Best of · Observability
Best metrics tools (2026)
Stack Gems reviews 6 metrics tools: 5 free or open source, 1 paid or paid-led. These are the top 6, each with its verdict and the Catch we would want to know before installing it.
Order: free and open source first, then hosted products with a real free tier, then paid-led; catalog order inside each group, with quiet or archived repos last. Not a score, and no tool pays for its place.
6 reviewed · 6 shown in full
Free / OSS · AGPL-3.0 · 77.4k GitHub stars
VerdictThe universal observability dashboard.
CatchDashboard sprawl becomes a maintenance burden. Learning PromQL or LogQL takes time. Self-hosting requires infrastructure.
Free / OSS · Apache-2.0 · 66.6k GitHub stars
VerdictThe foundation of cloud-native metrics.
CatchSingle-node storage limits scale. PromQL has a learning curve. High cardinality labels cause problems.
Free / OSS · Apache-2.0 · 17.9k GitHub stars
VerdictApache-2.0 Prom-compatible TSDB. CE free; downsampling/anomaly/multi-tenant Enterprise.
CatchStorage/metrics engine - not Grafana/SigNoz APM UI. Downsampling, anomaly detection (vmanomaly), and advanced multi-tenant stats/rate-limit bits are Enterprise. Distinct from Prometheus encyclopedia and SigNoz all-in-one.
Free / OSS · OSS/MIT · 26.3k GitHub stars
VerdictMIT self-hosted server and container monitoring when Prometheus + Grafana is too much — free, quick to run, but a fixed metric set on a single-hub design.
CatchFixed set of host and container metrics, not a general metrics platform: no PromQL, no custom app metrics, no logs or traces. The hub is one PocketBase (SQLite) app, so think small fleets, not hundreds of nodes with long high-resolution retention. The agent needs host access (and the Docker/Podman socket for container stats), so scope it like any privileged daemon. Vs Uptime Kuma (endpoint uptime), Dozzle (container logs) and Prometheus + Grafana (full metrics stack): Beszel is the resource-history-and-alerts middle seat.
Free / OSS · Apache-2.0 · 13.9k GitHub stars
VerdictThe first thing to install on any Linux box you want to watch with Prometheus.
CatchIt only exposes metrics: you still need a Prometheus server (or a compatible scraper) to store them and something like Grafana to view and alert on them. Running it in a container needs host networking, the host PID namespace and a read-only bind mount of / with --path.rootfs, or it ends up measuring the container instead of the machine. Windows needs the separate windows_exporter, and NVIDIA GPUs need dcgm-exporter.
Paid-led · Paid
VerdictThe everything platform—if you can afford it.
CatchExpensive at scale—costs surprise teams. Vendor lock-in is significant. Feature creep makes the platform complex.
FAQ
- What is the top free pick among metrics tools?
- Grafana leads the Stack Gems list for metrics tools. Verdict: The universal observability dashboard.
- How many metrics tools does Stack Gems review?
- 6: 5 free or open source, 1 paid or paid-led. Each review has a verdict and an honest Catch; no tool pays for its spot.
- Which metrics tools can I self-host for free?
- Grafana, Prometheus, VictoriaMetrics, Beszel and node_exporter.
- Which metrics tools have the most GitHub stars?
- Grafana (77.4k), Prometheus (66.6k), Beszel (26.3k), per GitHub on 2026-10-19. Stars measure attention, not fit; read the Catch.
- What is the catch with Grafana?
- Dashboard sprawl becomes a maintenance burden.
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