How to Choose an Error Monitoring Tool

A guide to selecting the right error monitoring and observability platform for your startup. Covers error grouping, alerting, performance monitoring, and how to balance visibility with cost as your event volume grows.

Key Decision Criteria

Error Grouping and Noise Reduction

High Priority

The difference between a good and bad error monitoring tool is whether you see 10 actionable issues or 10,000 raw stack traces. Sentry's fingerprinting algorithm groups related errors intelligently. Datadog and Bugsnag offer similar grouping. Evaluate how each tool handles deduplication — noisy error feeds get ignored by the team.

Pricing Model and Event Volume

High Priority

Sentry offers 5K free errors/month, then Team plan at $26/month for 50K errors. Datadog charges $15/host/month for APM with error tracking included — cheaper if you already use Datadog for infrastructure. Bugsnag offers 7,500 free events/month. At high volume, pricing diverges significantly — model your expected error and event volume before committing.

Performance Monitoring Integration

Medium Priority

Errors rarely happen in isolation — slow queries, memory leaks, and latency spikes cause them. Sentry includes performance monitoring and session replay on paid plans. Datadog offers the deepest APM with distributed tracing across services. Bugsnag focuses primarily on error tracking without built-in APM. Consider whether you want one tool for errors and performance or separate best-of-breed tools.

Framework and Language Support

Medium Priority

Sentry supports 100+ platforms with first-class SDKs for JavaScript, Python, Ruby, Go, and mobile. Datadog covers similar breadth with stronger infrastructure coverage. Bugsnag has solid SDKs for web and mobile. Check SDK quality for your specific stack — some tools have excellent React support but weaker Python or Go SDKs.

Questions to Ask Yourself

Do you need just error tracking or full application performance monitoring?

Error tracking only: Sentry or Bugsnag are purpose-built and cost-effective. Sentry's free tier (5K errors/month) covers most early-stage startups. Full APM (errors + latency + tracing + infrastructure): Datadog provides the most comprehensive observability suite, but expect to spend $15+/host/month. Sentry's performance monitoring is lighter-weight but sufficient for most web applications.

How many production errors does your application generate per month?

Under 5K/month: Sentry's free tier handles this — no cost required. Under 7.5K: Bugsnag's free tier also works. 5K-50K/month: Sentry Team ($26/month) or Bugsnag's paid plans. Budget $25-50/month. Over 50K/month: You either have a serious quality problem to fix or very high traffic. Negotiate volume pricing — Sentry and Datadog both offer custom plans at scale.

Are you already using Datadog for infrastructure monitoring?

If yes, adding Datadog APM and error tracking to your existing setup provides unified dashboards, correlated traces, and single-vendor billing. The incremental cost is often lower than adding a separate error monitoring tool. If no, Sentry is the better starting point — it's laser-focused on application errors with a free tier and faster setup than Datadog's broader platform.

Red Flags to Watch For

Setting up error monitoring but never configuring alert thresholds

Error monitoring is useless if nobody sees the alerts. Configure Sentry or Datadog to alert your team's Slack channel when new issues appear or error rates spike above baseline. Default alert settings are usually too noisy — tune thresholds within the first week to avoid alert fatigue and ignored notifications.

Sending all log output through an expensive monitoring tool

Datadog's log management charges per GB ingested ($0.10/GB indexed). If you're shipping application logs, debug output, and access logs through Datadog, costs escalate fast. Use error monitoring for errors and exceptions specifically. Route verbose logs to cheaper storage (CloudWatch, Loki) and only send high-signal events to your monitoring tool.