Sentry vs PostHog

Sentry and PostHog both offer session replay and performance monitoring, but they're built around fundamentally different primary use cases. Sentry's core identity is error tracking: when something breaks in production, Sentry captures the full stack trace, groups related errors intelligently, links issues to the release that introduced them, and surfaces the root cause with enough context to fix it — often including the exact line of code. This laser focus makes Sentry the go-to tool for engineering teams who treat error resolution as a discipline. PostHog's core identity is product analytics: understanding how users move through your product, which features drive retention, and what experiments move your metrics. Both platforms have expanded into each other's territory — Sentry added session replay and Crons monitoring, PostHog added error tracking — but their heritage shapes what each does best.

PostHog's biggest differentiator is its breadth. For the price of a single product, you get event analytics, funnels, retention charts, session recordings, feature flags, A/B testing, surveys, and a data warehouse. For early-stage startups and smaller engineering teams, this consolidation is genuinely valuable — instead of paying for Mixpanel, LaunchDarkly, Hotjar, and a separate error tool, PostHog covers most of those use cases in one platform. It's also open source and self-hostable, which appeals to privacy-conscious teams or those who want full data sovereignty. Sentry focuses on doing fewer things with greater depth: its integration with GitHub, GitLab, and Linear means developers can go from a Sentry error alert to an assigned, tracked issue in seconds.

Pricing models favor different scales. Sentry's free tier gives you 5,000 errors and 10,000 performance transactions per month — enough for indie projects and small apps. PostHog's free tier is extremely generous: 1 million events per month, 5,000 session recordings, and unlimited feature flags at no cost. For growing teams, PostHog tends to stay cheaper longer because it consolidates tooling costs. Sentry's costs scale with event volume and can grow quickly for high-traffic applications with frequent errors — error-heavy apps (like those with 3rd party widget failures or high-churn mobile sessions) can hit billing limits faster than expected.

The session replay capabilities are a common reason teams evaluate both tools simultaneously. Sentry's session replay is tightly integrated with error tracking — you can watch the recording of exactly what a user did before an error occurred, with console logs and network requests correlated to the playback. PostHog's session replay is integrated with behavioral analytics — you can watch recordings of users who dropped off in your checkout funnel, or filter recordings by users who never activated a key feature. Both are genuinely useful, but the replay serves different investigative questions: Sentry helps you understand 'why did the code fail' and PostHog helps you understand 'why did the user fail.' Many mature product teams end up running both for exactly this reason.