Sandbox refresh intervals and effects
Key Takeaway
Developer and Developer Pro sandboxes can be refreshed after 1 day, Partial Copy sandboxes after 5 days, and Full sandboxes after 29 days. Pick the type by weighing storage, what must be copied, and how often you need a fresh copy.
Refreshing a sandbox replaces it with a new copy of its source org, usually production, so it picks up changes made there since the sandbox was created or last refreshed. A refresh also has side effects, such as a new org ID and the permanent loss of the existing sandbox after you activate the new copy.
Why a sandbox needs a refresh
A sandbox is an isolated copy of your org. After the copy, the sandbox and your org act as independent orgs. Changes to customizations and data in production don't flow into the sandbox, and records created in the sandbox don't flow back. A refresh is how you bring a sandbox back in line with its source org.