How-To Geek

6 Types of Browser Errors While Loading Web Pages and What They Mean


You’re guaranteed to stumble into an occasional error page while browsing the web. This guide will help you understand exactly what each erro page means and what to do when you see them.

Note that each browser displays and words its error pages differently. A certificate error or malware warning looks different in each different browser, but the different types of error pages mean the same thing.

Certificate Error

An SSL certificate error or security certificate error indicates a problem with HTTPS encryption. You’ll only see this error when connecting to a website using HTTPS.

When using HTTPS encryption, websites present certificates to identify that they are legitimate. For example, has a security certificate issued by a trusted certificate authority. The certificate authority verifies that Google is the real owner of and is entitled to the certificate. When you connect to using HTTPS, Google presents this certificate. Your browser checks that the certificate was issued by a known legitimate certificate authority to verify you’re connecting to the real, not another server pretending to be

When you see a certificate error, this indicates that you’re not necessarily connecting to the real, legitimate website. For example, if you try to access your bank’s website on a public Wi-Fi network and see this error, it’s possible that the network is compromised and someone is attempting to impersonate your bank’s website.

However, it’s also possible that a website failed to properly renew or configure its certificate. Either way, you shouldn’t continue when you see this error message.


Phishing and Malware Warnings

Your browser will also display phishing (or “web forgery”) and malware warnings. Whether you use Firefox, Chrome, or Internet Explorer, your browser regularly downloads a list of dangerous websites. When you attempt to connect to a website on this list, you’ll see an error message.

Websites are placed on these lists because they contain malware or because they attempt to impersonate a real website to steal your passwords, credit card numbers, or other sensitive information.

In some cases, a website may temporarily be added to this list because it was compromised. When the website is fixed, it should be removed from this list. When you see this message, you shouldn’t continue.


404 Not Found

You may see a variety of web server messages when accessing web pages. The most common one is “404 Not Found,” which means you’re trying to access a page that doesn’t exist. Either the web page was removed or you were typing in an address and mistyped it.

These error messages are generated by the remote web server and sent to your browser. If you see these, double-check the web page address you typed. If you clicked a link, the link was in error – or the page it points to has been removed.


Customized Error Pages

Website owners can customize the 404 Not Found and other error pages on their websites. For example, here at How-To Geek, we have a special 404 Page Not Found error inspired by classic Mario games. These errors mean the same thing, but they’re generally customized to be more friendly and help you find what you’re looking for.


Server Not Found

A “Server not found” error in Firefox or “Google Chrome could not find []” message indicates that your browser could not find the website you’re trying to access.

Either you mistyped a website address and you’re trying to access a website that doesn’t exist, your DNS server is down, or your firewall, proxy, or other settings are misconfigured.


Unable to Connect

The “Unable to connect” error in Firefox or “Google Chrome could not connect to []” message looks similar to the “Server not found” message above, but each means something different.

if you see this message, your browser has successfully contacted its DNS servers and identified that there should be a website at the target location. However, your browser did not receive a response from the website’s servers when it tried to connect.

If you see this message, it’s possible that the website itself is down or experiencing problems. You may want to try Down For Everyone Or Just For Me, a website which tells you whether a website is down or if you just can’t access it. It’s also possible that your firewall, proxy, or other network settings are misconfigured.

Read More: How To Troubleshoot Internet Connection Problems


There are quite a few other errors you may come across, but these are the most common ones. With some knowledge of these errors, you should know what’s going on every time you bump into an error page on the web.

Chris Hoffman is a technology writer and all-around computer geek. He's as at home using the Linux terminal as he is digging into the Windows registry. Connect with him on Google+.

  • Published 01/13/13

Comments (14)

  1. Srivatsan Venkatesh

    Blizzard’s 404 page is hilarious. The homepages is like a cracked screen and tilted on its side.

  2. krokkenoster

    Thank you for the info Dummies like me become the suckers but I learn daily

  3. Saigon

    I feel proud that I know all this already.

  4. jrau

    Raise your hand if you tried to click the “Try Again” buttons.

  5. Ushindi

    I would STILL like to know where I could find the “other castle” for your article “Propaganda Posters For A Modern Age”, as Jason F. never seems to read the comments when something he posts doesn’t work. Could someone fix the link? It would certainly be appreciated by others as well as myself.

  6. bedlamb

    2 Ushindi
    He was being facetious. There is no other ‘castle’.

  7. Peter

    @ Srivatsan … have you got a 404 error page for Blizzard? I’d love to see it.

  8. George
  9. ned11wils

    @Saigon. Prove it! :)

  10. Jim

    I’ll throw in some details about 404 -File Not Found…

    By default, if a web server does not find the page (or file) a visitor’s browser asked for, the server returns just the 404 error number. The folks who wrote each browser determined what the error message will look like on your screen. Many ISP’s will trap the error and show you their OWN page, with thier OWN advertising or ther OWN “search engine” showing your links they get paid for.

    However, most web sites can be set up to detect that the file name is invalid internally and instead of returning a 404 error, it returns their own default html error page as shown in the HowToGeek and Blizzard examples. I’ve also seen sites where an internal file not found just gives visitors the front page. Either case is a whole lot better for the intended web site than a 404 error screen from the browser. Long URL’s frequently get mashed or truncated in email notes, so a default 404 page at least keeps the visitors on your site.

  11. Gregg DesElms

    “Web forgery?”

    Not just calling it “phishing” (or at least including that word somewhere on the page to indicate that that’s what a “web forgery” is) just confuses users who’ve heard the word “phishing,” but who haven’t a clue what is a “web forgery.”

    Geez. Don’t fix it if it ain’t broke.

    Gregg L. DesElms
    Napa, California USA
    gregg at greggdeselms dot com

  12. Ushindi

    My point was – Jason F. put up a link in his article that didn’t work but did nothing to fix it. Somewhere, in “another castle” (I KNOW there is no actual castle!) is the correct link, and that is what I was asking for.
    In my experience here, other contributors to HTG seem to fix their work when there’s a problem, but not him. Not picking on him, but I wish he would check his work occasionally.

  13. Culinary Muse

    What about the one “He’s dead, Jim” when I shut down a bunch of windows improperly? Where did that come from and what does it mean?

  14. Ushindi

    @Culinary Muse:
    Re Chrome: “You may see the “He’s Dead, Jim!” message if the operating system has terminated the tab’s process due to a lack of memory. Computers rely on memory to run programs. Low amounts of memory can cause programs to run slowly or stop running altogether.

    Alternatively, if you terminated the process using Google Chrome’s Task Manager, the system’s task manager, or with a command line tool, this message will appear as well.”

    “Curious about the title? “He’s dead, Jim!” is a reference from Star Trek to describe things that are unresponsive.”

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