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Machine Learning · head to head

LangChain vs Stellarium

LangChain logo

LangChain

Machine Learning

Build applications with LLMs through composability

From
Free
Rated
-
Full reviewWebsite
Stellarium logo

Stellarium

Education

Free open source desktop planetarium software, distinct from the paid Stellarium Mobile Plus app

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: LangChain the free Developer plan of LangSmith is limited to 1 seat; Stellarium it is desktop-only software, so it has no native touch-optimised phone interface; the similarly named mobile app is a different paid product from a different company.
  • They diverge on capability: LangChain covers Chains and agents, Stellarium covers Photorealistic sky rendering.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which LangChain and Stellarium actually diverge.

Attributes where LangChain and Stellarium differ
AttributeLangChainStellarium
Pricing modelfreemiumOpen source, no licence fee
PlatformsLinux, Mac, WindowsWindows, macOS, Linux
CategoryMachine LearningEducation
Founded2022Unknown

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 LangChain

  • Chains and agents
  • Retrieval-augmented generation
  • Memory management
  • Tool integration
  • Prompt templates
  • OpenAI
  • Anthropic
  • Hugging Face

Only in Stellarium

  • Photorealistic sky rendering
  • Large object catalogue
  • Telescope control
  • Scripting engine
  • Free and open source
  • Plugin ecosystem

What people use each for

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

LangChain

  • Building LLM applications and agents in Python or JavaScriptnot Stellarium
  • Tracing and debugging LLM chains and agent runsnot Stellarium
  • Evaluating prompt and model changes against datasetsnot Stellarium

Stellarium

  • A student or educator wanting a serious, scriptable planetarium tool without a budget line itemnot LangChain
  • An amateur astronomer wanting telescope control from desktop software they can inspect and modifynot LangChain
  • Someone running a planetarium display or public astronomy event on a scripted shownot LangChain
  • A hobbyist who wants a large object catalogue without paying a subscription, and does not need a phone appnot LangChain

Where each one falls short

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

LangChain

  • The free Developer plan of LangSmith is limited to 1 seat
  • Base traces are retained for 14 days only; 400 day retention costs extra
  • Included traces are capped at 5,000 per month on Developer and 10,000 per month on Plus, with everything beyond billed pay as you go
  • Self hosted and hybrid deployment of LangSmith is Enterprise only
  • Custom SSO, RBAC and ABAC are Enterprise only
  • A support SLA is Enterprise only
  • Enterprise pricing is by quote with no published rate

Stellarium

  • It is desktop-only software, so it has no native touch-optimised phone interface; the similarly named mobile app is a different paid product from a different company.
  • As a volunteer-maintained open source project, support is community-based rather than a guaranteed commercial help desk.
  • The interface, while capable, is less immediately intuitive for a first-time user than a polished commercial phone app.
  • Telescope control and some advanced plugins require additional setup that a non-technical user may find fiddly.
  • Because it shares a name with the unrelated paid Stellarium Mobile Plus app, buyers researching pricing online can easily conflate the two products.

Pricing, plan by plan

LangChain

Free
  • Open SourceFree
    • Full framework
    • Community support
  • LangSmith$39/month
    • Debugging
    • Monitoring
    • Testing

Stellarium

Free
  • Stellarium DesktopFree
    • Full software, GPL licensed
    • No account, ads or subscription
    • Community-developed plugins

Which should you pick?

Choose LangChain if

  • You need chains and agents.
  • You want to start without paying.
  • You work on Linux, Mac, Windows.
  • You also want retrieval-augmented generation.
LangChain review

Choose Stellarium if

  • You need photorealistic sky rendering.
  • You want to start without paying.
  • You work on Windows, macOS, Linux.
  • You also want large object catalogue.
Stellarium review

Questions people ask

Is LangChain or Stellarium better?
Neither clearly leads. LangChain starts at Free and Stellarium at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, LangChain or Stellarium?
LangChain starts at Free and Stellarium at Free.
Does LangChain or Stellarium run on more platforms?
LangChain runs on Linux, Mac, Windows. Stellarium runs on Windows, macOS, Linux.
Can I use LangChain for free?
Both have a free tier, so you can try either at no cost before committing.
What is LangChain best used for?
LangChain is most often used for building llm applications and agents in python or javascript, tracing and debugging llm chains and agent runs, evaluating prompt and model changes against datasets. Of those, building llm applications and agents in python or javascript and tracing and debugging llm chains and agent runs are not what Stellarium is typically brought in for.
What can LangChain do that Stellarium cannot?
LangChain covers Chains and agents, Retrieval-augmented generation, Memory management, Tool integration. Stellarium covers Photorealistic sky rendering, Large object catalogue, Telescope control, Scripting engine.

Answered from the vendors’ own pages

LangChain: Does LangChain charge for its services?

LangChain's main website does not display pricing. However, LangSmith (a related platform) offers both free and paid plans. Visit the dedicated pricing page or contact LangChain for details.

Source
Stellarium: Is Stellarium really free?

The desktop software is free and open source under the GPL licence. The separate mobile app, Stellarium Mobile Plus, is a different paid product.

LangChain: How can I learn about LangChain pricing?

Click on the Pricing link in navigation or use the Try LangSmith or Get a demo options to explore pricing for LangChain's commercial offerings.

Source
Stellarium: Is the mobile app made by the same team?

No. Stellarium Mobile Plus is built by Noctua Software, a different company, and is sold on subscription.

Stellarium: What platforms does the free version run on?

Windows, macOS and Linux desktop.

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