Grafana + Prometheus + Loki is the cloud-native OSS stack. Splunk is the enterprise log analytics + SIEM standard. The gap in cost and capability is huge. Here's how to think about each.
Splunk SPL is a decades-matured query language purpose-built for log search, correlation, and compliance. Nothing in OSS matches its ergonomics for ad-hoc log analysis at scale.
Grafana + Loki uses LogQL — fine for pattern search and label filtering, less powerful than SPL for complex log analytics.
At 10+ TB/day of log ingest, Splunk's architecture is still the reference for interactive query.
Grafana's metrics UX is best-in-class — far more polished than Splunk's for Prometheus-style time-series.
Splunk has metrics too (Splunk Metrics), but it is less loved than its log capabilities.
For a monitoring dashboard experience, Grafana wins.
Splunk Enterprise Security (ES) is the SIEM standard. Hundreds of correlation rules, compliance mappings (PCI, HIPAA, NIST), threat intel integrations.
Grafana has no native SIEM; teams build on top of Loki + alerting or use a separate tool.
If your SOC runs on Splunk ES, Grafana cannot replace it.
Atatus consolidates APM + infra + logs + RUM + SIEM-light in one managed platform at flat per-host pricing.
Replaces the LGTM stack's ops burden; covers mid-market SIEM use cases without Splunk's enterprise license.
OTel-native, PromQL-compatible, and accepts Filebeat / Fluent Bit input directly.
Pros
Cons
Pricing: $0 license + ops team
Best for: Teams with platform engineering muscle
Pros
Cons
Pricing: Workload / per-GB ingest
Best for: Enterprises, SOCs, compliance-heavy
Pros
Cons
Pricing: Flat per-host, all signals included
Best for: Mid-market priced out of Splunk, tired of LGTM ops
Grafana + LGTM is the open-source answer when you have the engineering team to run it; Splunk is the enterprise answer when SIEM depth matters and budget is available. Atatus sits in the middle: managed, flat-priced, and covering most of what both do minus Splunk's SIEM depth.
Unified APM, logs, RUM, infrastructure monitoring, and SIEM in one AI observability platform. Flat pricing, zero bill shock.