Browser Version

Browser version is the number identifying the exact build of a user's browser — Chrome 120 versus Chrome 96, say — one level finer than the browser name itself.

The browser name is enough for a broad decision, but the real engineering decision is made on the version, because support for a new CSS or JavaScript feature depends on the build, not the brand. The value of this data is in finding the tail of the distribution: if three percent of users are stuck on a build several years old, that same group may see a broken page while being lost in the headline numbers. A common trap is trusting the version string in the User Agent, which modern browsers deliberately blur or freeze to make fingerprinting harder, so the exact build is not always available. Browser version should therefore be read for support decisions and test priority, not as a unique identifier of a user.