured mess.

Guess which one of the billion or so features in the UI I can't turn off? I can use about:config to remove them from the URL bar, and the tool bar, where they were actually somewhere between bearable and useful... but in the bookmarks menu where they annoy me, I'm stuck with them.

I've installed a plugin that turns custom ones off, so they all look like 5 cyan jellybeans (wtf?) so they are a bit less annoying, but why can't I banish them?

Re:Still can't turn off favicons in the bookmark m

In Firefox 2.0.3, I opened up the DOM inspector, chose the main window, and started drilling down in to the element tree: I found the icons which you loathe.

Open up userChrome.css (in your profile: [profile dir]/chrome/).

In it, the following CSS rule should work to hide the icons:

.bookmark-item > .menu-iconic-left > image { display: none; }

(This selector appears in chrome://browser/skin/browser.css, if you know where that is).

kdawson...

KDawson is the new Zonk? Given the quality of the articles he is approving these days, he would soon surpass Zonk in crap-o-meter.

Hacking Firefox

Gah. Why is it that these people insist on calling anything not found on the main options page "hacking"? As for the above questions - usually the reason things like that are 'hidden' is to stop people fiddling with them. A good example is the old 'coolbits' entry in the registry for nVidia cards - the overclocking functionality was there, but you had to do something non-standard to enable it. That way, the company's ass is covered if you melt your card; you can't pretend you enabled the options accidentally. Since Firefox is free and nobody is paying tech-support, I'm not sure why these things aren't available - but the fact of the matter is, anyone messing around with fundamental parameters should _not_ be the kind of person who lets random articles on the internet tell them what to change.

Thunderbird also...

You can configure many settings in Thunderbird using a similar interface. However, in Thunderbird you can get to the config section from the Options menu Advanced tab. I have reduced the size of the attachment icons this way. set mailnews.attachments.display.largeView to False.

great timing, I needed this article today...

This morning at work (don't ask why I was surfing the web at work!) I launched FF and opened six tabs, each with a fairly common site: NOAA, TD Ameritrade, Yahoo Finance, etc. Later in the day, perhaps 6 hours later, I noticed my machine (IBM T42) was swapping and noticeably. The Windows XP Task manager, with tasks ordered by memory usage, showed that FF was using 270MB of RAM, far more than any other application. During the day I had closed and opened a few tabs, and reloaded a few pages, but my god -- 270MB of RAM? I am using FF 2. Tomorrow morning I'll try changing browser.sessionhistory.max_total_viewers to 0, and hopefully that will resolve my issue. I'll report back.

Configuration of plugins missing..

The one thing that you cannot configure in FF is the order or preference of plugins. Say that you have 2 or 3 plugins that support the same filetypes, you can't configure if which filetype opens with which plugin. In situations where the support is broken by a plugin, as it often happens in linux with eg. streaming windows media, you are stuck with the plugin that doesn't work and you can't change it. If you remove it, then you loose functionality, because the others might not work with filetypes that this one supported well.

Opera Version

opera:config

"Be sure to skip these"

No, thanks. Following the parenthetical link I landed at TFA, which was little more than Computerworld whining about how people using the Adblock and AdblockPlus extensions would deprive it of ad revenue.

Computerworld actually had the gall to suggest switching to blocking software that's more selective, allowing you to cherrypick ads to block "while continuing to support the sites we love by allowing most ads to appear." Oh, what a cynical dearth of principles: block our competitors' ads, but NIMBY!

Nope, I'm an equal opportunity Scrooge, and for my free-as-beer money these are two of the most useful Firefox extensions around.

Hidden slashdot tweaks THEY don't want you to know

I've found some secret hidden tweaks you can make to Slashdot articles, just by editing this thing called a URL. For instance, you can set the comment threshold HIGHER than 5 by editing the number after "threshold=", ensuring only the absolute best comments (apparently none in this story meet that standard yet). Why do they hide useful options like this from us?

Re:Hidden slashdot tweaks THEY don't want you to k

For instance, you can set the comment threshold HIGHER than 5 by editing the number after "threshold="

It works the other way too; you can set the threshold to -2 or lower via the URL. Most people never get to see such posts, which is the whole point- you'd be shocked if you knew what was there. Things modded down to -2 include:

• Secrets of the Illuminati
• The truth behind the JFK assassination
• Clear evidence that Steve Jobs is not God, Bill Gates is not the devil and Steve Ballmer is not *actually* a chair-throwing ape
• Anything linking to Zonk's blackmail pics of Taco and Cowboy Neal

The real scandal is Firefox's cookie options.

