What Does “Purge Cache” Mean? Will it Delete My Blog??

Okay I am fairly new to WordPress. I am also computer dumb when it comes to tech talk. On my “Posts” page in my dashboard, it has “Purge from cache”. What exactly is this and what does it mean? If I happen to accidentally click on it, will it delete the whole post or my blog? No laughing!
Confused in WP world

It sounds like you’re using a caching plugin. So before I talk about “Purge Cache”, I’ll talk a bit about what a caching plugin even does.

How do caching plugins work?

If you’re using one, it’s probably because you’ve heard people say, “You need a caching plugin because it will make your site load faster!” But have you ever wondered why that’s the case?

WordPress sites are dynamic. That means they use a database, have complicated PHP scripts, and they’re always changing. All of your posts, comments, and other information are stored in this database. And every time you load the page, your blog has to figure out what page (or post) you’re trying to view, then pull that content out of the database to display it for you. It does that on every single page load. That’s a lot of work!

What a caching plugin does (usually) is generate static, HTML copies of your pages. So when the page gets viewed, it saves a copy of that page in a static form, the it displays that static HTML copy to your users. That way it doesn’t have to check the database every single time. It saves time and resources when loading pages. This can be why sometimes you make a change to one of your posts and you don’t see the changes instantly; it means you’re still viewing the old “copy” instead of a live version that gets retrieved from the database on the fly.

Still confused? Let’s use a metaphor! WOOHOO!

Say there’s an author of a book. That author has a finished, complete copy of the book. Now let’s say someone has decided to read that book in ebook format. In our metaphorical example, every time the reader turns the page, the author has to look up that page of the book and send the page contents to the reader. Manually. And they have to do that every single time for every single reader. They’re constantly flipping pages to send the content to the reader.

Wow, that sucks. So let’s introduce caching:

The author is fed up so they decide that instead of manually sending the page content, they’re just going to create a ton of copies and send each reader one of those copies. Now the author doesn’t have to do any work, because each reader has his or her own copy and they can view that static content. But that means if the author makes any changes to the book, the readers may not get them right away because they’re reading copies of the original.

What does “purge cache” do?

So now let’s talk about purging the cache. That simply means to delete the HTML “copies” of your pages. So if you purge the cache, it means the next time you view your blog, it will generate the page by pulling info from the database (the original method). Then, it will recopy the page again to create a new, static HTML copy.

So let’s go back to our metaphor. Say the author fixes a few typos in the book. Since the readers have their copies, they aren’t going to get the updates (at least not immediately). So to speed the process along, the author purges the cache. That means the author deletes all the copies that the readers had before, and then sends them new copies that have the corrections!

Purging the cache will not delete your blog!

Most caching plugins are set up to purge the cache after a certain amount of time (like once a day or once every few hours, or may even once a week). But if you make an edit to one of your posts and find that you can’t see the changes immediately but want them to be available, that would be a good reason to manually purge the cache.

Recommended caching plugins

Want a caching plugin? See below for a few recommendations! But keep in mind that a few hosts do not allow their users to use caching plugins. Because while a caching plugin will make your blog load more quickly, it also uses more server resources, and some web hosts don’t like that! So be sure to check your web host’s terms of use before installing one.

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62 comments

  1. Forgive my naΓ―vetΓ©. Does this mean that every person would need to be clearing their caches as well, to get the most updated content? Or does clearing the cache on my end (through WP) remove their old content too?

    Kelly recently posted: Book Review: Angelfall
    1. This is only on your end, through the WP admin panel. *Browser* caching is different from the website itself actually doing the caching. But as I mentioned, most plugins are set to do this themselves periodically.

  2. Thank you Ashley for the common sense approach on “Purge from Cache” I have read other articles and it just talks nonsense, so what a breath of fresh air when you find a blog that does exactly what it says on the tin. Thank you again

  3. This is brilliant! Thank you so much. I’m trying to speed up my website and started to see that “do you want to purge” thing on my posts. I didn’t want to hit anything that I would regret later. So I guess I can just wait since my old updates that aren’t critical will update anyway when my cache plugin does. Thanks for explaining it so well!

