CDN
Purging the Kapsule CDN Cache
Purging clears the copy of your content held at the edge so the next visitor gets a freshly fetched version from your origin, which is what you do when you have published a change and the old version is still showing.
Caching is what makes the CDN fast, and it is also the reason a change you just made may not appear straight away. Rather than dropping your cache lifetimes to nothing, keep them long and purge on demand. This guide covers both, plus how to tell an edge cache from a browser cache before you go looking in the wrong place.
When You Need to Purge
Purge after you have changed something that visitors fetch by URL:
- You replaced a CSS or JavaScript file and the old one is still being served.
- You uploaded a new version of an image over the top of an existing filename.
- You fixed a bug on a page and want the broken version gone globally, right now.
- You changed a page's content and cannot wait for the edge TTL to expire.
You do not need to purge when you have added a brand new page or a new filename. Nothing is cached for a URL that has never been requested.
If you version your asset filenames (style.a1b2c3.css rather than style.css), you rarely need to purge at all. A new filename is a new URL, so it is fetched fresh from your origin and cached under its own key.
Where the Purge Control Lives
- Sign in to KPanel.
- Click Websites in the left sidebar, then click your site.
- In the site's menu, open Performance, then Kapsule CDN.
- Scroll to the Purge cache card.
The direct address is /websites/<site-id>/cdn.
The purge control only appears once the CDN is switched on for the site. If the page shows the banner CDN is off for this site, or asks you to connect a custom domain, there is nothing at the edge to purge yet. Kapsule CDN is also a plan entitlement, so a site on an Orbit or Container Hosting plan has no CDN at all. Enabling Kapsule CDN on Your Site lists exactly which plans include it.
Purging a Single URL
- In the Purge cache card, type the full public URL into URL to purge (leave blank for whole site). The field's placeholder shows the expected shape:
https://your-domain.tld/path. - Click Purge.
- A confirmation appears reading "Purged" followed by the URL you entered.
Use the exact URL a visitor would request, including the scheme (https://), the host, and the path. A purge is matched on the URL, so https://example.com/about and https://example.com/about/ are two different cache entries, and so is the same page with a query string attached.
Purging one URL is the right first move when you know exactly what changed. It is instant and it leaves the rest of your cache intact, so the rest of the site stays fast.
Purging the Whole Site
- Leave the URL to purge field completely blank.
- Click Purge.
- The confirmation reads "Full cache purged."
A full purge empties every cached object for the site at every edge location. Until each URL is requested again, every visitor is served from your origin, so the origin takes a burst of traffic and the first visitor to each page waits for a full round trip. On a busy site, prefer purging the specific URLs you changed.
Every purge you run is recorded in the account's activity log with the URL or a full-zone marker, so you can see who purged what and when.
Cache Lifetimes and How They Interact
The Cache TTLs card, on the same page, controls how long content survives without a purge:
| Setting | What it controls | Default |
|---|---|---|
| Edge TTL (seconds) | How long the edge holds a copy before re-fetching from your origin | 3600 (1 hour) |
| Browser TTL (seconds) | How long a visitor's browser keeps its own local copy | 3600 (1 hour) |
The two are independent, and this is the single most common source of confusion. A purge clears the edge. It cannot reach into a visitor's browser. If you purge and still see the old version yourself, you are almost certainly looking at your own browser cache.
To rule that out, load the page in a private or incognito window, or do a hard reload. If the private window shows the new version, the purge worked and you are only waiting on your own browser and on other visitors' browsers, which will refresh once their browser TTL expires.
If you publish frequently and cannot version filenames, drop the Browser TTL to something short (a few minutes) and leave the Edge TTL long. You keep most of the edge benefit while giving visitors a much shorter window in which they can be stuck on an old copy.
Image Optimisation and Purging
If On-the-fly image optimisation is on, the edge stores the optimised derivative of each image alongside the original. Purging the image URL clears the derivative too, so a replaced image is re-optimised on its next request. There is no separate purge for optimised images.
The same applies to Serve WebP to supported browsers: the WebP variant lives under the same URL and is cleared by the same purge.
Troubleshooting
"CDN not provisioned for this site." The site has no edge zone yet. Enable the CDN first, and wait for the certificate to finish provisioning.
"Purge failed." The purge request did not reach the edge. Wait a moment and try again. If it keeps failing, the edge zone may be mid-provision; check that the page shows the CDN is on banner.
I purged and the page is still old. Check in a private window first. If a private window also shows the old version, confirm you purged the exact URL, including any trailing slash and query string, then try a full purge.
Only some visitors see the update. Their browsers are still inside the browser TTL. Nothing is wrong: they will pick up the new version when that expires, or immediately on a hard reload.
The origin fell over after a full purge. That is the burst of uncached traffic described above. Raise the edge TTL, and next time purge only the URLs that changed. Improving Website Speed covers making the origin itself more resilient.
If a purge succeeds but the edge keeps serving old content for more than a few minutes, email support@kapsulehost.com with the exact URL and the time you purged.