OpenSearch vs Grafana Loki
Both are free/open-source alternatives to Splunk. Here's how they stack up — verified facts, no spin.
OpenSearch
TOP PICKThe Apache-2.0 search and log-analytics platform (the Elasticsearch fork).
OpenSearch is a community-driven fork of Elasticsearch and Kibana, kept under the Apache-2.0 license. It ingests, indexes, and searches logs and events at scale, with dashboards and a security-analytics plugin for SIEM use — the closest open feature parity to Splunk's core.
Grafana Loki
Cost-efficient log aggregation that indexes labels, not full text.
Loki, from Grafana Labs, keeps log storage cheap by indexing only metadata labels instead of full text, and pairs with Grafana for querying and dashboards. It is a lightweight, low-cost way to centralize logs when you don't need Splunk's full SIEM surface.
Side by side
| OpenSearch | Grafana Loki | |
|---|---|---|
| Sovereignty Score | 88 | 86 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first | Yes | Yes |
| License | Apache-2.0 | AGPL-3.0 |
| Pricing | Free / self-host; managed options available from AWS and others | Free / self-host; optional Grafana Cloud |
OpenSearch is Macrostack's recommended Splunk alternative, so it's our pick here.
OpenSearch
Strengths
- +Truly open (Apache-2.0), no source-available or field-of-use restrictions
- +Closest feature parity to Splunk — search, dashboards, and a SIEM plugin
- +Large ecosystem inherited from the Elasticsearch/Kibana lineage
Trade-offs
- −Cluster operations (sharding, JVM tuning) have a real learning curve
- −Resource-hungry at large data volumes
- −Different query language — not a drop-in for Splunk's SPL
Grafana Loki
Strengths
- +Very cost-efficient storage via label-based indexing
- +Integrates natively with Grafana dashboards you may already run
- +Simpler to operate than a full search cluster
Trade-offs
- −Label-only indexing makes ad-hoc full-text search slower than OpenSearch or Splunk
- −No built-in security-analytics/SIEM layer
- −AGPL-3.0 network copyleft matters if you offer it as a service
More Splunk head-to-heads
Facts verified 2026-07-09. Licenses and pricing change — spotted something out of date? That's a correction we want.