    Zylo recently posted: April Dessert Recipes Round-Up
  4. Thanks for the valuable information. I am glad that i am no more tensed about my blocked website traffic and it’s again touching sky πŸ™‚ Thank you very much again

  5. Hey Ashley, it seems a little embarrassing, but I wouldn’t consider myself a novice with computers, however I was a little confused with what ‘purging the cache’ actually did. I really liked your down to Earth explanation that doesn’t ‘offend’ the reader with over simplification. Thanks again for clearing that up!

    Russell O'Neill recently posted: Live Your Dream
  6. Hi Ashley,

    This was an awesome explanation of “Purge Cache”!!!! I thank you very much for helping me understand.

    Thanking you,
    Troy

  7. I installed one of the plugins you mentioned and I was wondering what “purge cache” mean. Thanks for a wonderful explanation! It really helped me understand it.

  8. Finally found a great explanation on what Cache Purging is all about on WordPress. I do have the W3 Total Cache plugin installed. I was wondering if these plugins slow down your sites at all in loading for viewers?

    Robert recently posted: Mystery Island Vanuatu
    1. If configured incorrectly, it could potentially make your site slower, but the goal of a caching plugin is to make your site faster.

      The downside is that caching plugins use a lot of resources. So you might use more resources (CPU, RAM) with your web host, but your pages should load faster for viewers. But if you use too many resources, you could reach your limit, and if you do reach your limit then your site will load more slowly.

  9. Hi Ashley, I typed “what does purge cache mean?” in Google, and was lucky enough to click on your page. Thanks a million, Google’s page speed etc is driving me nuts. I wasn’t sure whether I should click on it too, now I know I can,

    Angela J recently posted: Website Content
  10. Thank you, thank you, thank you! Your author/reader metaphor made so much more sense. Although I’ve had a WP site for a while, I’ve done quite a bit of outsourcing. Now that I’m ready to take over myself, I’m finding it’s a lot like reading Latin while being dyslexic! Great post. Looking forward to others.

  11. Thank you for this blog post. Really helpful and easy to understand. I just pressed purge cache by mistake – had a meltdown with my site yesterday as buggered up the coding, so am a little touchy still. Your post has soothed my very frayed nerves. And great to see some girlpower out there too!

  12. really nice article, it really helped me! I had the same doubt of the meaning of “purging my cash”. To make it worst im brazilian so I had to look up the meaning of “purge”. Thanks a lot!

  13. Hello,
    Such a wonderful article. Easy to understand, helped a lot in understanding the core functionality of the cache plugin

    THank you.

    1. Ideally you should be able to set it up to purge automatically when publishing new posts/pages. If you can do that, you may never need to purge at all unless perhaps making theme/design edits.

  14. hello i am using CDN for loading fast to my ecommerce portal actually i am suffering from too slow load times that brings slow conversions and lost many traffic rate.
    while setting inside cloudflare cache called purge cache i was extremely unknown regarding this topic hen i studied about your blog and then i found about the article is working good thanks..

  15. thanks — very clear answer — and allows me to fully understand it. Great job.

  16. Thank you so much to clarify that, I was afraid of purge cache but after reading this, I did and no problem at all, thank you so much.

    Best Regards

  17. Thank you for this explanation! Sadly, I was one of those people who worried that “purging my cache” meant deleting my blog hahah kinda silly now that I think of it. The metaphor really helped with my understanding.

  18. I needed this and you managed to put it in simple terms without over simplifying! Thanks so much!

  19. One of the best articles I have read so far. And the best part I like about it that you have explained it in such a simple manner. Thank you for posting this article.

  20. I just started a 1 month old blog, at first I was confused and overwhelmed by all the information out there. But after stopping by this post, I know much more about the Cache thingy.

    Thank You

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