More about the 5 Best Frontend Error Monitoring Tools.
Both Sentry and DataDog are full featured error monitoring platforms. Sentry is more focused on engineering, while DataDog has better platform support and management reporting. Both tools are very expensive. For a cheaper, front-end error tracking alternative that has great reporting and noise management, consider TrackJS.
With TrackJS, the focus is on errors occurring on the browser. Filtering is second to none, and the quick views of trending errors are helpful in digging past the 3rd party script noise. It filters down to the core issues.