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Cosmic vs KeystoneJS: Which is Better in 2026?

Choosing between Cosmic and KeystoneJS comes down to understanding what each tool does best. This comparison breaks down the key differences so you can make an informed decision based on your specific needs, not marketing claims.

Bottom line: KeystoneJS wins this matchup. Sanity is our overall Headless CMS pick. Sanity is our free Headless CMS pick. Pick Cosmic if you need headless CMS.

··Methodology
Editor reviewed0 verified reviews comparedPricing checked Oct 2026

Short on time? Here's the quick answer

We've tested both tools. Here's who should pick what:

Cosmic

Headless CMS with AI to build and deploy applications 10x faster.

Best for you if:

  • • You want significantly speeds up development and content creation with AI
  • • You want offers a balanced experience for both developers and content editors

KeystoneJS

Headless CMS and GraphQL API framework

Best for you if:

  • • You want a fully free tool (Cosmic requires payment)
  • • You want good headless CMS
  • • You want graphQL API
At a Glance
CosmicCosmic
KeystoneJSKeystoneJS
Starts at
FreeFree tier available
FreeFree tier available
Best For
Headless CMSDeveloper Tools
Rating
4.3/5G2 4.34.6/5G2 4.6
Free plan
 Yes Yes
Watch out for
Overage fees not explicitly detailedn/a

Choose Cosmic or KeystoneJS?

Cosmic

Choose Cosmic if

Headless CMS with AI to build and deploy applications 10x faster.

  • You want significantly speeds up development and content creation with AI
  • You want offers a balanced experience for both developers and content editors
  • Your work is headless CMS-shaped, not developer tools-shaped
KeystoneJS

Choose KeystoneJS if

Headless CMS and GraphQL API framework

  • You want a fully free tool (Cosmic requires payment)
  • You want good headless CMS
  • You want graphQL API
  • Your work is developer tools-shaped, not headless CMS-shaped
Cosmic logo

Cosmic

Headless CMS with AI to build and deploy applications 10x faster.

Visit Website
TOP RATED
KeystoneJS logo

KeystoneJS

Headless CMS and GraphQL API framework

Visit Website
FeatureCosmicKeystoneJS
Pricing ModelFreemiumFree
User Rating
★4.3/5
6 reviews
★4.6/5
11 reviews
Categories
Headless CMSAI Agents
Developer ToolsHeadless CMS

In-Depth Analysis

CosmicCosmic

Headless CMS with AI to build and deploy applications 10x faster.

Starts at Free
Good value

Cosmic's pricing is on the higher side compared to some headless CMS providers, especially for the Starter tier at $299/month.

Watch out

Overage fees not explicitly detailed

Strengths

  • +Significantly speeds up development and content creation with AI.
  • +Offers a balanced experience for both developers and content editors.
  • +Provides enterprise-grade security and collaboration features.
  • +Highly flexible and integrates well with various frameworks and tools.
  • +99.9% Uptime SLA and global CDN for reliable performance.

Weaknesses

  • -Reliance on AI might require trust in generated content/code.

Key features

AI Agents (Content, Code, Computer Use)AI Workflows (Multi-step, Scheduled, Parallel Steps)Intuitive Content EditingAI-powered Content Generation (summaries, SEO, translations)Easy Media ManagementDeveloper Tools (API, open-source SDKs, webhooks)

KeystoneJSKeystoneJS

Headless CMS and GraphQL API framework

Starts at Free
Great value

KeystoneJS offers an incredibly generous pricing model, being entirely free and open source.

Strengths

  • +Good headless CMS
  • +GraphQL API
  • +Admin UI included
  • +Open source
  • +Good for developers

Weaknesses

  • -Learning curve
  • -Node.js required
  • -Less content features
  • -Self-hosting needed
  • -Smaller community

Key features

Headless CMSGraphQL APITypeScriptCustom fieldsAccess controlOpen source

Pricing: Cosmic vs KeystoneJS

PlanCosmicKeystoneJS
Tier 1
$0/month
Free
Free
Free
Tier 2
$299/month
Starter
N/A
Tier 3
$499/month
Pro
N/A
Tier 4
Custom/month
Enterprise
N/A

Pricing verified from each vendor's public pricing page. Compare in detail on Cosmic pricing and KeystoneJS pricing.

Who Should Use What?

On a budget?

KeystoneJS is free. Cosmic is freemium.

Go with: KeystoneJS

Want the highest-rated option?

Cosmic: 4.3/5 (6 reviews). KeystoneJS: 4.6/5 (11 reviews).

Go with: KeystoneJS

Value user reviews?

Cosmic: 6 reviews (4.3/5). KeystoneJS: 11 reviews (4.6/5).

Go with: KeystoneJS

3 Questions to Help You Decide

1

What's your budget?

Cosmic is freemium. KeystoneJS is free. Go with KeystoneJS if free matters most.

2

What's your use case?

Cosmic is a headless CMS tool. KeystoneJS is in developer tools. Pick the category that matches your needs.

3

How important are ratings?

KeystoneJS is rated higher: 4.6/5 vs 4.3/5.

Key Takeaways

KeystoneJS

  • Higher user rating: 4.6/5 vs 4.3/5
  • Larger review base (11 reviews)
  • Completely free
  • Our pick for this comparison

Cosmic

  • Better fit for headless CMS

The Bottom Line

KeystoneJS wins this matchup. Sanity is our overall Headless CMS pick. Sanity is our free Headless CMS pick.

Frequently Asked Questions

Is Cosmic or KeystoneJS better?

KeystoneJS is rated in our evaluation. Cosmic is freemium and KeystoneJS is free.

What are Cosmic and KeystoneJS used for?

Cosmic: Headless CMS with AI to build and deploy applications 10x faster.. KeystoneJS: Headless CMS and GraphQL API framework.

What does Cosmic cost vs KeystoneJS?

Cosmic is freemium (free tier + paid plans). KeystoneJS is completely free. Visit their websites for detailed pricing.

Related Comparisons & Resources

Cosmic AlternativesKeystoneJS AlternativesCosmic Full ReviewKeystoneJS Full Review
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