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Setting hidden Mozilla preferences Web Browsers
Mozilla has some preferences that are not listed in the Preferences panel of the app. Some of them are nevertheless quite useful, most notably (at least to me) the number of network connections that Mozilla will open.

To begin with, type about:config in the URL location field. Mozilla will now generate a page that lists all the prefs it understands and what values they have.

If you scroll down the page, you'll notice the settings that start with network.http. Mozilla uses relatively few concurrent connections per default (24 overall for all windows and 8 per server -- two persistent). Now if you happen to have a rather fast connection to the Internet and/or you are browsing mostly on a Intranet you can get Mozilla to use much more connections (if it needs to, that is).

Read the rest of the article if for the details on how to edit your Mozilla prefs file...

[Editor's note: Please read the comments for an important note about how to crate a new prefs file, as opposed to editing the master!]

First of all you need to find Mozilla's preferences file. Open a Terminal and enter in this command in your home directory:
find . -name prefs.js
You'll get something like
Now you can edit this file (I use the SimpleText that came with the Developer Tools) to include the fillowing lines:
user_pref("network.http.max-connections", 128);
user_pref("network.http.max-connections-per-server", 48);
user_pref("network.http.max-persistent-connections-per-proxy", 24);
user_pref("network.http.max-persistent-connections-per-server", 12);
N.B. the settings above are the equivalent of Thors hammer and will put considerable load on the remote site, but in my case Mozilla loads pages much quicker.

BTW: you can use the following Terminal command to edit your prefs file:
open -a /Developer/Applications/Extras/
`find ./Library -name prefs.js`
[Shown on two lines for readability; insert a space between "" and "`find"]. This will open all prefs.js files in your home directory in SimpleText in one go!
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Great Tip.
Authored by: skotmiller on Jan 13, '02 05:28:54PM

That sped up load times a lot.

Anyone know how to disable and/or remove the components. I don't use mail, messenger, composer, addressbook, or anything other than the browser. I'm thinking that it would speed up application load times. I've tried removing the components from the pkg, but it just crashes when I startup the app.

Thanks for the good tip though,

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WRONG! edit user.js not prefs.js
Authored by: risc_abacus on Jan 13, '02 05:44:49PM

I am sorry but this tip is SOOO wrong. Users should never edit prefs.js. Instead users are supposed to make a new fie called user.js and edit that. Editing prefs.js could case problems.

See and

other than haveing users edit prefs.js instead of user.js this is a great tip.

[ Reply to This | # ]
RE: WRONG! edit user.js not prefs.js
Authored by: skyko on Jan 14, '02 01:41:08AM
Thanks for pointing this out! Nevertheless the prefs will end up in prefs.js (Mozilla will take them from there and write them into prefs.js -- tricky if there's a pref setting in the prefs.js already ;-). What I'd really like to see is a possibility to edit the prefs right there in the about:config page!

[ Reply to This | # ]
Authored by: Anonymous on Jan 14, '02 12:53:46AM

This tip made a conciderable difference! I'm going to have to challenge my IE using friend to a web page loading contest to see which browser is faster.

[ Reply to This | # ]