Sentry vs GlitchTip vs Highlight: open-source error monitoring for a Next.js SaaS (2026)

Quick answer (2026): If you want an open-source, self-hosted Sentry alternative for a Next.js SaaS, GlitchTip is the pragmatic default: it is MIT-licensed, it speaks the Sentry SDK protocol so you change only your DSN, and it runs on a small box. Reach for Highlight.io when you want session replay and logs in the same tool as your errors, and keep self-hosted Sentry when you genuinely need its full APM depth and can feed a large server. One thing most listicles skip: Sentry's own code moved to the Functional Source License (FSL), which is source-available, not OSI open source. GlitchTip (MIT) and Highlight (Apache-2.0) are the more permissive picks.

We build the ShipGarden gallery so we can own the stack that funds the life, and error monitoring is one of the first bricks we lay. When a paying customer hits a 500 at 2 a.m., you want to know before they email you. Sentry is the name everyone reaches for, but "Sentry alternative" is now one of the most-searched infra questions for a reason: pricing, self-hosting weight, and the license all give small teams pause. So we tested the three open-source options a Next.js team actually ends up choosing between.

What each one is, in one line

Sentry is the incumbent developer-first error tracking and performance platform: errors, tracing, session replay, profiling, and uptime in one product. Its GitHub repo carries 44,388 stars as of July 2026 (getsentry/sentry).

GlitchTip is a lightweight, Django-based error tracker that reimplements Sentry's ingestion protocol, so your existing Sentry SDKs work unchanged. It is MIT-licensed and adds simple uptime monitoring (GlitchTip backend, GitLab).

Highlight.io is a full-stack open-source monitoring platform: error monitoring plus session replay, logging, and distributed tracing in a single self-hostable tool, licensed Apache-2.0 with 9,345 stars as of July 2026 (highlight/highlight).

The license fork nobody puts on the comparison table

This is the part that actually matters for a company you intend to own for years, and it splits the three cleanly.

Sentry's application code is under the Functional Source License, version 1.1, Apache 2.0 future license (FSL-1.1-Apache-2.0). It is source-available: you can read it, self-host it, and modify it, but the FSL restricts competing commercial use, and it only converts to Apache 2.0 two years after each release. Sentry is honest about this. Its own page is literally titled "We're Fairly Open" (open.sentry.io). The SDKs are permissively licensed; the server is not OSI open source.

GlitchTip's backend is plain MIT (LICENSE, GitLab). Highlight is Apache-2.0 for the core, with an enterprise/ directory carved out under a separate license (highlight/highlight LICENSE). If "I want a real open-source license, no asterisks" is a hard requirement, GlitchTip wins that axis outright, and Highlight is a close second.

Where each one runs, and what that costs you

ShipGarden's whole thing is time-to-first-deploy and the monthly bill, so here is the honest operational picture.

GlitchTip is the featherweight. It is a Django app plus Postgres and Redis, deployable with Docker Compose, and it runs comfortably on a small 1 GB to 2 GB VPS. For a bootstrapped SaaS doing modest event volume, that is a few dollars a month of infrastructure, or you can use GlitchTip's hosted free tier while you are tiny.

Sentry self-hosted is the heavyweight, and its maintainers say so. The official repo describes itself as "feature-complete and packaged up for low-volume deployments and proofs-of-concept" (getsentry/self-hosted, v26.7.1, July 2026). The compose stack pulls in Kafka, ClickHouse, Postgres, Redis, Relay, Snuba, and more; it wants a meaningfully larger box than GlitchTip's Django stack. You can run it, but you are now operating a small data platform, not a single service.

Highlight.io sits in between on effort but does more: because it captures session replay, logs, and traces, it leans on ClickHouse for storage, so its footprint is closer to Sentry's than to GlitchTip's. You are trading a heavier box for a lot more visibility in one place.

Side-by-side

Honest where-each-loses

No tool in the gallery gets a free pass. Here is where we would each hesitate.

Sentry loses on license and weight. The FSL is the deal-breaker if you need OSI open source, and the self-hosted stack is genuinely a lot to babysit for a small team. Its maintainers steering you toward the hosted product for anything past "low volume" is a signal, not an accident. If you love Sentry's depth, the honest move is often to pay for Sentry Cloud rather than self-host it.

GlitchTip loses on depth. It nails error tracking and uptime, and the DSN-only migration is a genuine gift, but it does not give you session replay, deep distributed tracing, or a full APM view. If a bug only reproduces when you can watch the user's session, GlitchTip will not show it to you. Its community is also smaller: the backend repo sits around 355 stars, versus tens of thousands for the other two.

Highlight loses on momentum. It is the most capable open-source option on paper, but maintenance has visibly slowed: the main repo's last push was April 16, 2026, and the last tagged Docker release was August 2025, after the Highlight team joined LaunchDarkly in 2024. The code is Apache-2.0 and still runs, but "who is shipping fixes next quarter" is a fair question to ask before you bet your on-call on it.

What about SigNoz and Bugsink?

Two names come up constantly in the same searches, and they are legitimate, so we will be straight about them. SigNoz is an OpenTelemetry-native observability platform: if you want errors correlated with metrics, logs, and traces and you are already committed to OTel, it is arguably a better fit than any of the three above, though it is an observability tool first and an error tracker second. Bugsink is the minimalist pick, Sentry-SDK-compatible and deliberately stripped down to fast, low-maintenance error capture. If your only requirement is "tell me when something throws, cheaply," Bugsink is worth a look next to GlitchTip.

How to choose

• Bootstrapped Next.js SaaS, small box, want real open source: GlitchTip. Keep your Sentry SDKs, point the DSN at your instance, done. It also sits neatly next to your other self-hosted pieces; if a queued job blows up, you want that surfaced too, which is why we run it alongside our self-hosted background-job runners.
• You want session replay and logs in one tool and can run ClickHouse: Highlight.io, with the maintenance caveat above priced in.
• You need Sentry's full APM depth: run Sentry, but seriously consider paying for the hosted tier instead of operating the self-hosted platform yourself.

Error monitoring is one line item in the larger question of which open-source building blocks you assemble into a Next.js SaaS; if you are speccing the rest of the stack, our open-source Next.js SaaS starter scorecard is the map we keep updating.

Your move: install the Sentry SDK once, then point its DSN at a GlitchTip container this afternoon and see your first real error before dinner.