Billing/Upgrades FAQ

This page answers questions related to upgrading projects and billing.

To learn more about licenses, see Licenses.

Questions about projects are covered in Projects FAQ.


What is the difference between free and paid service?

Learn more about Trial Projects.

With licensed projects and other paid plans, the main differences are:

  • increased resource quotas

  • better quality of hosting

  • prioritized support.

We encourage you to make an account and explore our product for free. Other than lack of internet access for free projects, there is no difference in functionality between the free and for-pay versions of CoCalc. Everything is private by default for free users. You can make as many projects as you want. You can start teaching a course in CoCalc for free, then add a license later so that your students have a much better quality experience (for a small fraction of the cost of their textbook).

How do I get an invoice with specific information?

After purchasing, please email us at, reference what you bought, and tell us the payer’s name, contact information and any other specific instructions. We will then respond with a custom invoice for your purchase that satisfies your unique requirements.

Can I pay via wire transfer?

For purchases above $100 we support wire transfers. Please contact with all relevant details about your intended purchase.

The free servers really are massively overloaded, so it is well worth it to upgrade to member hosting, enable internet access, etc.

In case you’re teaching a course and bought a license to manage that course: please read 2. Install your license(s) in the course file..

Quota upgrades

What is “member hosting”?

There are two types of projects: “trial (free) projects” and “member projects”. Trial projects run on heavily loaded computers sharing the same node with many other projects and system tasks. These nodes might also shutdown at any time, causing your currently running project to interrupt your work and restart.

Member-hosted projects are moved to less loaded machines, which are reserved only for paying customers and aren’t restarted on a daily basis. The cluster scales up dynamically to accommodate for a varying number of member-projects.

Working in member-hosted projects feels much smoother because commands execute more quickly with lower latency, and CPU, memory and I/O heavy operations run more quickly.

What exactly is the “network access” quota?

(This was formerly called the Internet access quota.)

Despite the fact that you are accessing CoCalc through the internet, you are actually working in a highly restricted environment. Processes running inside a free project are not allowed to directly access the internet. (We do not allow such access for free users, since when we did, malicious users launched attacks on other computers from CoCalc.) Enable internet access by adding the “internet access” quota.

What exactly is the “idle timeout” quota?

By default, free projects stop running after about 30 minutes of idle time. This makes doing an overnight research computation – e.g., searching for special prime numbers – impossible.

There is an advanced license option to prevent idle timeouts completely: see Always running. Processes might still stop if they use too much memory, crash due to an exception, or if the server they are running on is rebooted.

Projects do not stop if you are continuously using them, and there are no daily or monthly caps on how much you may use a CoCalc project, even a free one.

See also: Software development/idle timeout.


There is also a user-configurable timeout, the Standby timeout, which does not stop the project.

What are Shared CPUs / vCPUs?

You can specify 1, 2, or 3 Shared CPUs, also known as Google Cloud vCPUs for a site license. To keep prices low, vCPUs may be shared with other projects, though member hosting very significantly reduces competition for CPUs.

To learn more about using of more than one vCPU per project, see Multiple CPUs.