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Documentation · head to head

ReadMe vs Sphinx

ReadMe logo

ReadMe

Documentation

Hosted developer hub priced per API project, with docs personalised from live request logs

From
Free
Rated
-
Full reviewWebsite
Sphinx logo

Sphinx

Documentation

Documentation generator built for large technical projects

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: ReadMe pricing is per project, so an organisation with several distinct APIs multiplies the monthly bill rather than adding seats, and the sensible workaround, merging unrelated APIs into one documentation project, distorts the information architecture to fit the invoice.; Sphinx reStructuredText is harder to write than Markdown and puts off contributors, though MyST now allows Markdown
  • They diverge on capability: ReadMe covers OpenAPI reference, Sphinx covers Cross-references.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which ReadMe and Sphinx actually diverge.

Attributes where ReadMe and Sphinx differ
AttributeReadMeSphinx
Pricing modelPer project per monthOpen source, no licence fee
PlatformsWebLinux, macOS, Windows

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

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 ReadMe

  • OpenAPI reference
  • Try It playground
  • API metrics
  • Personalised docs
  • Versioning
  • Guides and recipes
  • Git sync via rdme
  • Changelog and support widget

Only in Sphinx

  • Cross-references
  • API autodoc
  • Multi-format output
  • Extension ecosystem

What people use each for

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

ReadMe

  • Publishing a public API reference where a developer can send a live request with their own key from the documentation pagenot Sphinx
  • Cutting support load by showing an integrating developer their own recent failing requests next to the endpoint descriptionnot Sphinx
  • Keeping documentation versions aligned with API versions so customers on an older release read the matching referencenot Sphinx
  • Shipping documentation from the same pull request as the code change using the rdme command line tool in CInot Sphinx

Sphinx

  • Large technical documentation needing reliable cross-referencesnot ReadMe
  • Python projects generating API docs from docstringsnot ReadMe
  • Documentation that must ship as PDF as well as HTMLnot ReadMe

Where each one falls short

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

ReadMe

  • Pricing is per project, so an organisation with several distinct APIs multiplies the monthly bill rather than adding seats, and the sensible workaround, merging unrelated APIs into one documentation project, distorts the information architecture to fit the invoice.
  • The metrics and personalisation features require your API to stream request logs to ReadMe, which means production request metadata leaves your infrastructure and needs a scrubbing layer plus a security review before anything is switched on.
  • Single sign-on and private documentation sit on the higher tier, so a company that only needs to gate partner documentation behind SAML pays a large step up for one control.
  • The platform is built for describing REST APIs, and long-form product manuals, internal knowledge bases or non-OpenAPI protocols fit it badly, so most customers end up running a second documentation tool alongside it.
  • Theming is bounded by ReadMe templates and limited custom CSS, so a documentation site that must match a strongly designed marketing site will not get there without compromise.
  • Content uses ReadMe-specific Markdown extensions and platform features, so migrating away is an export plus a rewrite rather than moving a folder of Markdown files.

Sphinx

  • reStructuredText is harder to write than Markdown and puts off contributors, though MyST now allows Markdown
  • Configuration is complex and the default output is dated-looking without theme work
  • Build times on large documentation sets are slow
  • Heavier than the problem for a small project that only needs a few pages

Pricing, plan by plan

ReadMe

Free
  • FreeFree
    • One project on a ReadMe subdomain
    • OpenAPI reference and guides
    • Basic editing and publishing
  • Startup$99/month
    • One project
    • Custom domain
    • API metrics from request logs
  • Business$399/month
    • One project
    • SAML single sign-on
    • Private and partner-only documentation
  • Enterprise$undefined/year
    • Multiple projects under one contract
    • Negotiated support and uptime terms
    • Security review and custom deployment questions

Sphinx

Free
  • SphinxFree
    • Full functionality
    • Commercial use permitted
    • Community support

Which should you pick?

Choose ReadMe if

  • You need openapi reference.
  • You want to start without paying.
  • You also want try it playground.
ReadMe review

Choose Sphinx if

  • You need cross-references.
  • You want to start without paying.
  • You work on Linux, macOS, Windows.
  • You also want api autodoc.
Sphinx review

Questions people ask

Is ReadMe or Sphinx better?
Neither clearly leads. ReadMe starts at Free and Sphinx at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, ReadMe or Sphinx?
ReadMe starts at Free and Sphinx at Free.
Does ReadMe or Sphinx run on more platforms?
ReadMe runs on Web. Sphinx runs on Linux, macOS, Windows.
Can I use ReadMe for free?
Both have a free tier, so you can try either at no cost before committing.
What is ReadMe best used for?
ReadMe is most often used for publishing a public api reference where a developer can send a live request with their own key from the documentation page, cutting support load by showing an integrating developer their own recent failing requests next to the endpoint description, keeping documentation versions aligned with api versions so customers on an older release read the matching reference, shipping documentation from the same pull request as the code change using the rdme command line tool in ci. Of those, publishing a public api reference where a developer can send a live request with their own key from the documentation page and cutting support load by showing an integrating developer their own recent failing requests next to the endpoint description are not what Sphinx is typically brought in for.
What can ReadMe do that Sphinx cannot?
ReadMe covers OpenAPI reference, Try It playground, API metrics, Personalised docs. Sphinx covers Cross-references, API autodoc, Multi-format output, Extension ecosystem.

Answered from the vendors’ own pages

ReadMe: Is ReadMe priced per user?

No. It is priced per project, meaning per documented API. Team size does not change the bill, and a second API generally does.

Sphinx: Is Sphinx free?

Yes, open source under the BSD licence.

ReadMe: Do I have to send my API logs to ReadMe?

Only for metrics and personalised documentation. The reference, guides and playground work without it, but the features that most distinguish the product are the ones that need the log stream.

Sphinx: Do I have to write reStructuredText?

Not any more. The MyST extension allows Markdown, though reStructuredText remains the native format and most examples use it.

ReadMe: Can I keep documentation in Git?

Yes. The rdme command line tool synchronises Markdown and OpenAPI files from a repository, so documentation can ship in the same pull request as the code.

Sphinx: Why do large projects choose Sphinx?

Automatic cross-referencing and API extraction from docstrings, which lighter generators do not provide.

ReadMe: Can I self-host it?

No. ReadMe is a hosted product only, so buyers with a hard on-premises requirement need a different platform.

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