Documentation · head to head
Sphinx vs Read the Docs
Sphinx
Documentation
Documentation generator built for large technical projects
- From
- Free
- Rated
- -
Read the Docs
Documentation
Documentation hosting with versioning built for open source
- From
- Free
- Rated
- -
The short version
- Each has a real cost: Sphinx reStructuredText is harder to write than Markdown and puts off contributors, though MyST now allows Markdown; Read the Docs build configuration is finicky, and build failures on dependency changes are a common frustration
- They diverge on capability: Sphinx covers Cross-references, Read the Docs covers Build on commit.
Where they differ
Only the attributes on which Sphinx and Read the Docs actually diverge.
| Attribute | Sphinx | Read the Docs |
|---|---|---|
| Pricing model | Open source, no licence fee | Free for open source; paid business plans for private documentation |
| Platforms | Linux, macOS, Windows | Web, Cloud |
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 Sphinx
- Cross-references
- API autodoc
- Multi-format output
- Extension ecosystem
Only in Read the Docs
- Build on commit
- Version by branch and tag
- Pull request previews
- Free for open source
What people use each for
The jobs each tool is most often brought in to do.
Sphinx
- Large technical documentation needing reliable cross-referencesnot Read the Docs
- Python projects generating API docs from docstringsnot Read the Docs
- Documentation that must ship as PDF as well as HTMLnot Read the Docs
Read the Docs
- Open-source projects needing free hosted versioned documentationnot Sphinx
- Teams wanting docs rebuilt automatically on every commitnot Sphinx
- Reviewing documentation changes in a pull request before mergenot Sphinx
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
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
Read the Docs
- Build configuration is finicky, and build failures on dependency changes are a common frustration
- Default themes are recognisable and dated, so sites look alike unless customised
- Private documentation requires a paid business plan
- Build times on large projects are slow enough to interrupt a review cycle
Pricing, plan by plan
Sphinx
Free- SphinxFree
- Full functionality
- Commercial use permitted
- Community support
Read the Docs
Free- FreeFree
- Core functionality
- Public projects
Which should you pick?
Choose Sphinx if
- You need cross-references.
- You want to start without paying.
- You work on Linux, macOS, Windows.
- You also want api autodoc.
Choose Read the Docs if
- You need build on commit.
- You want to start without paying.
- You work on Web, Cloud.
- You also want version by branch and tag.
Questions people ask
- Is Sphinx or Read the Docs better?
- Neither clearly leads. Sphinx starts at Free and Read the Docs at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Sphinx or Read the Docs?
- Sphinx starts at Free and Read the Docs at Free.
- Does Sphinx or Read the Docs run on more platforms?
- Sphinx runs on Linux, macOS, Windows. Read the Docs runs on Web, Cloud.
- Can I use Sphinx for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Sphinx best used for?
- Sphinx is most often used for large technical documentation needing reliable cross-references, python projects generating api docs from docstrings, documentation that must ship as pdf as well as html. Of those, large technical documentation needing reliable cross-references and python projects generating api docs from docstrings are not what Read the Docs is typically brought in for.
- What can Sphinx do that Read the Docs cannot?
- Sphinx covers Cross-references, API autodoc, Multi-format output, Extension ecosystem. Read the Docs covers Build on commit, Version by branch and tag, Pull request previews, Free for open source.
Answered from the vendors’ own pages
Sphinx: Is Sphinx free?
Yes, open source under the BSD licence.
Read the Docs: Is Read the Docs free?
Free for open-source public projects. Private documentation requires a paid business plan.
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.
Read the Docs: What does it build from?
Most commonly Sphinx or MkDocs sources kept in your repository.
Sphinx: Why do large projects choose Sphinx?
Automatic cross-referencing and API extraction from docstrings, which lighter generators do not provide.
Read the Docs: How does versioning work?
It maps branches and tags to documentation versions, so several releases are served side by side without manual work.