Open-source AppSignal alternatives

Sentry is a debugging platform that helps developers detect, trace and fix problems in their applications. It collects crash reports and errors from running software, groups them into issues, and adds the context needed to understand what happened, alongside performance monitoring for slow requests and transactions.

Integration happens through official SDKs covering web, mobile, desktop, server and game platforms, from JavaScript, Python and PHP to Go, Rust, Java, Kotlin, Swift, Flutter, Unity, Unreal Engine and Godot. The server itself is a Python application built on Django, and topics also mention CSP report collection and application performance monitoring.

Sentry is source available, and its license is listed as 'Other' on GitHub rather than a standard open-source license. It can be run on your own infrastructure, and the company also operates the hosted service at sentry.io. It is used by engineering teams of all sizes as a first stop when something breaks in production.

SigNoz is an observability platform, open source and built on OpenTelemetry. It aims to replace a fragmented monitoring stack with a single place for logs, metrics, traces, alerts, exceptions and dashboards, and it presents itself as useful for both engineering teams and their AI agents.

The APM view follows how each service performs, covering latency, error rate, throughput, Apdex, the busiest endpoints, and calls to databases and external services. Log management supports ingesting, searching and correlating logs with traces and metrics through a visual query builder. Dashboards can be built with a query builder, PromQL or ClickHouse SQL, infrastructure monitoring covers Kubernetes clusters, pods, nodes and host resources, and LLM and AI observability traces prompts, tool calls, tokens, latency and cost.

You can choose how to run it. SigNoz Cloud is fully managed, with a 30-day free trial and usage-based pricing that starts at $49. Enterprise options cover cloud, bring-your-own-cloud and self-hosted deployments with extra support and controls. The free Community edition runs in your own infrastructure via Docker, Kubernetes or Linux. The repository license is listed as 'Other' on GitHub.

HyperDX is an open-source observability platform for working out why production is broken. It brings logs, metrics, traces, errors and session replays into one place, and works as a search and visualization layer on top of ClickHouse and OpenTelemetry, which the authors compare to Kibana for ClickHouse. It is a core component of ClickStack.

It is schema agnostic and can sit on top of an existing ClickHouse schema. Searching uses full-text and property syntax such as level:err, with SQL as an option, events can be compared with event deltas, high-cardinality events can be charted on dashboards, and alerts can be set up in a few clicks. Live tail shows the newest logs and traces, JSON strings can be queried natively, OpenTelemetry works out of the box, and APM views cover HTTP requests down to database queries.

One deployment option is ClickStack, a bundle of ClickHouse, HyperDX, an OpenTelemetry Collector and MongoDB, and HyperDX can instead be pointed at your own ClickHouse instance. It can also be used with ClickHouse Cloud. The project is MIT licensed and written in TypeScript.

This repository packages Sentry for self-hosting. It lets organizations run the whole Sentry platform on their own server without paying for the hosted product, and the project describes it as feature-complete but aimed at low-volume deployments and proofs of concept. The entry is listed under the name Develop, taken from the documentation site.

Sentry maintains a minimal setup that works out of the box for simple cases, built on Docker and Docker Compose with a bash-based install and upgrade script. It comes with no guarantees or dedicated support, so users are expected to rely on the community on Discord. For larger installations the repository acts as a blueprint of how Sentry services connect, and the docs cover configuration, upgrades, backup and restore, and production enhancements.

The code is distributed under Sentry's fair-source license rather than a standard open-source one. Documentation also explains the small number of differences between self-hosted and the SaaS version, along with relocation tooling for moving to Sentry's hosted service.

Highlight, at highlight.io, is an open-source monitoring platform for developers. Its aim is to give teams one cohesive tool covering the front end and back end, instead of separate products for errors, logs and user sessions.

The core features are session replay, error monitoring and logging, with tracing and metrics also in scope. Console logs from the front end can be analyzed, and errors are embedded alongside the session in which they happened, so you can see what the user was doing beforehand. Session comments let teams discuss user frustration or bugs, there are integrations with other tools, and client SDKs install with a few lines of code.

