Beneath the Stacktrace section, the Developer tab displays the error's impact on two pie charts: Browser Impact and OS Impact. The purpose of these charts is to gauge the error's impact across different conditions. Sometimes, an error is specific to a browser or operating system.
The Browser Impact section outlines the error's impact by web browser. The pie chart lists the number of error occurrences per browser, as well as each browser's percentage of all occurrences. If an error's impact is significantly higher on a specific browser, it may indicate there's an issue with how your code interacts with the browser.
When analyzing error occurrences by browser, consider that some browsers are more popular than others, and this may impact the number of error incidences. For example, Google Chrome has upwards of 50% of the browser market. If the Browser Impact section indicates a majority of error occurrences are happening on Chrome, it's likely due to Chrome's popularity and not because Chrome is particularly affected by the issue.
The OS Impact section outlines the error's impact by operating system, both by number of occurrences and percentage of total occurrences. If an error's impact is significantly higher on one operating system than the others, it may be that the error is specific to the operating system.
Much like browser usage, some operating systems are more popular than others, and this might impact the distribution of error occurrences. For example, a high percentage of occurrences will likely appear on Android, not because the operating system is especially sensitive to the error, but because it's a highly-used operating system.
Learn more about the other sections on the Developer tab: Stacktrace, HTTP Error Details, Insights, Last Reproduction Steps, and Top URLs.