Browser JavaScript

Browser JavaScript Explained

Browser JavaScript is a feature that allows Opera to automatically fix incompatible Web pages, out of date scripts, and pages that inadvertently block Opera. The script file is automatically distributed by Opera Software ASA, and can be used to apply fixes to specific Web sites, and specific scripts.

Browser JavaScript respects your JavaScript preferences, and will not be loaded if JavaScript is disabled.

Current browser.js status: disabled. How do I enable it?

Note: Opera also provides User JavaScript, which allows you to apply your own enhancements and fixes to Web pages. Additionally, Opera Software ASA runs the Open the Web initiative, which contacts the authors of problematic Web sites.

Keeping up-to-date

Opera automatically checks for updates to Browser JavaScript once every week. Any updates will be automatically downloaded and applied the next time a page is loaded in Opera.
Automatic checking is controlled by the Browser JavaScript and Check For New Opera settings in Opera6.ini.
Files are downloaded separately for each user of Opera, and you do not have to be an administrator of your computer to make use of this feature.
The Browser JavaScript is signed and distributed by Opera Software ASA, and should not be edited.
The file will be stored in Opera's profile folder. The Help > About screen will tell you where the profile folder is.

If you use a proxy server that requires user name and password to access the internet, please note that Opera will not request user name and password for an authenticating proxy in order to download ua.ini and browser.js. Site patching or upgrade notification will not take place if such proxies are required.

Enabling browser.js

If you have changed settings, or changed the file itself the browser.js feature may have become disabled.

Go to the Browser JavaScript setting and change the value to 2.
Click the "Save" button below the setting.
Re-load this page and check if the status message at the top says browser.js is enabled.

If this doesn't work for you, the file may be corrupted. Please follow the instructions on "checking for updates manually" in the next section.

Checking for updates manually

Opera downloads the file automatically once a week, but if you want to make absolutely sure you have the latest file you can follow these steps:

Go to the Browser JavaScript setting and change the value to 1.
Click the "Save" button below the setting.
Use Help > Check for updates.

Opera may tell you no new Opera version is available, but it will still check for a new version of the browser.js file.

Patches applied by Browser JavaScript

In most cases, when Browser JavaScript applies a fix, a message is posted in the JavaScript console (Tools > Advanced > JavaScript console) saying that the page has been changed.

Please note: Some of the fixes apply to specific Opera versions, or on specific platforms only.

Site fixes

saab

sniffing on saab.com and saab.de excludes Opera

www.opera.com

Browser.js status and version reported on browser.js documentation page

music.download.com

Fixing audio samples, old overlibwms library only detects Opera7

bbc.co.uk

Mobile BBC should default to mobile view

fileplanet.com

Fileplanet.com sniffing blocks Opera

moneta.co.kr

moneta.co.kr relies on IE quirks for CSS positioning

nmviewogc.cr.usgs.gov

National Map Viewer on USGS relies on Netscape detection for functionality

windowsmedia.com

Mobile Windowsmedia site does not trigger mobile view

americanexpress

AmericanExpress blurs form elements on click

amazon

Workaround for a layout bug in opera that only affects older versions, causing the search field on amazon.com and amazon.de to becoe 3 pixels wide.

epa.qld.gov.au

epa.qld.gov.au site uses capturing load events.

mail.google.com

Hides supported browser complaint in header

rec.feeds.yahoo

Make "add feeds" dialog work in Y!Mail beta

slashdot.org

Removes large focus areas covering the article area and the columns to the right.

