Start with the right question
A browser breakdown describes the software labels in a measured dataset. It becomes useful when it helps you decide where to inspect navigation, investigate an error, or test an important task.
Keep browser family, device category, viewport, and input method distinct. A narrow window is not the same thing as a phone, and a category label is not proof of a compatibility problem.
Read the denominator, not just the percentage
Decide whether your report counts sessions, events, or recognized users. Show the time window and any exclusions. A percentage without its population can look precise while answering the wrong question.
Preserve an unknown category when classification is uncertain. For implementation details, MDN’s browser-detection guide explains why a user-agent label should not replace feature detection.
Separate device from viewport
Use device reports for context and responsive tests for the space a page actually has.
Compare the two lensesMake the next test reproducible
Record the browser, operating system, viewport, and steps for the actual visitor task.
Build a testing checklist