Correct me if I'm wrong (and I'm sure you will), but I seem to remember that Firefox had an option in its cookie preferences dialog that allowed you to restrict cookies to those set by the originating site. It's a nice option, as it marginally increases privacy, and probably should be on by default. But as of 2.0, that option is gone. It still exists in the about:config, but less-sophisticated users are stuck with the default "allow sites to set just about any cookie they want" setting.

One must wonder: why would the Firefox team remove that option? The only conspiracy theory I can dream up is Google's involvement...

Can I get one script

Can I get a single script/installable/whatever to tweak all these in one shot?

Firefox off track

about:config is the worst method of changing preferences that I have ever seen.

about:config is evidence of feature creep, and hence evidence of Firefox turning into the Mozilla browser.

Past versions of Firefox have added additional features such as image resizing. And guess, what, users are not given the ability to disable this; they must enter into the cryptic about:config.

about:config is an HCI catastrophe.
 

The only about:config secret I need

Is how to turn off that fricking auto typeaheadfind. I'm not typing apostrophes on a blank web page. I'm typing them into a text box. I'm typing them into the GOOGLE TEXTBOX (plain-vanilla homepage era). This is not a feature. A feature is an added capability. This is a BUG. I'm not disabled; I don't need accessiblity assistance. If I want to find text, I'll type ^F. If I'm typing an apostrophe into the Google text box, I don't want to search for text on that empty page, I want to search for my quoted text. Maybe they could add an accessiblity.typeaheadfind.goawayandnevercomeback. Or maybe they could even obey the EXISTING typeaheadfind options. Or map the key to a ~. Or, even, now this is a radical idea, stop erasing people's bug reports telling us it's a feature, and fix it.

How to change scroll speed (works for Gnome!)

about:config
mousewheel.withnokey.sysnumlines -> false
mousewheel.withnokey.numlines -> any number, personally I use 6.

browsing slashdot ..

Why is is that when I click the on the main slashdot page, it takes ages and hangs on sites like e.nvero.net, images.slashdot.org, zdmp.net, smartgetting etc. I know it doesn't matter on your fast connection, but it does mean I [waiting for images] don't [waiting for images] have [waiting for pages2.googlesyndication.com] to [waiting for images] wait [waiting for doubleclick] so [waiting for images] long [waiting for adserver] for [waiting for images again] a [waiting for google analytics] complete [ f*****g finally] page to appear ..

It's not just slashdot but most sites, clicking the back button doesn't make a difference as it still reloads from the web site. I thought the cache stored pages for resuse.

Documentation

My question is simple: Is there good, concise documentation of the about:config page and it's options?

If yes, where is it and is there an an easy why to find it?

If no, why not? If this is all about choice, should people be able to learn about their choices?

Re:Documentation

My question is simple: Is there good, concise documentation of the about:config page and its options?

Yes.

If yes, where is it and is there an an easy why to find it?

MozillaZine Knowledge Base Article on about:config entries [mozillazine.org]

It is the first page Google finds when you search for "about:config". I'll let you decide whether that's easy to find.

If no, why not? If this is all about choice, should people be able to learn about their choices?

If there wasn't, you'd be able to put it in the Knowledge Base yourself.

Hidden configs in general

My opinion about hidden configs is that if they were meant for the end-user to dick with, they'd be on a friendly Options dialog.

If there's a very useful hidden option, it should be promoted to a visible widget. The fact that Firefox devs are often lazy about such "little" things is the main source of problems. They spend too much time building flashy (and useless) features instead of tightening the existing experience, which is why you see a new FF 3.0 attention-grab every couple of days. They've gone completely Microsoft!

Re:Opera!

about:config and about:opera have existed in Opera for ages.

• about:config has always existed in Firefox and Seamonkey
• It's opera:config in Opera.

I love how firefox/mozilla takes features that existed in Opera for years and try to hype them up as new "features" in firefox!

I've never seen Mozilla hype this.

Another reason firefox is over-hyped and doesn't compare to Opera really.

Here is why Opera doesn't work for me.

• I need an equivalent to Google browser sync [google.com] that can synchronize between browsers on Linux, Windows and OS X.
• Opera doesn't work with certain bank sites while Firefox (and even Konqueror) does
• I need something like flashblock [mozdev.org], which I can even get in IE (through a registry setting) and Konqueror (built in).

In particular, the first point is the most important to me.