anz.com

ANZ online bank form action URLs are incorrectly decoded

dell

browser sniffing on support.dell.com

ebay

Multiple fixes

google

Google calendar date selection fails due to order of blur and mousedown events

hp.com

HP shopping site is designed for smaller fonts

ibm.com

IBM driver download has HTML comments inside SCRIPT tag, breaks parsing

icicibank

ICICI online bank form action URLs are incorrectly decoded

mail.yahoo

Multiple fixes

orkut.com

Orkut uses curly braces in regular expressions without escaping them

scandinavian.net

Selects are reset if first option is removed in onchange

sony

UDM on sony.com breaks if insertRule throws exceptions

t-online.de

Multiple fixes

ulead

Ulead.com old Milonic menu

yahoo

Multiple fixes

able.co.jp

able.co.jp uses capturing event listeners

allabout.co.jp

Works around script scheduling bug on AllAbout

ameba.jp

Multiple fixes

aol.co.uk

AOL login hidden by IFRAME

aol.com

Multiple fixes

apple.com

Apple.com is written for higher resolutions than a TV

apple.viamichelin.com

Text on Apple store locator page is misaligned and overlapping

att.com

ATT / Bellsouth browser sniffing

barnesandnoble.com

Barnes&Noble uses "required" attributes on elements that aren't required

bbs.dzart.net

Avoid manipulating broken Discuz! markup on bbs.dzart.net

bbs.hxsd.com

Broken CSS makes fonts too small on bbs.hxsd.com

bbs.kafan.cn

Setting innerHTML to badly nested markup breaks forum layout on bbs.kafan.cn

belastingdienst.nl

enabling an alternate stylesheet while it is still loading is ignored

betfair.com

Betfair relies on firstChild defined on attribute nodes

bioware.com

bioware.com uses outdated HierMenus

blogger.com

Multiple fixes

bloglines.com

Bloglines, designMode case sensitivity issue

bnz.co.nz

bnz.co.nz use getYear when they should use getFullYear

bookryanair.com

Make Opera's built-in WF2 validation ignore required attributes on bookryanair.com

britannica.com

Prevent overwriting document with stats graphic on britannica.com

britishairways

Multiple fixes

budget.com

Budget.com: menu appears behind IFRAME "shim"

bugs.co.kr

bugs.co.kr reloads due to SCRIPT with for and event attributes

cajamadrid.es

Caja Madrid hides login form by CSS mistake

capitalone.com

CapitalOne login fails - cross-domain access on https disallows setting location

cdec-sic.cl

Old HierMenus on cdec-sic.cl

chase.com

chase.com field refocus from onkeypress-problem

cheaptickets.com

Cheaptickets new Function() issue workaround

chosun.com

Multiple fixes

continental.com

Continental.com document.activeElement fix enables airport choice popup

dancenter.com

Dancenter use getYear when they should use getFullYear

dcf-access.dcf.state.fl.us

Access Florida invalid markup problem

deviantart.com

Multiple fixes

diodeo.com

Offsets a very noticeable image in the header of diodeo.com

douane.nl

enabling an alternate stylesheet while it is still loading is ignored

drudgereport.com

Unable to read homepage

elkjop.no

Elkjøp UI breaks on Nintendo Wii because select-multiple by default doesn't un-select other options on click

