OpenSearch vs Grafana Loki
Both are alternatives to Splunk. Here's how they stack up — verified facts, no spin.
Also searched as Grafana Loki vs OpenSearch — same comparison, one verdict.
OpenSearch and Grafana Loki are closely matched on ownership (88 vs 86) — this one comes down to pricing and to which trade-offs below you can live with.
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
10 points of comparison, every one read from a verified field. Green marks the side that wins a row outright. A dash means we do not hold that fact — never that it is zero.
| OpenSearch | Grafana Loki | |
|---|---|---|
| Sovereignty ScoreOur transparent 0–100 composite for data ownership and exit cost. | 88 | 86 |
| Open source | Yes | Yes |
| Self-hostable | Yes | Yes |
| Local-first data | 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 |
| RAM to run it wellThe figure that actually matters, not the vendor's minimum. | 8 GB heap on a 16 GB machine | 4 GB |
| Realistic running costWhat the box costs each month if you run it yourself. | $60–120/mo for a small cluster, against Algolia pricing that bills per search operation | $20–40/mo plus object storage, against Splunk pricing that is famously per-GB-ingested |
| Setup timeHonest first-install estimate, not the marketing quickstart. | Half a day for one node, a week for a production cluster | Half a day |
| Ongoing maintenanceThe part nobody budgets for. | Real. Shard sizing, JVM heap and index lifecycle are all yours. | Moderate. Label hygiene and retention are ongoing. |
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
Which one fits you
The trade-offs above, turned into a decision. Find the line that describes your team.
Choose OpenSearch
if a lower exit cost matters more to you than any single feature, and truly open (Apache-2.0), no source-available or field-of-use restrictions.
Choose Grafana Loki
if very cost-efficient storage via label-based indexing.
Neither, yet
if both carry a real cost you should weigh first — cluster operations (sharding, JVM tuning) have a real learning curve, and label-only indexing makes ad-hoc full-text search slower than OpenSearch or Splunk. If either of those is a dealbreaker for your team, the shortlist is wrong rather than the choice.
What it takes to run these yourself
Real requirements and honest running costs, not the vendor quickstart.
Self-hosting OpenSearch
8 GB heap on a 16 GB machine RAM · Half a day for one node, a week for a production cluster
$60–120/mo for a small cluster, against Algolia pricing that bills per search operation
Self-hosting Grafana Loki
4 GB RAM · Half a day
$20–40/mo plus object storage, against Splunk pricing that is famously per-GB-ingested
OpenSearch vs Grafana Loki — common questions
Is OpenSearch a better fit than Grafana Loki for log management & siem?
It depends on what you are optimising for, and the honest split is this: OpenSearch scores 88 to Grafana Loki's 86 on data ownership and exit cost, so it is the safer choice if you care about being able to leave. Grafana Loki earns its place on a different axis — very cost-efficient storage via label-based indexing. Neither is a wrong answer for every team; the table above is the actual comparison.
What happens if we want to switch later?
OpenSearch keeps its data local or in open formats, so leaving is an export rather than a negotiation. Grafana Loki is still self-hostable, so the files stay on your server either way — but it is not local-first by design, so check what its export produces before you rely on it.
Can I self-host OpenSearch or Grafana Loki?
Both can be self-hosted. The difference is what it costs you in time rather than whether it is possible — see the setup and maintenance rows above.
Are OpenSearch and Grafana Loki both alternatives to Splunk?
Yes — both appear in our Splunk comparison, which is why they are worth putting side by side. People usually arrive here already having decided to move off Splunk and now choosing between the two replacements, which is a narrower and much easier question.
More Splunk head-to-heads
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Facts verified 2026-07-09. Licenses and pricing change — spotted something out of date? That's a correction we want.