MacMost Now 452: Browser Cookies

Your web browser uses to store bits of information associated with the web sites you visit. There are misconceptions about what cookies do and how they are used. Learn how to examine your browser cookies and set your cookie storage preferences.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: MacMost Now 452: Browser Cookies.

Hi. This is Gary with MacMost Now. On today's episode, let's take a look at browser cookies.
So occasionally, I get asked about cookies. It seems like a lot of people don't know exactly what they are, and there are some misconceptions. So let's take a closer look.
So a web cookie, or browser cookie is a bit of information stored on your computer, associated with the web site that you're currently visiting. So a classic example is a weather website. The first time you go to the website, it may ask you where you live, and then shows you your local weather. But it stores that bit of information on your computer, and the next time you visit the website, instead of asking where you live, it simply retrieves that bit of information from your computer, and it already knows what weather to show you.
Now it's your computer and your browser that controls this information. So for instance, this weather site can only get bits of information that are associated with that weather site. It cannot get bits of information stored from other websites. So you go to a second weather website, and it has no idea what location you're in, because it doesn't have access to that information. Your browser and your computer is not going to send it to the second website.
So here we are in Safari. To view your browser cookies, just go to Safari preferences, and under there, click on "security," and then click "show cookies." This brings up a list of all the cookies that your browser is currently storing. Again, these are things that are stored on your computer. You can look through them and see the website and also the name of the cookie, and contents.
So, a lot of this won't mean much unless you are a programmer. So let's say we start here with no cookies at all stored. We're going to go to a website, a weather one. When we go there, we can see some cookies have been added by that website. Now, none of these seem to give us any information, and they're probably telling us things like that we visited the website for the first time, and so we're not a new visitor to it. If we go and type in a zip code here, it will give us the weather for that zip code. Now when we go back to preferences, we notice there's a new one here, named RC. And when we look here, we can see there's the zip code built into it.
So there are a lot of misconceptions around cookies. For instance, some people think they're used by spammers, other people think they're parts of viruses or malware. People think that they are used to generate browser pop-ups, and others think that they're only used for advertising. That's all not true. Most popular websites, like Google, Yahoo, news websites,, all use browser cookies to enhance the user experience.
What they are used for is to manage sessions, and also to remember your preferences. So for instance, if you go to a shopping website and you tell the site what sort of clothing you're looking for or what sizes you are, what colors you like, things like that, it may remember them and give you suggestions at future times. It also may look at your progress through the site, remembering things like items in your shopping cart and other preferences for going through the store. And some sites use it for other things. For instance, my site uses it to store games, so you could actually be in the middle of a solitaire game, leave the website and return, and your cards will be just where you left them.
Now there is an interesting case of third party cookies. So when you go to a website, you may not just be at that website. For instance, there may be a YouTube video embedded in that website. There may be an advertisement served by another company. Now there may be images that are also served from another company. So there could be cookies stored not just by the website you're visiting, but by content used on other servers. So for instance, an advertiser may actually see that you're at a webpage about shoes, and may then remember that and show you an ad about shoes even when you're shopping at another site.
You have control over this in Safari preferences, under security. You can set it to accept cookies 'always,' 'never,' or 'only from sites you visit,' which means that third party cookies will not be saved, only cookies from the actual website that you're on will be saved in your browser. I recommend having your browser set to always accept cookies, or only for websites that you visit. Having it set to never means that many websites may not work, and others will be severely crippled. Even having it set to 'only for websites you visit' could hamper a lot of websites, as they rely on multiple servers to put all the content up on the screen.
So there's a look at cookies, for those of you who were wondering.
Until next time, this is Gary with MacMost Now.

Comments: 10 Responses to “MacMost Now 452: Browser Cookies”

    9 years ago

    Hi Garry
    Thanks for your clarification on browser cookies.
    When it comes to browsers, I just wanted to share another interesting finding in my safari window that appeared since the latest update; that is when you start typing in the search bar, you’ll notice that a helping menu pops open, and you get prompted to chose from 3 different search engines.
    So good news to all safari users is that we’re no longer stuck with google; now you can freely choose yahoo or bing…

    9 years ago

    Thanks for the explanations, which were helpful.

    But not all cookies are so benign. I was once checking fares on some budget airlines and found that after several visits to check a particular route and time, the quoted fare went up sharply. After I had removed the airline cookies from my computer, I was once again offered the previous, competitive fare.

      9 years ago

      That’s interesting, but it is a completely different thing than being dangerous to your computer or your privacy. Also, if it was the intent of the site to do this (why?) they could also do it without cookies easily enough.

    Norman Medina
    9 years ago and are sharing information. Is the information shared through cookies? Or is is it done through IP address? Is there a way to sever this communication between facebook and other websites?

      9 years ago

      Hard to tell. But they probably say so in their privacy policies. They can’t share information between domains using cookies. But they can if you allow third-party cookies (see video) and they put each other’s content on each other’s sites (a widget from CNN appears on FaceBook, for instance).
      What makes you think they share info and what is your concern?

    9 years ago

    Actually cookies are not so benign if you value the
    last vestiges of your privacy. Example: Try flushing
    all your cookies then select “NO” to accept cookies.
    If your hidden files option is on you will see that
    google sets cookies with no problems but it’s hidden
    from you on your own computer. If you think this is
    benign just wait a few years. Cable TV or “pay” TV
    was ad free years ago, it was one of the rationales
    for paying for content. However, little by little ads
    crept in until we now see just as many ads on cable
    that we pay for. In the same way Google and other
    corporations tell us it is for our “shopping convenience”
    or more efficient browsing but that’s just the foot in the
    door. Resistance is futile…

      9 years ago

      I’m not sure I see your point. There are already ads on sites. Ads pay for “free” content. How is that affecting privacy?

        9 years ago

        Essentially I am asking why Google sets hidden cookies on computers.
        I thought that was clear. Once you lose control over cookies, what’s next?

        The point being snooping is getting incrementally more aggressive every year. The ads on cable TV were not in reference to ads but how the public is slowly acclimated to loss of privacy (or ads) as well as being told it is for their own convenience.

          9 years ago

          Hidden cookies? Cookies aren’t hidden, though. Google actually has a whole dashboard set up where they list all of the data associated with your account. Pretty transparent.

    Mr Anthony Cotton
    8 years ago

    Yes i can understand about the cookies being hidden. I recently had an upgrade and when i went to have a look at the cookies i could not see them. This word next to the cookies window says Details,click on Details,and then it shows all of your cookies. Anthony

Comments Closed.