More about the 5 Best Frontend Error Monitoring Tools.
Sentry is great if your budget supports their business pricing plan. BugSnag may not be as featured, but more competitive at lower event volume. If you are focused on frontend error tracking, 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.