When and how to upgrade.
SIGNS YOU GENUINELY NEED MORE
Consistent resource limit warnings after caching is correctly configured Checkout slow at peak times Hundreds of orders a day A large catalogue with heavy filtering Admin unusably slow
SIGNS YOU DO NOT
A slow shop with no caching Large unoptimised images Forty plugins One bad speed test
UPGRADING A SHARED PLAN
Client Area > Services > My Services > Upgrade/Downgrade. Usually applies to the same account with no downtime, no migration and no DNS change.
MOVING TO A VPS
A bigger step. You gain dedicated resources and control, and take on server management unless you buy it managed.
For a shop, downtime during a VPS migration is a real cost. Plan the freeze, test thoroughly, and keep the old environment for a week.
BEFORE EITHER
Open a ticket. We will look at your actual resource graphs and tell you honestly whether the problem is the plan or the shop. Frequently it is the shop.