83 votes
Accepted

How do I open the JavaScript console in different browsers?

Chrome Opening the “Console” panel of Chrome’s DevTools: Windows and Linux: Ctrl + Shift + J Mac OS: Cmd + Opt + J Note: In addition to the “Console” panel, there also exists a smaller slide-up ...
55 votes

Why don't browsers have jQuery installed?

If you serve jQuery from a popular CDN such as Google's Hosted Libraries or cdnjs, it won't be redownloaded if your visitor has been on a site that referenced it from the same source (as long as the ...
  • 20.4k
22 votes
Accepted

Why do browsers know to lookup the `www` record if DNS query for @ gets NXDOMAIN?

Browsers generally have heuristics built in to add missing www. from domain names, but it isn't something you should rely on: Browsers typically have a setting to turn off this "www fix up."...
21 votes

Why don't browsers have jQuery installed?

Not only is jQuery not the only popular JS library, a browser would potentially have to include multiple versions. The Google CDN currently lists: 42 versions of jQuery; 44 versions of jQuery UI; 6 ...
  • 5,814
14 votes
Accepted

Why does the internet think Microsoft Edge is Google Chrome?

Because Microsoft Edge presents a User-Agent string that contains the word Chrome. And, for that matter, Safari. Check out http://whatsmyuseragent.com/ and you'll see something like this: (Emphasis ...
14 votes

Why don't browsers have jQuery installed?

The browser is the engine it isn't the engine designer's duty to find out what kind of fuel and extra parts are you going to put into your car and include it for you. If they would do this browsers ...
  • 296
14 votes

How can I see what filename my browser is reading when it's on a site?

The browser isn't looking for a file. It's just asking for a resource. The server then decides what that resource returns. At it's most basic level that "file" is literally just a file. In the case ...
  • 85.9k
14 votes
Accepted

How can I see what filename my browser is reading when it's on a site?

Your browsers doesn't load any file, it requests a resource which the server then provides at his discretion (lengthy elaboration below). If you type google.com into your browsers toolbar, the ...
  • 257
9 votes

When using a stacked font-family, what does the browser use when NONE of the specified fonts are present?

It will not use the browser default font. But rather it will use the default sans-serif font. Since the last font in the font stack is not a specific font. It is a generic name. Some browsers allow ...
  • 91
9 votes
Accepted

Prevent browser from caching text file

You have two approaches to this problem. The clean way is to set the headers returned for GET data.txt preventing the browser (or proxy) from storing the response in cache. Using apache, this can ...
7 votes

Is it possible to stop Chrome and other browsers from pre-fetching/rendering my site?

Google Chrome does not send any special headers to prerender requests anymore. See: https://code.google.com/p/chromium/issues/detail?id=86175 https://github.com/nickhsharp/prefetchNightmare
  • 171
7 votes

Using multiple A-records for my domain - do web browsers ever try more than one?

Be warned that Windows Vista implements the stupid parts of RFC3484 (i.e. the backporting from IPV6 to IPV4) and will prefer the IP address that shares most prefix bits with the user's IP address ...
  • 2,231
7 votes
Accepted

Prevent form resubmit after Browser Back button click

One way to prevent this is to use the POST/Redirect/GET pattern. Instead of directly sending a 200 after receiving the POST request, the server sends a 303 (or 302) redirect instead. The client ...
  • 21.5k
6 votes

Can I omit the domain name for href in the HTML base tag?

No. The href must point to an absolute URI. Relative is not allowed on a base element. This attribute specifies an absolute URI that acts as the base URI for resolving relative URIs. The HTML5 ...
  • 4,608
5 votes
Accepted

XSRF Error when link is opened via an <a> tag with target attribute set to "_blank"

In my testing, Firefox 41 and Chrome 45 are affected; IE 11 and Safari 8 are not. I have not tested other versions of these browsers. Apparently, when one page opens another in a new window/tab, they ...
  • 166
5 votes

Are resized browser windows a real-world use case?

Users almost never resize a window while using your site. It is often possible for the resizing itself to cause problems. This is especially the case when you use JavaScript to calculate and set ...
4 votes

Pages that never finish loading: How to diagnose

You should do the following to get an exact reason why your page never finishes loading: Do you call any 3rd party scripts on your page? If yes, then check if they respond properly. Check your ...
4 votes

When using a stacked font-family, what does the browser use when NONE of the specified fonts are present?

It will resort to the default font of the browser. In this case with the sans-serif specification it would look for the default sans-serif font. I think for Windows this font is Arial, and for Mac it'...
4 votes

How can I see what filename my browser is reading when it's on a site?

I'm wondering how I know what file is being rendered. I can eventually guess it accurately on a long enough timeline by simply explicitly calling on that filename in the URL. www.xyz.com/index.html ...
4 votes

How to decide which browsers to support?

The objective measure is in money: How much does it cost to maintain the browser support vs how much it costs to turn away users because of browser compatibility. Costs of turning away users ...
4 votes

How can I protect my users' privacy when social share buttons may be pre-fetched?

The buttons themselves don't need to be loaded from the social site at all. For example, both Facebook and Twitter let you simply open a window with a special URL, which shows a "New post" window with ...
  • 304
4 votes
Accepted

DOMContentLoaded vs. 'load' event vs. "Finish"

Many web pages that make requests using JS are never really fully loaded, because they can always request more assets seconds, minutes or even hours later, either to update the page (think like Gmail) ...
4 votes

Browser seems to automatically add 'nofollow' to links, even though it's not in the page source

As this is happening across all browsers I'd say it's unlikely a browser extension is doing this. Although still check if it happens with any turned off. Failing that, it may be that the site is ...
  • 6,077
3 votes
Accepted

How much recyling CSS makes my website faster?

The only part of that, where the browser would work harder, is having to parse the extra few characters for each selector. Insignificantly so because the majority of the work is done on creating a CSS ...
  • 4,608
3 votes

Why is my site getting requests for URLs converted to lowercase?

These are usually hits from bad bots. Unfortunately, it is very common for bots to attempt to lowercase the entire URL. I have a website with mixed case URLs. I get thousands of hits per day for ...
3 votes

Google Analytics: how to consolidate browser counts by major version number?

This is not currently possible within Google Analytics, but only takes a few short steps to do in excel. In GA, go to Audience > Technology > Browser & OS. Set the secondary dimension to "...
  • 686
3 votes

Do Google and others care how much CPU/GPU is used by the web browser to render a webpage?

Crawlers don't necessarily take into account CPU but page loading time is a factor that is taken into consideration. If your page takes too long to respond then it will not be indexed and it will have ...
3 votes
Accepted

robots meta tag for specific web crawler

<meta name="robots" content="index, follow"> <meta name="googlebot" content="index, follow, noimageindex"> Yes, this will "work" as ...
  • 41.8k
3 votes
Accepted

Why do browsers only display .jpg images and never .jpeg ones?

Thia is likely due to the way the CDN is set up. When an object is sent by the web server, the server typically asvisises the "mime type" - a string advising the kind of object - to the ...
  • 6,208
3 votes
Accepted

Recent Samsung Internet browser update is blocking cookies for "log in" and "add to basket" on my site

Smart Anti Tracking has to be disabled on my Samsung galaxy s10e to make Samsung Internet usable for some standard websites such as BBC. Completely unusable otherwise. I'm surprised there's not more ...

Only top scored, non community-wiki answers of a minimum length are eligible