estadao.com.br

Estadao redefines window.XMLHttpRequest with a function declaration

facebook.com

Multiple fixes

fedex.com

FedEx.com mangles tables by turning TDs into block elements

fotocenter.aol.de

AOL: browser warnings for various features of aol.de

foxnews.com

Fix captions

gallery.live.com

Live.com properties overwrite page from click tracking script

geoaccess.com

BlueCross browser sniffing prevents insurance search

ibank.isb.ru

browser sniffing breaks ibank.isb.ru

icelandair

jQuery script scheduling trouble on Icelandair

icicidirect.com

styling INPUT with text-transform can confuse users

iieye.com

IE detection prevents other browsers from accessing iieye.com

ingdirect.com.au

Multiple fixes

iple.com

Blocks floating flash ad on iple.com

irishferries.com

Unexpected text nodes in document.all breaks booking

isbank.com.tr

Multiple fixes

klm.com

KLM uses Gecko-specific originalTarget

kr.msn.com

head layout broken on kr.msn.com

ktfmembers.com

ktfmembers absolutely positioned flash blocks login

lgmobile.com

LG Mobile Flash does not load as expected because of missing type attribute

login.live.com

Hotmail: redirect to mobile version

m.reference.com

Mobile reference.com uses generic doctype

m.zdnet.com

Mobile zdnet.com should be displayed in mobile view

mail.126.com

can't read E-mail on 126.com due to XML parse error

mail.163.com

Multiple fixes

mail.google

Multiple fixes

mail.live.com

Multiple fixes

mail.yahoo.com

Disable Rich text editor

makemytrip.com

Multiple fixes

mapquest.com

MapQuest uses .all collection with text nodes in

maps.google

Google maps eval callback

maps.live.com

Multiple fixes

maps.ubiest.com

Ubiest.com uses CSS filters if document.all exists

marktplaats.nl

Can't add article to favourites because setting link.search has no effect

maybank2u.com.my

maybank2u, onresize event causes a refresh whenever the softkeyboard is opened

microsoft.com

Unknown fix

millenet.pl

Semicolon insertion fails after do..while() conditional

mobil.debitel.de

Fix image grid

mobile.answers.com

Mobile answers.com displayed as desktop site

mobile.handango.com

mobile.handango.com pages are displayed in overview mode, since they are declared without doctype.

mobile.microsoft.com

Mobile microsoft.com should be displayed as a mobile page

mobile.orange.ch

Fix for table align making tables behave as inline on mobile.orange.ch

mobile.youporn.com

Mobile youporn.com uses generic doctype

monster

Monster category tree broken by their selectNodes function overwriting .text on nodes

msnbc.com

MSNBC sniffing hides Flash content

music.mu-mo.net

mu-mo.net uses SCRIPT for..event.. syntax

n-gage.com

N-Gage plugin sniffing does not give Flash to Mac Opera

namooya.com

Namooya.com main flash does not appear

nbc4.tv

NBC4.tv uses capturing load events

nbcolympics.com

NBC Olympics site uses capturing load events

nectar.com

Nectar uses getYear where they should use getFullYear

netian.com

Moves the absolutely positioned SMS div on netian.com (after logging in)

netpia.linkprice.com

Clears popups that are visible after loading subpages on netpia.linkprice.com

news.bbc.co.uk

Multiple fixes

news.msn.co.kr

news.msn.co.kr navigation bar is offset from the page

nick.com

Nick.com flash detection fix

nokia.com

Fix nokia header

nrg.co.il

NRG.co.il saving articles does not work

o2active

o2active.de, making sure narrow centered column does not appear off-screen

orbitz.com

Orbitz new Function() issue workaround

orkut.com

Multiple fixes

pda.naver.com

pda.naver.com appears half-offscreen

picasaweb.google

Picasaweb browser sniffing removes functionality Opera has no problems with, for example slideshow

poczta.onet.pl

poczta.onet.pl RTE broken in 9.50

pogo.com

Multiple fixes

prisjakt.nu

prisjakt.nu capturing load events on back navigation

rabobank.nl

Rabobank cancels t keypress

redfin.com

Solve Dojo script scheduling trouble on redfin.com

reviews.cnet.com

CNet videos: document.write adds a script that depends on variables defined later

sabadellatlantico.com

SabadellAtlantico use getYear when they should use getFullYear

santandertotta.pt

Santandertotta.pt IFRAME resize script detects Opera

sayclub.com

hides id and password background images that are text input backgrounds

sfile.ydy.com

Avoid manipulating broken Discuz! markup on sfile.ydy.com

show.co.kr

Pre-filled text as INPUT background not cleared on focus

shutterfly.com

Array splice throws on 0-length arrays, breaks Shutterfly.com

sina.com.cn

Unknown fix

spaces.live.com

Multiple fixes

sperrysoftware.com

Nested tables with 100% height are not laid out as expected, menu is pushed down

sports.donga.com

Blocks floating flash ad on sports.donga.com that cannot be closed

spreadsheets

Faking support for event object properties layerX and layerY

star.moneytoday.co.kr

Clicks on a link to display the front page story in an iframe on star.moneytoday.co.kr

sun.com

Menu entries off-screen on sun.com due to font size

surveymonkey.com

Unknown fix

sytadin.fr

Sytadin.fr IFRAME resize script detects Opera

tdwaterhouse.ca

tdwaterhouse.ca login fails - cross-domain access on https disallows setting location

teletekst.nos.nl

Teletext focus fix

time.com

time.com script causes reload loop if UA contains "Windows CE"

