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Open-Source Observability · grafana

loki

Loki is a log aggregation system from Grafana Labs that indexes log metadata (labels) rather than full log content, making it cheaper and simpler to operate than traditional log systems. It integrates seamlessly with Prometheus metrics and Grafana dashboards, and is particularly well-suited for Kubernetes environments.

Source: GitHub — github.com/grafana/loki
28.5k
GitHub stars
4k
Forks
Go
Primary language
AGPL-3.0
License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

FieldValue
Repositorygrafana/loki
Ownergrafana
Primary languageGo
LicenseAGPL-3.0 — OSI-approved
Stars28.5k
Forks4k
Open issues1.9k
Latest releasev3.7.3 (2026-06-24)
Last updated2026-07-08
Sourcehttps://github.com/grafana/loki

What loki is

Written in Go, Loki uses a label-based indexing strategy similar to Prometheus, storing compressed unstructured logs and only indexing metadata. It operates as a horizontally-scalable, multi-tenant system designed for cost-effective cloud-native deployments, with push-based log ingestion via Alloy (successor to Promtail).

Quickstart

Get the loki source

Clone the repository and explore it locally.

terminalbash
git clone https://github.com/grafana/loki.gitcd loki# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Kubernetes Pod Logging

Automatic scraping and indexing of Kubernetes Pod labels makes Loki a natural fit for containerized deployments seeking integrated observability.

Cost-Optimized Log Storage at Scale

The label-only indexing approach dramatically reduces storage and compute overhead compared to full-text search systems like Elasticsearch, ideal for high-volume environments.

Prometheus-Native Observability Stack

Seamless correlation of metrics and logs using identical label dimensions simplifies operations for teams already invested in Prometheus.

Implementation considerations

  • Agent deployment required: Alloy (or legacy Promtail) must be configured and deployed to collect logs from each source.
  • Label strategy critical: Proper label design is essential for query performance and cost; cardinality explosion can degrade system performance.
  • Storage backend selection: Loki requires external storage (S3, GCS, local filesystem) separate from the core service.
  • Multi-tenancy configuration: If leveraging multi-tenancy, authentication and runtime-config overrides must be set up in advance.
  • Grafana integration: Requires Grafana v6.0+ and datasource configuration for visualization and log querying.

When to avoid it — and what to weigh

  • Require Full-Text Log Search — Loki does not index log contents; searches operate only on labels and log lines. Full-text queries across massive log corpora are not a design goal.
  • Proprietary Software Licensing Required — AGPL-3.0 license requires source disclosure for any derivative works or network-based modifications. Verify commercial use compatibility with legal review.
  • Simple Pull-Based Metrics Architecture — Loki uses push-based log ingestion (unlike Prometheus pull model), requiring agent deployment and management overhead.
  • Non-Cloud-Native Environments — Design emphasizes microservices, Kubernetes, and distributed deployments; single-node, legacy infrastructure may not benefit from Loki's architecture.

License & commercial use

Distributed under AGPL-3.0-only with Apache-2.0 exceptions noted in LICENSING.md. AGPL requires source disclosure for derivative network-accessible works.

AGPL-3.0 is a copyleft license. Commercial use is possible, but requires careful review: any modification or network deployment may trigger source disclosure obligations. Verify with legal counsel before assuming internal or SaaS use is permitted. Grafana Labs offers GEL (commercial license) options; see LICENSING.md for exceptions.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

SignalAssessment
MaintenanceActive
DocumentationStrong
License clarityNeeds review
Deployment complexityModerate
DEV.co fitStrong
Assessment confidenceHigh
Security considerations

Authentication and multi-tenancy require explicit runtime configuration; review auth_enabled flag and runtime-config setup. Fuzzing program active (OSS-Fuzz badge in README). No security incidents or public exploit details found in provided data. Assess network exposure, credential management for agents, and storage backend permissions before deployment.

Alternatives to consider

Elasticsearch/ELK Stack

Full-text search on all log content; higher cost and complexity but more powerful ad-hoc query capabilities. Better for forensic, compliance-heavy use cases.

Datadog Logs

Managed SaaS with full-text indexing, advanced analytics, and integrations. Higher per-ingestion cost but eliminates operational overhead and infrastructure management.

CloudWatch Logs / Azure Monitor Logs

Native cloud-provider logging with IAM integration. Simpler for cloud-first workloads but lock-in and cost visibility concerns at scale.

Software development agency

Build on loki with DEV.co software developers

Loki is ideal for cloud-native teams managing Kubernetes at scale. Consult our DevOps experts to design a cost-effective logging strategy aligned with your observability goals—and navigate AGPL licensing requirements.

Talk to DEV.co

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loki FAQ

Can I search log content with Loki, or only labels?
Loki indexes labels/metadata only. Searches operate on labels and regex against log lines you've already retrieved; full-text indexing of log contents is not supported.
What storage backends does Loki support?
Unknown from provided data. Refer to official documentation (grafana.com/docs/loki/latest/installation/) for supported backends (e.g., S3, GCS, local filesystem, etc.).
Is AGPL-3.0 compatible with my commercial SaaS product?
Requires legal review. AGPL requires source disclosure for network-accessible derivative works. Grafana Labs offers commercial licenses (GEL); consult LICENSING.md and legal counsel before commercial deployment.
Can I use Loki without Grafana?
Yes, Loki is independent. LogCLI and API allow direct query and ingestion. However, Grafana provides the primary UI and is the recommended visualization layer.

Software developers & web developers for hire

Adopting loki is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source observability software in production.

Ready to streamline your logging infrastructure?

Loki is ideal for cloud-native teams managing Kubernetes at scale. Consult our DevOps experts to design a cost-effective logging strategy aligned with your observability goals—and navigate AGPL licensing requirements.