What Is Cloudinary? Why Slim Minima Uses It

When you upload a photo to a Slim Minima site, it does not sit on the same server as your pages. It goes to Cloudinary, a service whose entire job is to store images and files, optimize them, and deliver them fast to every visitor.

The first thing worth saying is that Cloudinary is the one part of the default stack a site can technically run without. Without it, all your pages, posts, menus, and text still work perfectly. You just cannot upload or serve new media. For any site with images, which is almost all of them, it is the recommended default and worth setting up from the start.

This article explains what Cloudinary does, how a Slim Minima site uses it, why it is the default, and the one setting people forget that quietly breaks PDF downloads. Figures came from Cloudinary's official pricing and documentation, checked in June 2026.

What Cloudinary actually does

Cloudinary handles three jobs that, done badly, make a site slow and heavy.

It stores your media. Every image and file you upload lives in your Cloudinary account, not in your database and not on your web host.
It delivers from a global network. Images load from a server near each visitor, so they arrive quickly whether someone is in Sydney or Toronto.
It optimizes on the fly. This is the part that matters most. Cloudinary resizes images to fit the space they appear in, converts them to modern lightweight formats like WebP or AVIF when the visitor's browser supports them, and compresses them to a sensible quality automatically.

That last point has a real effect. A hero photo you upload at 500 KB might be delivered to a phone at 80 KB, looking the same to the eye but loading several times faster. You do nothing to make this happen. The site requests the optimized version through the image URL, and Cloudinary produces it.

Cloudinary also stores and serves non-image files like PDFs and ZIP archives, which is how a Slim Minima site can offer a downloadable brochure or price list.

How Cloudinary works with Slim Minima

Connecting Cloudinary is a three-value setup, and you can do it without touching code.

Sign up for a free Cloudinary account.
Copy three values from the dashboard: your cloud name, your API key, and your API secret.
Put them into the site, either as environment variables or directly in the admin panel under Settings, in the media storage section.

Once those three values are set, the media library in the admin panel comes alive. When you upload an image, it goes straight from your browser to Cloudinary using a short-lived signed permission, so large files never have to pass through your own server. New uploads land in a folder, named slim-minima by default, which keeps one account tidy even if you run more than one site from it.

Deleting media is handled carefully. When you remove an image, it goes to a media trash rather than vanishing, and a daily cleanup job permanently removes anything that has been in the trash past a set number of days, 30 by default. This is worth knowing because of one edge case: if you permanently delete an image and later restore an old version of a page that used it, that spot will show a broken image, since the file is genuinely gone.

Removing an image from a page does not delete it from your library, so this only happens after a permanent delete.

Like the rest of the stack, Cloudinary is swappable. The media layer can be pointed at Amazon S3, Cloudflare R2, or your own storage instead. Cloudinary is the default because it does the optimization and delivery work for you, for free, at the scale a marketing site needs.

Why we recommend Cloudinary

The optimization is automatic and it helps SEO. Faster-loading images improve the page experience that search engines measure, with no manual exporting or resizing on your part.
The free tier is real. A small site's images fit comfortably inside it, with no credit card to start.
Uploads do not burden your server. Files go directly from the browser to Cloudinary, so your host stays light and the admin panel feels quick even with large photos.
One account, many sites. Folders keep media separate, so an agency can run several client sites from a single Cloudinary account if it wants to.
It handles files, not just photos. PDFs and ZIPs work too, once you flip the setting below.

The setting almost everyone forgets

Here is the one that wastes an afternoon if you do not know it. Cloudinary blocks the delivery of PDF and ZIP files by default.

You can upload a PDF, see it in your media library, link to it, and then watch it return an error when a visitor clicks the link. Nothing in your site is broken. Cloudinary is simply refusing to serve that file type until you allow it.

The fix takes ten seconds. In the Cloudinary console, open Settings, go to the Security section, and tick the option to allow delivery of PDF and ZIP files. After that, downloads work. If you plan to offer any document on your site, do this before you go live so you never see the broken link in the first place.

Understanding the free tier

Cloudinary's free plan does not work in plain gigabytes. It works in credits, and understanding that saves confusion later.

The free plan gives you 25 credits per month, and one credit buys any one of these:

1 GB of stored media, or
1 GB of delivery to visitors, or
1,000 image transformations

You split those 25 credits across whatever your site actually uses. A site that stores a lot of images but gets modest traffic spends most credits on storage. A busier site with fewer images spends more on delivery. The flexibility is the point, but it means there is no single "you get X gigabytes" number, which is why some write-ups get it wrong.

For a typical marketing site, 25 credits is plenty. The deeper math on how that maps to real traffic, next to Vercel and Neon, is in how far the free stack stretches. The free plan needs no credit card. The next tier up, Plus, is 99 US dollars a month and only becomes relevant for image-heavy sites with serious traffic.

When you would upgrade

Stay on the free plan until one of these is consistently true:

Your stored media plus monthly delivery genuinely exceeds the 25-credit pool.
You run a media-heavy or video-heavy site that pushes a lot of data every month.
You need more team members on the account than the free plan allows.

Most small sites never reach that point. If you do, you upgrade Cloudinary on its own, independent of your hosting or database, so you only pay for the part that grew.

Frequently asked questions

Is Cloudinary free? Yes, there is a free plan with no credit card required. It gives 25 credits a month, where one credit covers 1 GB of storage, 1 GB of delivery, or 1,000 image transformations, split however your site uses them. A small marketing site fits comfortably inside it.

Can a Slim Minima site run without Cloudinary? The site itself runs fine without it. Pages, posts, menus, and all your text work normally. What you lose is the ability to upload and serve media, so for any site with images, Cloudinary is the recommended default to set up from the start.

Why are my PDF downloads showing an error? Cloudinary blocks PDF and ZIP delivery by default. Open the Cloudinary console, go to Settings, then Security, and tick the option to allow delivery of PDF and ZIP files. The downloads will work straight after.

Do my images get optimized automatically? Yes. Cloudinary resizes images to the space they appear in, converts them to lightweight formats like WebP or AVIF when the browser supports them, and compresses them to a sensible quality. A 500 KB upload is often delivered at well under 100 KB, which loads faster and helps your page experience scores.

What happens to an old page version if I permanently delete its image? The restored version will show a broken image in that spot, because the file is genuinely gone from Cloudinary. Removing an image from a page does not delete it from your library, so this only happens after you permanently delete the file from the media trash.

Can I use my own storage instead of Cloudinary? Yes. The media layer can be pointed at Amazon S3, Cloudflare R2, or your own server. Cloudinary is the default because it handles delivery and optimization for free, but it is not a requirement.

My verdict

Cloudinary earns its place because it turns image handling, normally a fiddly chore, into something you never think about. Upload a photo, get a fast optimized version everywhere, for free at the scale a small site needs. Set it up from the start, flip the PDF setting before launch, and it quietly does its job for the life of the site.

What Is Cloudinary? And Why Slim Minima Uses It for Media