macOS uses otherwise idle memory for file cache and performance. High used-memory percentage alone is not evidence that the Mac needs optimization.
In diCleaner, the fill level represents the proportion of memory in use. The pressure label and color represent macOS memory-pressure state. These measurements are related, but they are not interchangeable: memory use can be high while pressure remains normal because macOS can reclaim cached or compressed memory.
Use the displayed pressure level as the primary signal. Treat the percentage as a trend indicator rather than a diagnosis or a fixed threshold shared by every Mac.
Look for symptoms
Sustained elevated memory pressure, growing swap use, repeated beachballs, application termination, and poor responsiveness are more useful signals. A brief color or percentage change during application launch, export, compilation, or another burst of work can be normal.
Identify the source
Close documents and apps you no longer need. Use Activity Monitor to find a process that grows continuously or consumes unusual memory under a known workload.
Use a supported memory action
Save work first. The action can release eligible caches or encourage reclaiming memory, but macOS and active apps may use it again immediately.
When it does not help
If pressure returns, reduce the workload, update or restart the responsible app, check plug-ins, and restart the Mac when appropriate.
Memory optimization does not increase physical RAM or repair a memory leak. Do not run it repeatedly merely to maintain a large “free” number.