Softwr

Documentation · head to head

Scalar vs Stainless

Scalar logo

Scalar

Documentation

Open source API reference renderer and request client generated entirely from an OpenAPI document

From
Free
Rated
-
Full reviewWebsite
Stainless logo

Stainless

APIs

Generates client SDKs, API docs, and MCP servers from an OpenAPI spec

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Scalar it documents only what an OpenAPI document can express, so guides, authentication walkthroughs and conceptual pages need a second tool and a second navigation.; Stainless starter and Pro plan prices are not published and require contacting the company.
  • They diverge on capability: Scalar covers OpenAPI driven reference, Stainless covers SDK generation.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Scalar and Stainless actually diverge.

Attributes where Scalar and Stainless differ
AttributeScalarStainless
Pricing modelOpen source, no licence feefreemium
PlatformsWeb, macOS, Windows, Linuxweb, api
CategoryDocumentationAPIs

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 Scalar

  • OpenAPI driven reference
  • Embedded API client
  • Generated code samples
  • Framework adapters
  • Themeable renderer
  • Self hostable
  • Spec validation

Only in Stainless

  • SDK generation
  • MCP server generation
  • Docs site generation
  • Webhooks and streaming support
  • Automated unit tests
  • Git integration

What people use each for

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

Scalar

  • Replacing default Swagger UI on a public API without moving to a hosted documentation vendornot Stainless
  • A framework that already emits an OpenAPI document and needs a reference page mounted on a routenot Stainless
  • An internal API portal that must run inside a private network with no external callsnot Stainless
  • A team that wants readers to make authenticated test calls without leaving the reference pagenot Stainless

Stainless

  • Generating typed SDKs for a public APInot Scalar
  • Producing an MCP server from an existing OpenAPI specnot Scalar
  • Building an API documentation site alongside client librariesnot Scalar
  • Giving open-source APIs a free SDK generation pathnot Scalar

Where each one falls short

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

Scalar

  • It documents only what an OpenAPI document can express, so guides, authentication walkthroughs and conceptual pages need a second tool and a second navigation.
  • The output is only as good as the spec, so an API with thin descriptions and missing examples produces a thin reference and the tool cannot compensate.
  • Deep visual customisation goes beyond the theme variables quickly, and matching an existing brand often means overriding styles against internal class names that can change.
  • Running the embedded client against a production API invites readers to send real requests, which means rate limits, test accounts and CORS configuration become your problem.
  • The open source renderer and the hosted platform advance at different rates, so a feature seen in a demo is not necessarily in the package you self host.

Stainless

  • Starter and Pro plan prices are not published and require contacting the company.
  • The free plan caps APIs at 25 endpoints, which excludes larger production APIs.
  • Overage charges apply per SDK/endpoint/month once limits are exceeded, which can make costs unpredictable at scale.

Pricing, plan by plan

Scalar

Free
  • Open source rendererFree
    • MIT licence, no fee for the renderer
    • Embedded request client
    • Framework adapters

Stainless

Free
  • FreeFree
    • Up to 5 generators (SDKs, docs, or MCP servers)
    • 5 seats
    • APIs with 25 or fewer endpoints
  • Starter$undefined/mo
    • Unlimited generators
    • Expanded seats
    • Private SDKs of any size
  • Pro$undefined/mo
    • Custom enterprise features and pricing
  • Enterprise$undefined/mo
    • Dedicated support
    • SOC 2 compliance reports
    • Purchase order/invoicing with negotiable terms

Which should you pick?

Choose Scalar if

  • You need openapi driven reference.
  • You want to start without paying.
  • You work on Web, macOS, Windows, Linux.
  • You also want embedded api client.
Scalar review

Choose Stainless if

  • You need sdk generation.
  • You want to start without paying.
  • You work on web, api.
  • You also want mcp server generation.
Stainless review

Questions people ask

Is Scalar or Stainless better?
Neither clearly leads. Scalar starts at Free and Stainless at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Scalar or Stainless?
Scalar starts at Free and Stainless at Free.
Does Scalar or Stainless run on more platforms?
Scalar runs on Web, macOS, Windows, Linux. Stainless runs on web, api.
Can I use Scalar for free?
Both have a free tier, so you can try either at no cost before committing.
What is Scalar best used for?
Scalar is most often used for replacing default swagger ui on a public api without moving to a hosted documentation vendor, a framework that already emits an openapi document and needs a reference page mounted on a route, an internal api portal that must run inside a private network with no external calls, a team that wants readers to make authenticated test calls without leaving the reference page. Of those, replacing default swagger ui on a public api without moving to a hosted documentation vendor and a framework that already emits an openapi document and needs a reference page mounted on a route are not what Stainless is typically brought in for.
What can Scalar do that Stainless cannot?
Scalar covers OpenAPI driven reference, Embedded API client, Generated code samples, Framework adapters. Stainless covers SDK generation, MCP server generation, Docs site generation, Webhooks and streaming support.

Answered from the vendors’ own pages

Scalar: Can I use it without paying anything?

Yes. The renderer is open source and self hostable. The hosted platform is a separate paid product.

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

Yes. The Free plan supports up to 5 generators, 5 seats, APIs with 25 or fewer endpoints, and 100 preview builds per month, with email support.

Source
Scalar: Does it replace a full documentation site?

No. It covers API reference. Guides and concepts need a general documentation generator alongside it.

Stainless: Who owns the generated SDK code?

The generated SDK code is owned by the customer and published by Stainless under the Apache 2.0 license.

Source
Scalar: Will my reference go out of date?

Only if your OpenAPI document does. The reference is generated, so there is no second copy to forget.

Stainless: What happens if I exceed my plan's endpoint limit?

Customers exceeding their endpoint limits are billed per SDK, per endpoint, per month for the overage.

Source
Scalar: Does the embedded client send real requests?

Yes, from the reader browser. Plan for CORS, rate limits and a sandbox environment before publishing.

Scalar: What if my API has no OpenAPI document?

Then this is the wrong tool. Producing an accurate spec is the prerequisite, not an optional step.

Share

Related pages

More on Scalar

More on Stainless

Keep looking

Other head to heads