More about the 5 Best Frontend Error Monitoring Tools.
Datadog is incumbent Enterprise Observability tool with broad capabilities and a high price tag, while Sentry is an upstart in that space with more targeted capability. Both have a high metered pricing plan. Datadog will be more useful for DevOps teams at large companies, while Sentry is for large engineering organizations looking to guarantee quality. For a lower-cost alternative focused on small teams for 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.