Web Paint-by-Number
Browser Compatibility

Web Paint-by-Number should work reasonably well with any of the more common modern browsers. However, webpbn.com uses some very complex Javascript programs that exercising many rarely used browser features. Some of the code is extremely browser-dependent, so that different versions had to be developed for each different browser. Some features work imperfectly in some browsers. There are also substantial differences in performance.

The code on this site is in continuous evolution, and I generally test each new version of the site only with current browsers, not with outdated browsers. A lot of code that was there to support old browsers has been stripped out (since I can't really maintain it anyway). Generally, you shouldn't expect browsers more than a couple years old to work here.

What browsers work best with webpbn? I think the best options are Firefox (version 2.0 or later), Safari (version 1.2 or later), or Chrome (any version).

Firefox, Camino, Netscape, and Mozilla

Firefox and it's relatives are all built on top of a page rendering engine called "Gecko". Most recent Gecko versions work great with Web Paint-By-Number, except for version 1.7 which had a number of small problems that I was never able to work around. All Firefox versions since 1.5 work fine.

Gecko version Works? Mozilla Suite Firefox Netscape Camino
Gecko 5.0 Great! - Firefox 5.0 - -
Gecko 2.0 Great! - Firefox 4.0 - -
Gecko 1.9 Great! - Firefox 3.0 - -
Gecko 1.8 Great! SeaMonkey 1.0 Firefox 1.5, 2.0 Netscape 9.0 Camino 1.0
Gecko 1.7 Flaky Mozilla 1.7 Firefox 1.0 Netscape 7.2, 8.0, 8.1 Camino 0.8
Gecko 1.6 Probably OK Mozilla 1.6 Firefox 0.8 - Caminio 0.7+
Gecko 1.4 Probably OK Mozilla 1.4 Firefox 0.6 Netscape 7.1 -
Gecko 1.0 Probably OK Mozilla 1.0 - Netscape 7.0 Camino 0.7
Gecko 0.9 No Mozilla 0.9 - - Chimera 0.6

Older versions of the Epiphany/Galeon browsers are also based on Gecko, and work fine, but there is no consistant mapping of their version numbers into Gecko versions.

In Firefox 3.0 and later, there is a "Zoom" option which scales the whole page. It doesn't do it perfectly, however, so puzzles that have been zoomed in or out tend to have black lines of inconsistent width separating the squares. The browser may even remember zooming you did in a previous session and start up already zoomed in. So if the black line thicknesses seem messed up, try zooming in or out.

If you use Firefox with the (generally very nice) Adblock extension, you'll have to turn "Quickblock" off. Quickblock let's you make images that are not links disappear by doing a "shift-double-click" on them. This is a real problem in Web Paint-by-Number because it makes parts of the puzzle disappear, causing various strange effects. You can tell you have Adblock with Quickblock turned on if the word "Adblock" in the lower right corner of your browser window has a solid or dotted underline. You can turn it off on a PC with "control-shift-k" or on a Mac with "command-shift-k". Repeat the command until the underline on the "Adblock" word disappears. If you never knew what shift-double-click did, or what the underline on the "Adblock" word meant, you aren't alone. This is scarcely documented anywhere.

The FireGestures plugin can also interfere with webpbn.

Firefox users with three mouse buttons will typically find that the middle mouse button performs any of several different functions, depending on the browser configuration and version (scrolling, opening new windows, opening new tabs, pasting URLs). The web paint-by-number program cannot disable any of them, and changing the browser configuration does not seem to help. So the middle mouse button cannot be used in Firefox. (I've tried submitting patches to Mozilla to fix this bug, but haven't quite managed to talk them into accepting them yet.)

In Camino, control-click brings up a menu. Use alt-click instead.

The gecko 1.7 based browsers were usable, but had many small glitches. They seemed to have some notion that when you clicked on an image you were selecting it and maybe want to drag it someplace. They seemed to put white boundaries around the images and sometimes do other strange things, which caused squares to shift around and boundaries between squares to disappear, generally making a mess. My recommendation if you have these problems is to upgrade to Firefox 1.5 or later.

Though Netscape 8.1 is still based on the Gecko 1.7 engine, I haven't seen the typical Gecko 1.7 rendering bugs in it. Maybe some of the Gecko 1.8 bug fixes have been applied. In any case, in Netscape 8.1 you have the option of rendering the page with the IE engine instead (though this gets you the IE bugs with double-clicks).

Internet Explorer

If you are using any version of Internet Explorer before version 9, please upgrade as soon as possible as a personal favor to all the world's web developers. For a decade or so, every website had to have special work-arounds for all of Internet Explorer's bugs. Users of Internet Explorer thought they had a working browser, but that was entirely an illusion created for them by the hard work of millions of site developers. Internet Explorer 9 changed all that. Microsoft actually fixed the bugs and is a pretty good browser.

Unfortunately, you need to have Windows 7 or later to update beyond IE 8, so many users are still stuck with a broken version of IE. Webpbn still has all the IE bug workarounds, so these older versions, anything from version 5 on, will mostly work, but not as well as IE 9 does.

The most important bug I was never able to work around in older versions of Internet Explorer was with double-clicks. Web paint-by-number users frequently click twice quickly as they cycle through colors for a cell. Web browsers typically interpret this as double-click. With most browsers this is not a problem, but in IE, for the second click of a double click, no mousedown event is sent. In web paint-by-number you can normally paint a large number of cells by moving the mouse while the mouse button is held down. But if there is no mousedown event, then the program can't tell that the mouse button is down. Thus, IE users who want to be able to paint a lot of cells will have to pause long enough between clicks to ensure that the browser doesn't think it was a double-click. The right mouse button doesn't have this problem.

If you disable ActiveX in Internet Explorer, then you will not be able to save games or ratings.

Web paint-by-number will not work with IE version 5 or with any Macintosh version of IE.

Safari, Chrome, Konqueror, and iCab

Apple's Safari browser versions 1.2 and later work pretty well with web paint-by-number, as do all the other browsers based on the webKit rendering engine.

The only slight annoyance is that after you use a keyboard shortcut, the mouse cursor may vanish for a few seconds. In older versions control-clicks do not work (you can use alt-click instead) and the mouse cursor may turn into a text cursor while dragging. I found versions of Safari before 1.3.2 rather slow, but newer releases are very quick.

Some recent Safari versions have bugs in their regular expression code, which required me to write a whole different error checker and helper program to work around. But with the workarounds in place, they work just fine.

Google's Chrome browser uses the same rendering engine that Safari does (but a different Javascript interpreter), so all versions work fine.

I've tested only a few versions of Konqueror, the browser Safari is based on. It seems a bit slow, especially in loading the puzzles, but generally works. While loading big boards, version 3.4.2 may pop up a message saying a script has caused it to freeze and asking if you want to abort. Don't abort. Tell it to continue. The board will eventually finish drawing.

Starting with version 4, iCab uses the same rendering engine as Safari, and presumably works as well as Safari. Older versions of iCab were somewhat flakey and sometimes crashed on webpbn puzzles.


I haven't actually noticed any major problems using Opera versions 10.50 and later on webpbn. The only problem that remain are that you can't use the middle mouse button.

In versions before 9.50, the right button was also unusable. Versions as late as 9.0 had bugs in their regular expression evalution, but webpbn now avoids using regular expressions in Opera, so those should no longer be a problem.

Versions of Opera before 8.0 will not fully work with the current version of Web Paint-by-Number, as they do not support the XMLHttpRequest method used to save puzzles and ratings.