Read what an extension asks to do
A browser extension declares permissions and site patterns in its manifest. This inspector separates required permissions, optional permissions and content-script matches. Optional permission declarations are requests an extension may make later; they do not show what you have already granted.
Capabilities need context
Access to all sites can be necessary for a content blocker and excessive for a simple calculator. A manifest does not reveal how an extension uses that access. This tool does not read or run extension code, verify its publisher, detect malware or certify safety.
Permission behavior varies by browser and version. Compare unfamiliar names with the Chrome permission reference or Firefox manifest reference.