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Databases · head to head

OpenSearch vs Windmill

OpenSearch logo

OpenSearch

Databases

Open-source search and analytics suite forked from Elasticsearch

From
Free
Rated
-
Full reviewWebsite
Windmill logo

Windmill

Automation Integration

Open-source developer platform for building scripts, workflows, and internal apps

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: OpenSearch diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one; Windmill free self-hosted tier caps SSO users at 10 and workspaces at 3, requiring Enterprise for larger teams.
  • They diverge on capability: OpenSearch covers Full-text search, Windmill covers Script-to-workflow engine.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which OpenSearch and Windmill actually diverge.

Attributes where OpenSearch and Windmill differ
AttributeOpenSearchWindmill
Pricing modelOpen source, no licence fee; managed services billed separatelyopen-source
PlatformsLinux, Docker, Kubernetes, Self-hostedweb, api, linux, windows, mac
CategoryDatabasesAutomation Integration

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 OpenSearch

  • Full-text search
  • OpenSearch Dashboards
  • Log analytics
  • Vector search

Only in Windmill

  • Script-to-workflow engine
  • Auto-generated UIs
  • Self-hosted deployment
  • Git sync
  • SSO support
  • Audit logs

What people use each for

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

OpenSearch

  • Log and observability storage where an Apache-2.0 licence is a requirementnot Windmill
  • Replacing Elasticsearch after the licence change without changing architecturenot Windmill
  • Search plus analytics on one cluster rather than two systemsnot Windmill

Windmill

  • Turning ad-hoc scripts into scheduled jobs and APIsnot OpenSearch
  • Building internal tools from existing Python/TypeScript codenot OpenSearch
  • Self-hosted automation for engineering teamsnot OpenSearch
  • Orchestrating multi-language workflowsnot OpenSearch

Where each one falls short

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

OpenSearch

  • Diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one
  • Operationally heavy in the way Elasticsearch is: cluster sizing, shard strategy and JVM tuning are ongoing work
  • Smaller ecosystem of third-party tooling than Elasticsearch, which most integrations still target first
  • Overkill for plain application search, where a dedicated search engine is far simpler

Windmill

  • Free self-hosted tier caps SSO users at 10 and workspaces at 3, requiring Enterprise for larger teams.
  • Compute unit and seat-based pricing (developer vs. operator seats, worker compute units) adds pricing complexity beyond a flat monthly fee.
  • Email triggers are capped at 100/day on the free tier, limiting event-driven use cases without upgrading.
  • Smaller ecosystem of pre-built integrations compared to more established automation tools like n8n.

Pricing, plan by plan

OpenSearch

Free
  • OpenSearchFree
    • Full functionality
    • Self-hosted
    • No usage limits

Windmill

Free
  • Free / Open-sourceFree
    • Unlimited executions
    • Self-hosted deployment
    • Max 10 users with SSO
  • Enterprise$120/month
    • Unlimited executions and workspaces
    • Uncapped SSO seats
    • 24/7 priority support (3-hour response)

Which should you pick?

Choose OpenSearch if

  • You need full-text search.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want opensearch dashboards.
OpenSearch review

Choose Windmill if

  • You need script-to-workflow engine.
  • You want to start without paying.
  • You work on web, api, linux, windows, mac.
  • You also want auto-generated uis.
Windmill review

Questions people ask

Is OpenSearch or Windmill better?
Neither clearly leads. OpenSearch starts at Free and Windmill at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, OpenSearch or Windmill?
OpenSearch starts at Free and Windmill at Free.
Does OpenSearch or Windmill run on more platforms?
OpenSearch runs on Linux, Docker, Kubernetes, Self-hosted. Windmill runs on web, api, linux, windows, mac.
Can I use OpenSearch for free?
Both have a free tier, so you can try either at no cost before committing.
What is OpenSearch best used for?
OpenSearch is most often used for log and observability storage where an apache-2.0 licence is a requirement, replacing elasticsearch after the licence change without changing architecture, search plus analytics on one cluster rather than two systems. Of those, log and observability storage where an apache-2.0 licence is a requirement and replacing elasticsearch after the licence change without changing architecture are not what Windmill is typically brought in for.
What can OpenSearch do that Windmill cannot?
OpenSearch covers Full-text search, OpenSearch Dashboards, Log analytics, Vector search. Windmill covers Script-to-workflow engine, Auto-generated UIs, Self-hosted deployment, Git sync.

Answered from the vendors’ own pages

OpenSearch: Is OpenSearch free?

Yes, Apache 2.0 licensed under the Linux Foundation. Amazon OpenSearch Service is a paid managed option.

Windmill: What does Windmill cost?

Windmill's Free and Open-source edition is $0/month for self-hosted use with unlimited executions, while Enterprise starts at $120/month with unlimited workspaces and uncapped SSO seats, priced further by developer/operator seats and compute units.

Source
OpenSearch: Why does OpenSearch exist?

Elastic moved Elasticsearch off the Apache 2.0 licence in 2021. AWS forked the last Apache-licensed version, and the project now sits under the Linux Foundation.

Windmill: Is there a free plan and what are its limits?

The free self-hosted plan supports unlimited executions but caps SSO at 10 users, workspaces at 3, groups/permissions at 4, and email triggers at 100 per day.

Source
OpenSearch: Is OpenSearch compatible with Elasticsearch?

It was at the 7.10 fork point. Both have developed independently since, so compatibility weakens with every release and should be verified for the features you use.

Windmill: How is usage metered on Windmill Enterprise?

Enterprise usage is metered through seats (developer seats at $20/month, operator seats at $10/month) and compute units, e.g. $100/month for 2 standard-worker compute units.

Source
Windmill: What happens to a self-hosted Windmill deployment if the company shuts down?

The pricing page addresses this directly as an FAQ topic, noting that self-hosted applications built on the open-source edition can continue running independently of Windmill the company.

Source
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