What is web cache, and what is it for?

When you visit a website and everything loads in seconds, it’s not always because your connection is super fast. Most of the time, the trick lies in something you don’t see: the web cache.

Let’s explain it without jargon. Because once you know how it works, you gain control over what you show, how your website looks, and how your brand feels in the digital world.

Definition of web cache

Web cache works like a fast memory that stores certain parts of a webpage so they don’t have to reload every time you visit.

For example, if you’ve already visited a website and return, chances are your browser won’t download the logo, style sheets, or scripts again. It simply uses what’s stored in the cache.

Is memory cache the same as web cache?

No. Memory cache can be any temporary storage on your computer or device. Web cache, however, refers specifically to resources used to load web pages.

How does web cache work?

Temporary storage of resources

When you first access a website, your browser stores some resources locally. Next time you return, it doesn’t need to fetch them from the server. It’s like having a shortcut to load everything faster.

Servers, browsers, and proxies

Three key players are involved here:

• Browsers like Chrome or Firefox store files locally.
• Servers can store processed versions of pages to avoid repeating tasks.
• Proxies or CDNs (like Cloudflare) distribute content on nearby servers to speed up global loading.

When is cache updated?

It depends. Some caches clear every time you close your browser. Others have a set time (e.g., 7 days). You can also force a manual update when you change something on your site.

Types of web cache

Browser cache

This is the most common. Your browser stores parts of a site so they don’t need to be downloaded again. This saves both time and data.

Server cache

This is where efficiency kicks in. At cdmon, for example, we use Varnish Cache, an advanced system that acts as an intermediary between the user and the server. What does it do?

• Stores processed pages.
• Reduces response time.
• Lightens server load.

That way, every time someone visits your site, the page isn’t generated from scratch: it’s instantly served from this cache.

Proxy or CDN cache

This system stores and distributes your content across multiple servers worldwide. The benefit? Your visitors connect to the closest server. That reduces latency and improves the overall experience.

Benefits of web cache

Let’s be clear: managing your cache well improves everything.

• Loading speed: your pages open faster.
• Resource savings: fewer server requests = lower consumption.
• Better user experience: nobody likes waiting.
• Positive SEO impact: Google notices and rewards it.

In short, performance improves without you or your visitors having to do a thing.

Drawbacks or issues with cache

Of course, it’s not perfect. Sometimes cache can cause headaches.

• Outdated content: the browser may keep showing an old version even after you’ve made changes.
• Update confusion: you modify something, but you (or your users) still see the old version.
• Need to clear it: if not managed well, cache can accumulate unnecessary files.

That’s why there are key moments when you should clear it.

When should you clear your web cache?

Don’t clear your cache without reason. But there are times when it’s almost mandatory:

• You’ve changed your website design or content and want everyone to see the updates.
• You notice display errors that don’t appear in another browser.

FAQs about web cache

Does cache take up much space?

It can build up several MB over time, especially if you visit lots of websites. But you can easily clear it in your browser settings.

Does it clear automatically?

Sometimes yes, but not always. There are set durations: an hour, a day, a week… You can also force an update if you change your website.

Does cache improve SEO?

Indirectly, yes. If your website loads faster thanks to cache, Google will take that into account. It also improves user experience, another key factor.

What’s the difference between cache and cookies?

• Cache stores resources to speed up loading.
• Cookies store user information, such as sessions or preferences.

Final thoughts

Controlling web cache gives you more sovereignty over how your site looks and works. It allows you to deliver a smoother, faster, and more professional experience to your visitors. And if you use hosting tools with advanced cache settings, like those from cdmon, even better.

From the browser to the server, cache can be your best ally… as long as you manage it responsibly.

Do you run a growing site or one with constant traffic? Then it’s no longer optional: cache is part of digital success.