Hi, I’m Kayla. I’ve shipped two web apps in the last year—a small fitness app for moms, and a B2B dashboard for a freight team. I ran PostHog and Sentry side by side. I still do.
Short version? Sentry tells me when my code breaks and why. PostHog shows me what users do and what changes help. They overlap a bit, but they feel like different tools in my hands. For an official vendor take on the matchup, skim PostHog’s own write-up of PostHog vs Sentry. If you’d like a deeper, no-fluff teardown of how the two stack up, check out this PostHog vs Sentry field report.
You know what? I thought I could pick one. I couldn’t. I’ll explain.
My real stories, the good and the messy
Story 1: The checkout bug Sentry caught while I was eating tacos
Stack: Next.js front end, Node API, Postgres.
Thing that broke: mobile Safari only. That lovely edge case.
Sentry pinged Slack at 8:32 pm. “TypeError: Cannot read property ‘push’ of undefined.” It showed:
- Browser: Safari 16 on iOS
- Path: /checkout
- Release: 2.4.1
- Breadcrumbs: user tapped “Pay”, then a fetch to /api/cart, then the crash
- Trace: the promise chain, my line number, my name as code owner
I opened the stack trace, saw a null cart item, and fixed it with one guard. I shipped a patch in 12 minutes. Sentry auto-linked the commit, marked the issue as “resolved in 2.4.2,” and the alert went quiet. No more dings. I finished my tacos.
Could I have found this with console logs? Maybe. Hours later, with tears.
Story 2: The funnel drop PostHog showed me in big, clear lines
The B2B dashboard had a 4-step signup. I changed the Step 3 button from “Continue” to “Get Started” (I know, small thing). Next day, PostHog’s funnel showed a cliff. Step 3 to Step 4 fell by 12%.
I watched five session replays. People hovered, then moved their mouse to the top bar and left. The new copy looked like the end of the flow, not the middle. Ouch.
So I used PostHog feature flags. I ran a 50/50 test: “Continue” vs “Get Started.” The old copy won. We kept it. Funnel drop gone. We even saw a small lift later when we changed the color to the same shade as Step 2. PostHog made that change feel safe. If you’re weighing PostHog against more product-led suites like Pendo for this kind of experiment, this frank rundown of Pendo vs PostHog is a solid shortcut.
While that signup tweak was B2B, the same analytics playbook applies to more consumer-focused experiences too. I recently helped a friend prototype a location-based dating MVP, and we pored over this curated roundup of free local sex apps to reverse-engineer how the market leaders onboard new users and keep matches engaged—worth scanning if you want proven growth loops you can borrow for your own product. On the ultra-niche end of the location-based spectrum, examining how city-specific directories compile reviews can spark ideas—take the way Rubmaps’ Delray Beach guide organizes user-submitted ratings and granular location data, a structure that can inspire richer filtering and proximity logic in your own app.
Setup and “do I need a weekend for this?”
- Sentry took me 15 minutes. I pasted the DSN, added the Next.js plugin, turned on source maps, and set up Slack alerts. I also added release tags in CI. That part is worth it.
- PostHog took me about an hour. I added the capture snippet, set my team’s domains, turned on session replay, and built a simple dashboard: signups, weekly active users, key funnel. Later, I added feature flags and cohorts.
Self-hosting? I’ve done both in the past:
- Sentry on-prem felt heavy for me. It ran, but I babysat it.
- PostHog self-host was okay on Kubernetes, but query speed dipped when we got noisy. Cloud was easier for both.
Privacy note: I masked emails and names in both tools. Sentry has PII scrubbing rules. PostHog lets you block events or fields. It’s worth an extra 20 minutes to set that up right.
My day-to-day with each
Here’s how I actually use them, not the glossy tour.
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With Sentry:
- Alerts go to a quiet Slack channel. Only high stuff pings my phone.
- We triage issues every morning. We group dupes, assign owners, and fix top crashes first.
- The performance view shows slow spans. I found one nasty N+1 query. One query turned into 34. One fix, 600ms faster.
- For React Native, Sentry helped with a memory crash on older Android. The release health chart told me it was 3.2.0 only. Rollback saved the day.
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With PostHog:
- My “morning board” shows signups, activation rate, and 7-day retention.
- I check replays when a metric moves. I don’t watch a hundred. I watch five. That’s enough to see a pattern.
- Feature flags are my seat belt for risky UI changes. 10% first, then 25%, then 100% if crash-free and no funnel hit.
- Cohorts help me ask simple, smart questions. Do users who try “Export to CSV” come back more? Yes, by a bit. So we made that button easier to find.
Where each one shines (from my keyboard, not a brochure)
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Use Sentry when:
- An error woke you up last week.
- You need stack traces, not vibes.
- You care about slow pages, cold starts, and release health.
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Use PostHog when:
- You ship product changes often.
- You need funnels, trends, cohorts, and replays in one place.
- You want flags and simple A/B tests without a new stack.
Could you run just one? Maybe. I tried. I kept both.
The rough edges I hit
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Sentry:
- Noise can get loud. Tuning alerts took days. Worth it though.
- Source maps were a pain one time. My CI missed a build step. No readable stack traces until I fixed the upload.
- Performance sampling is a tweak game. Too much data costs more. Too little, you miss the story.
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PostHog:
- Session replay can eat storage if you leave it wide open.
- Event names matter. Messy names, messy charts. I cleaned them a month later and felt silly.
- Self-host queries slowed when our data spiked. Cloud felt faster for us.
Money talk, quick and plain
Both have free plans. Costs rise with volume:
- Sentry bills by errors and traces.
- PostHog bills by events, replays, and tests.
If you’re also looking at PostHog as a possible Google Analytics replacement, this practical head-to-head on PostHog vs Google Analytics spells out the trade-offs clearly.
We started free on both. We paid once the apps got real traffic. No shock bills, but I did set caps. If you also need to tie usage metrics directly to revenue, consider adding Scout Analytics to the mix—it specializes in surfacing the dollars behind the clicks. If you prefer crowd-sourced impressions, the side-by-side ratings on G2 offer a quick pulse on how real teams feel about pricing and support.
Little things that made me smile
- Sentry’s “Suspect Commit” pointed right at my pull request once. Guilty. Fixed it fast.
- PostHog’s “Paths” showed a weird loop: users bounced between Help and Settings. We moved Help into the footer. Loop gone.
So… which one do I pick?
If you’re a small startup with one engineer:
- Pick Sentry if crashes hurt your users today.
- Pick PostHog if your biggest risk is “we built the wrong flow.”
If you can run both, do it. I keep Sentry as my seat belt. I keep PostHog as my map. One keeps me safe. One gets me farther.
And yes, I still watch a few replays with coffee. It’s the closest thing to sitting next to a user without bugging them. Funny how much you learn just by watching where the mouse goes.
If you’ve got a weird stack or a hard problem, tell me. I’ve probably got a story—and a scar—to match.