Cloud-based vs on-premise library systems

What "cloud-based" means in practice

A cloud-based ILS is hosted by the vendor on their own infrastructure, and staff and patrons access it through a web browser from anywhere with an internet connection. The library doesn't need to own or maintain any server hardware. The vendor is responsible for backups, security patches, uptime, and rolling out new features — updates typically appear automatically, without any action from library staff. This model is usually sold as a subscription (a recurring fee per month or year), which is why it's often called SaaS, or Software as a Service.

What "on-premise" means in practice

An on-premise system is installed on a server the library owns, rents, or runs in a data centre it controls. The library (or a contracted IT provider) is responsible for maintaining that server, applying updates, running backups, and keeping it secure. Historically, this was often paired with a one-off perpetual licence fee rather than a subscription, though many vendors now offer on-premise systems on subscription terms too.

How they compare

Factor	Cloud-based (SaaS)	On-premise
Upfront cost	Low — usually no hardware to buy	Higher — server hardware and setup
Ongoing cost	Predictable subscription fee	Licence/maintenance plus hosting and IT time
IT effort required	Minimal — vendor manages the server	Ongoing — someone has to patch and maintain it
Access	Any device with a browser and internet	Often restricted to the local network, unless remote access is set up
Updates	Automatic, rolled out by the vendor	Scheduled and applied manually (or by IT support)
Data control	Data sits on the vendor's infrastructure	Data stays on hardware the library controls directly
Uptime dependency	Depends on internet connection and vendor's service	Depends on local hardware and network reliability

Which suits which library

Cloud-based systems tend to be the better fit for smaller libraries, schools, and organisations without dedicated IT staff, since there's no server to maintain and no in-house expertise required to keep it running. They also suit multi-branch or multi-site organisations well, since every location accesses the same system over the internet without needing local servers of their own.

On-premise systems still appeal to organisations with strict data residency requirements, existing in-house IT capacity, or a preference for keeping infrastructure entirely under their own control — some government, legal, or high-security archive environments fall into this category. It's worth weighing this alongside data protection obligations; see our guide on GDPR and data protection considerations for library software (coming soon) if patron or member data privacy is a major factor in your decision.

Is there a middle ground?

Some organisations land between the two extremes: an on-premise system hosted in a private data centre rather than a cupboard on-site, or a cloud system where the vendor offers a dedicated (rather than shared) instance for institutions with stricter compliance needs. These arrangements exist mainly for large organisations with specific regulatory or security requirements — for most libraries, the practical choice is genuinely binary: hand hosting to a vendor, or keep it in-house.

Questions worth asking a vendor either way

• For cloud systems: where is data physically hosted, and does that location matter for any data protection rules you're subject to?
• For on-premise systems: what are the minimum server specifications, and who is responsible for patching the underlying operating system?
• For both: what happens to your data if you leave — can you export it in a standard, reusable format?

How this affects overall cost

Deployment model is one of the biggest single drivers of total cost of ownership, alongside collection size and which modules you need. For a full breakdown of how library software is typically priced either way, see how much does library management software cost?