One of the first decisions in any website project is whether to build on an open-source CMS or a SaaS platform. The open source vs SaaS CMS question shapes who owns your site, what it costs over time, who keeps it secure and how easily you can leave.
Neither model is better in every case. We build on both, and we recommend each regularly. This guide explains the real differences in plain terms, with examples of each, so you can decide which suits your organisation.
What the two models mean
An open-source CMS is software whose code is published under a licence that lets anyone use, change and host it. WordPress, Drupal, Joomla, Strapi, Payload and Ghost are common examples. You install it on hosting you choose and run it yourself, or pay someone to.
A SaaS CMS (software as a service) is a hosted product you subscribe to. The vendor runs the software, the servers and the updates. Webflow, Shopify, Squarespace, Wix, HubSpot CMS, Contentful and Storyblok all work this way.
The grey areas
Some platforms sit in between. Craft CMS and Statamic are self-hosted with code you can read and change, but they are commercial products. Their free editions are limited, and most business sites need a paid licence for features such as multiple editor accounts. Directus is source-available, free for smaller organisations and licensed above set thresholds. Several open-source products, such as WordPress, Ghost and Strapi, also have hosted versions you can pay for. And Sanity pairs an open-source editor with a hosted content store.
Ownership and control
With open source, you hold everything: the code, the database, the files and the hosting account. You can move host, change developer or rewrite any part of the system without anyone’s permission. That control is the main reason organisations choose it.
With SaaS, you own your content, but you rent the platform. The vendor decides the features, the limits, the pricing and the roadmap. If they remove a feature you rely on, raise prices or are bought by another company, you adapt. Most vendors are reasonable, but it is their platform, not yours.
Cost over time
The cost difference is less about the size of the bill and more about its shape.
Open source
The software is free, but the site is not. You pay for hosting, premium plugins or extensions, a maintenance plan and developer time for changes. Costs are uneven: a larger build up front, steady maintenance, then occasional bigger pieces of work such as major version upgrades.
SaaS
You pay a monthly or annual subscription that rises with traffic, seats, locales or features, often plus paid apps. The build can be quicker and cheaper, and maintenance is mostly included. But the subscription never stops, and price changes are outside your control.
Over three to five years, the totals are often closer than people expect. Our guide to CMS website cost breaks down what goes into each.
Compare platforms over five years, not on launch cost. Include hosting, licences, apps, maintenance and the developer time you will need for changes.
Security and maintenance
This is where SaaS has its clearest advantage. The vendor patches the software, runs the servers, handles traffic spikes and monitors for attacks. You still need good passwords, two-factor login and sensible user permissions, but the technical upkeep is not your job.
Open-source software is not less secure in itself. Popular platforms have security teams and release fixes quickly. The risk comes from sites that are not kept up to date. Old plugins, skipped updates and cheap hosting are behind most of the hacked sites we are asked to repair.
If you choose open source, budget for maintenance from day one:
- Regular core and plugin updates, tested on a staging copy first.
- Daily backups stored away from the main server.
- Security monitoring and a firewall.
- Good hosting with up-to-date server software.
- A plan for major upgrades, such as moving to a new major version before the old one reaches end of life.
That last point catches people out. Platforms retire old versions, and staying on them means no security fixes. Our article on Drupal 7 end of life options shows what that looks like in practice.
Lock-in and leaving
Every platform has some lock-in. The question is how much it would cost to leave.
With open source, you can always take the whole site, code and database, to another host or developer. Moving to a different CMS is still a project, but you are never forced off the platform.
With SaaS, you can export content, but usually not the design, templates or platform-specific features. Leaving often means rebuilding the front end. Some exports are good, such as structured JSON from headless platforms. Others are limited, especially for page-builder layouts. Ask how a full export works before you commit. Our CMS migration checklist covers what to plan for if you do move.
Flexibility and features
Open source gives you almost unlimited room to customise. If you need unusual integrations, complex permissions, custom data or a particular hosting setup, it can do it. The catch is that every custom piece needs building and maintaining.
SaaS platforms are more opinionated. What they do, they usually do well and with polish, but you work within their limits. Apps and integrations fill many gaps, though each one adds a subscription and another dependency.
Support and hiring
Popular open-source platforms have a large pool of developers and agencies, so you are rarely stuck if your current partner moves on. Niche platforms are harder to staff, which is worth weighing up before you commit.
SaaS platforms include vendor support, which is helpful for account and billing issues but rarely covers custom work. You will still want a developer or agency for design changes and integrations.
Open source vs SaaS CMS side by side
| Factor | Open source | SaaS |
|---|---|---|
| Ownership | You own code, data and hosting | You own content, rent the platform |
| Software cost | Free; pay for hosting and development | Ongoing subscription |
| Cost pattern | Larger build, steady maintenance, occasional upgrades | Lower build, recurring fees that rise with use |
| Security updates | Your responsibility | Handled by the vendor |
| Customisation | Almost unlimited | Within platform limits |
| Lock-in | Low, you can move host freely | Higher, front end usually rebuilt to leave |
| Examples | WordPress, Drupal, Joomla, Strapi, Payload, Ghost | Webflow, Shopify, Squarespace, Wix, HubSpot CMS, Contentful |
Which should you choose?
The open source vs SaaS CMS decision usually comes down to how much you want to own and how much support you will have.
Choose open source if:
- You need deep customisation, unusual integrations or full control of your data.
- You have a developer, in-house or on a maintenance plan, to keep it updated.
- Long-term independence from a single vendor matters to you.
- Your site is large or complex enough that subscriptions would become expensive.
Choose SaaS if:
- You want minimal technical upkeep and no servers to think about.
- Your needs fit what the platform does well, such as a marketing site or a standard online store.
- You would rather pay a predictable fee than manage maintenance.
- You do not have, and do not plan to have, ongoing developer support.
For a wider view of the decision, see how to choose the right CMS.
Frequently asked questions
Is open source CMS cheaper than SaaS?
The software is free, but hosting, maintenance and development are not. Over several years the totals are often similar, so compare full costs for your situation.
Is open source less secure than SaaS?
Not in itself. Well-maintained open-source sites are secure. The difference is that you are responsible for updates, while a SaaS vendor handles them for you.
Is WordPress open source or SaaS?
WordPress itself is open source and can be hosted anywhere. WordPress.com is a hosted service built on it, which works more like SaaS.
Is an open source or SaaS CMS better for SEO?
Both can rank well. Open source gives more control over technical SEO, while good SaaS platforms cover the basics. The content and how the site is built matter far more.
Can we switch from SaaS to open source later?
Yes. Content can usually be exported and imported, but the design and templates are normally rebuilt. Plan redirects carefully so you keep your search rankings.
Next steps
We build on open-source and SaaS platforms, so we can give you an honest view of which fits. Book a free consultation and we will recommend a platform and give you a fixed quote.