tiscali.it

Allows some frame nesting on web.tiscali.it

tistory.com

two login buttons on tistory.com

toeslagen.nl

enabling an alternate stylesheet while it is still loading is ignored

united.com

United.com flight search problem: hidden images do not load, so no onload event

usairways.com

USAirways is not compatible with WF2 spec required attribute

video.nbc.com

NBC.com video problems

vkontakte.ru

Multiple fixes

vodafonelive.de

Fix dummy password field

wachovia.com

Viewing checks calls createElement with markup strings if document.all exists

walla.co.il

Multiple fixes

walmart.com

Walmart hides "find in store" popup unintentionally

westjet.com

Westjet browser sniffing causes reload loop

wetter.rtl.de

Font size adjustments to avoid overlapping on wetter.rtl.de

worldofwarcraft.com

Mouseover popups do not appear due to document.all sniffing

www.ojogo.pt

Fix iframe width

yam.de

Unknown fix

yellowpages.com.au

Yellow pages event capture fix

ynet.co.il

YNet article comments display fix

zdnet.com.com

ZDnet video site plays non-existing files if browser is Opera

aumypage.duogate.jp

au my page XMLHttp re-use issue

live.vodafone.com

Display Vodafone's Google search site in Normal Zoom by default

mobile.vzwapp.com

VZW mobile portal does not trigger mobile view

wap.smart.com.ph

Multiple fixes

xhtml.emome.net

emome.net wap portal does not trigger mobile view

https://www.bookryanair.com/skylights/cgi-bin/skylights.cgi

Selects are reset if an option is changed from onchange.

mk.co.kr

mk.co.kr requests a lot of additional javascript after checking document.all - customer requested fix for load time

Maconomy/MaconomyPortal

Fix unload form submit behavior on Maconomy portals

wp-admin

Wordpress Admin prev/next link styling makes them unclickable

Patched scripts

Old versions of the following popular script libraries, all of which fail in Opera:
- "Sothink menus" versions 3.72 and earlier; changes browser detection to make the menus use the correct code in Opera.
- "Milonic menus": changes browser detection to make the menus use the correct code in Opera.
- "HierMenus": changes browser detection so the menu is not disabled in Opera.
- "Likno AllWebMenus", builds earlier than 498; changes browser detection to make the menus use the correct code in Opera.
- "Menu/Pop Menu": (HV Menu); changes browser detection so the menu is not disabled in Opera.
- "Ultimate Dropdown Menu": changes browser detection so the menu is not disabled in Opera.
- "OpenCube menus": changes browser detection to make the menus use the correct code in Opera.
- "Coolmenus": changes browser detection to make the menus use the correct code in Opera.
- "DynAPI": changes browser detection to make the library use the correct code in Opera.
- "Transmenus": changes browser detection and code to make the library use the correct code in Opera.
- "TinyMCE" 2.x versions: works around a bug that prevents enabling editing mode. 3.0.x versions: works around an issue that breaks the enter key
working around incompatibility with prototype - argument extends array but not all methods work correctly
Prototype requires function.toString to return a unique string per function
The required attribute does not take the value false according to WebForms2 - remove "required=false" from form elements
Remove non-breaking spaces inserted by rich text editing bug
Fake support for MozOpacity properties on style object
Generic JS library patches
Allow scripts to define reserved word top, but not not allow javascript: URLs to read the custom value
Compatibility layer for Google Gears initialization script
Router configuration SCRIPT in OPTION tag fix
PDF security patch
document.domain can not be set to last TLD
NHK and iui.js relies on array indexOf

Note to webmasters

There are several reasons why Opera might modify your pages. These include:

Opera may prevent a browser detect on your pages from causing problems.
Opera may fix incompatible, invalid, out-of-date, or problematic code used on your pages.

If you think Opera is modifying your page incorrectly or unnecessarily, or if you have removed the cause of the problems, please report it in our bug tracking system.

If you wish to disable Browser JavaScript to allow you to test your fixes, you can do this by setting Browser JavaScript to 0 in Opera6.ini. A quicker way to do this is to access opera:config#Browser JavaScript, since toggling this setting in opera:config does not require restarting Opera.

Opera