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Logging · head to head

Grafana Loki vs Langwatch

Grafana Loki logo

Grafana Loki

Logging

Log Aggregation for Grafana Stack

From
Free
Rated
-
Full reviewWebsite
Langwatch logo

Langwatch

Machine Learning

LLM engineering platform for testing and evaluating AI agents in production

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Grafana Loki grafana Cloud Logs Pro plan includes only 30-day retention; retention beyond 30 days requires Enterprise plan with minimum $25,000 annual commitment; Langwatch free plan limited to 50k events per month, restricting larger deployments
  • They diverge on capability: Grafana Loki covers Log aggregation, Langwatch covers Agent simulation testing.

Where they differ

Only the attributes on which Grafana Loki and Langwatch actually diverge.

Attributes where Grafana Loki and Langwatch differ
AttributeGrafana LokiLangwatch
Pricing modelfreemiumTiered subscription with usage-based overage charges
PlatformsSelf-hosted (open source), Managed (Grafana Cloud Logs), Enterprise (self-managed with support)Web, Docker, Kubernetes
CategoryLoggingMachine Learning
Founded2014Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Grafana Loki

  • Log aggregation
  • Label-based indexing
  • LogQL language
  • Cost-effective
  • API
  • Webhooks
  • REST
  • Web support

Only in Langwatch

  • Agent simulation testing
  • LLM evaluation
  • OpenTelemetry tracing
  • Langy AI Engineer
  • Governance controls
  • Multiple deployment options
  • Framework support

What people use each for

The jobs each tool is most often brought in to do.

Grafana Loki

  • Cost-sensitive organisations deploying Kubernetes and Prometheus ecosystemsnot Langwatch
  • Teams needing index-free log aggregation for high-volume environmentsnot Langwatch

Langwatch

  • Continuous testing of AI agents before production deploymentnot Grafana Loki
  • Automated test creation from product requirementsnot Grafana Loki
  • LLM response quality evaluation and scoringnot Grafana Loki
  • Production agent monitoring and cost trackingnot Grafana Loki
  • Governance and access control for AI systemsnot Grafana Loki

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Grafana Loki

  • Grafana Cloud Logs Pro plan includes only 30-day retention; retention beyond 30 days requires Enterprise plan with minimum $25,000 annual commitment
  • Open-source version requires self-hosting all infrastructure including storage and scaling

Langwatch

  • Free plan limited to 50k events per month, restricting larger deployments
  • Pricing in EUR may complicate budgeting for US-based teams
  • Usage-based overage model can create unpredictable costs
  • Self-hosted option requires DevOps expertise

Pricing, plan by plan

Grafana Loki

Free

No published plan breakdown. See the Grafana Loki review.

Langwatch

Free
  • DeveloperFree
    • 50k events per month
    • 14-day data access
    • 2 users
  • Growth$29/month
    • 200k events per month included
    • 5 EUR per 100k additional events
    • 30-day data retention
  • Enterprise$undefined/custom
    • Custom event limits
    • Hybrid, self-hosted or on-premises deployment
    • Custom SSO and RBAC

Which should you pick?

Choose Grafana Loki if

  • You need log aggregation.
  • You want to start without paying.
  • You work on Self-hosted (open source), Managed (Grafana Cloud Logs), Enterprise (self-managed with support).
  • You also want label-based indexing.
Grafana Loki review

Choose Langwatch if

  • You need agent simulation testing.
  • You want to start without paying.
  • You work on Web, Docker, Kubernetes.
  • You also want llm evaluation.
Langwatch review

Questions people ask

Is Grafana Loki or Langwatch better?
Neither clearly leads. Grafana Loki starts at Free and Langwatch at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Grafana Loki or Langwatch?
Grafana Loki starts at Free and Langwatch at Free.
Does Grafana Loki or Langwatch run on more platforms?
Grafana Loki runs on Self-hosted (open source), Managed (Grafana Cloud Logs), Enterprise (self-managed with support). Langwatch runs on Web, Docker, Kubernetes.
Can I use Grafana Loki for free?
Both have a free tier, so you can try either at no cost before committing.
What is Grafana Loki best used for?
Grafana Loki is most often used for cost-sensitive organisations deploying kubernetes and prometheus ecosystems, teams needing index-free log aggregation for high-volume environments. Of those, cost-sensitive organisations deploying kubernetes and prometheus ecosystems and teams needing index-free log aggregation for high-volume environments are not what Langwatch is typically brought in for.
What can Grafana Loki do that Langwatch cannot?
Grafana Loki covers Log aggregation, Label-based indexing, LogQL language, Cost-effective. Langwatch covers Agent simulation testing, LLM evaluation, OpenTelemetry tracing, Langy AI Engineer.

Answered from the vendors’ own pages

Grafana Loki: Is there a free tier for Grafana Cloud?

Yes, Grafana Cloud has a Free Forever plan at no cost with no registration required. The free tier is suitable for personal projects and early-stage startups.

Source
Langwatch: Is there a permanent free tier?

Yes, Langwatch's Developer plan is free forever with 50k events per month, 14-day data access, 2 users, and no credit card required. It is specifically designed for individual developers prototyping AI applications.

Source
Grafana Loki: How long is data retained in Grafana's free plan?

The free tier retains metrics, logs, traces, and profiles for 14 days.

Source
Langwatch: What is Langy and how does it save time?

Langy is an AI-powered tool that automates test creation. It converts product requirements into test scenarios, runs simulations, scores results, and generates pull requests with fixes in a median of 14 minutes.

Source
Grafana Loki: What is the minimum cost for Grafana Enterprise?

Grafana Enterprise has a minimum annual commitment of 25,000 dollars.

Source
Langwatch: What frameworks does Langwatch support?

Langwatch works with LangGraph, LangChain, CrewAI, OpenAI Agents, AWS Bedrock, Azure OpenAI, Vertex AI, and other major LLM frameworks and platforms.

Source
Grafana Loki: Do I need a credit card to use Grafana's free tier?

No, Grafana Cloud's Free Forever plan requires no credit card to get started.

Source
Grafana Loki: How is Grafana Cloud billed?

Grafana Cloud Pro starts at 19 dollars per month with usage-based charges on top. Billing is monthly based on your consumption. Grafana offers automatic volume discounts based on your spending.

Source
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