Computed Property
Advanced PronunciationEN/kəmˈpjuːtɪd ˈprɑːpərti/
A computed property is a value the analytics tool derives from existing data through a rule, rather than a value the tracking code sends.
The rule is defined once inside the tool: bucketing a number into ranges, extracting part of a URL, joining two fields, or mapping raw values onto readable labels. Because it is evaluated at query time, the result also applies to historical data, which is the main difference from adding a new property to the code, where the value only exists going forward. The common failure is ignoring input quality: if the source field is empty on a third of events, the computed property is empty there too and those events drop silently out of the chart.
FAQ
If the value can be derived from data you already have and its definition may change, compute it in the tool: the rule can be revised and it applies retroactively. If the value only exists at the moment the event happens, such as the outcome of a server-side check, it must be sent from code because it cannot be reconstructed later.