You can sign up for the free-to-start hosted version at app.highlight.io, or deploy a hobby instance on Linux with Docker, sized at roughly 8 GB of memory, four CPUs and 64 GB of storage. The code is written in TypeScript and Go, and the repository lists the license as Other, so check the licence file for terms.

OneUptime is an open-source monitoring and observability platform that aims to replace a shelf of separate SaaS tools. It covers uptime monitoring, status pages, on-call and alerting, incident management, logs, traces, metrics, APM and error tracking in one application, and adds AI-assisted features such as helping find the root cause and proposing a fix.

Its README maps each module to the tools it can replace: Pingdom and UptimeRobot for uptime checks across websites, APIs, ports, SSL and DNS, StatusPage.io for branded public and private status pages, PagerDuty and Opsgenie for schedules, escalation policies and SMS, call, push or Slack alerts, Incident.io for declaring and triaging incidents with post-mortems, Datadog and New Relic for traces and dashboards, Loggly for logs, and Sentry for exceptions.

The Community Edition is open source under Apache 2.0 and free to self-host, and OneUptime Cloud offers a free-forever plan with no credit card. It is written in TypeScript. It suits small and mid-sized engineering teams that want one platform for reliability work rather than integrating many vendors.

Exceptionless provides real-time error reporting for JavaScript, Node, .NET Core, ASP.NET, Web API, WebForms, WPF, console, and MVC applications. It gathers exceptions and logs, groups them into simple actionable data, and helps teams fix problems quickly. The name means without exception. It is released under the Apache-2.0 license.

The topics mention error monitoring, crash reporting, logging, bug tracking, Elasticsearch, Redis, and the Foundatio library, which indicate the stack behind the server. The application is written in C# with a JavaScript front end.

You can use the hosted service run by the project, which the maintainers describe as reasonably priced and as a way to support the project, along with setup and support services, or run the server yourself. A single Docker command starts a local instance on port 7110. It suits development teams who want an open-source alternative to commercial error-tracking tools.

Uptrace is an open-source application performance monitoring platform. It collects distributed traces, metrics and logs through OpenTelemetry and presents them in a single interface, so teams can monitor applications and troubleshoot problems without switching between separate tracing, metrics and logging tools.

The interface includes a query builder, a service graph, faceted filters, chart annotations and many prebuilt dashboards that appear automatically as metrics arrive. Alerting rules send notifications through email, Slack, WebHook or AlertManager. Data can be ingested via OpenTelemetry, Prometheus, Vector, FluentBit and CloudWatch, Grafana can use Uptrace as a Tempo or Prometheus data source, and single sign-on works through OpenID Connect.

Uptrace is written in Go with a Vue front end, stores telemetry in ClickHouse and keeps metadata such as alerts in PostgreSQL. It is licensed under AGPL-3.0 and can be self-hosted with Docker, and a cloud demo needs no login. The project says it is meant to cut monitoring costs, which suits engineering teams comparing self-hosted APM options with commercial observability suites.

Traceway is an observability platform built natively on OpenTelemetry. It brings logs, traces, metrics, exception tracking, session replay, AI tracing and on-call paging into one product, and you can start by pointing an OTLP exporter at it without a separate collector or a vendor-specific SDK for each language.

Logs are structured and linked to traces, so you can jump from a log line to its span. Traces show end-to-end waterfalls, endpoint views rank routes by latency percentiles and error rate, and exceptions are grouped into ranked issues with source map support. There is experimental profiling with flame graphs, session replay for web and Flutter apps, and LLM observability covering cost, tokens and latency.

The project is written in Go, licensed under MIT and says that every feature ships in the open-source build with no open-core split. You can self-host it for free, using a setup the README says takes about 90 seconds, or run it on Traceway Cloud if you prefer not to manage infrastructure. It suits engineering teams looking for one tool to find and diagnose production problems.