Best API Documentation Tools in 2026
Updated
In short: Scalar is ranked #1 of 28 as of 4 October 2026, ahead of Javadoc and Doxygen. The best-ranked option with a free plan is Javadoc. The lowest first paid tier on this page is Redocly at $10/mo.
API documentation tools help present an API’s endpoints and supporting guidance for developers who need to understand or use an interface. Compared on interactive API reference, code samples, and OpenAPI import, the entries cover practical parts of documenting APIs. API versioning is another factor as interfaces change; custom domain and hosting model can help you assess how documentation fits your setup. Free plans and paid-from pricing offer cost context. Scalar, Doxygen, and Apiary are among the tools shown. Compare the listed capabilities with the documentation workflow and publishing approach you need.
28 API documentation tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
14 of the 25 here have a free tier you can use, 0 have open-source code on record, and 0 have full bars: free, open, on most of your devices and documented.
| # | App | Signal | Free tier | Open code | Devices | From | Score |
|---|---|---|---|---|---|---|---|
| 1 | ScalarWeb · Windows · Mac · Linux · Self-hosted · API | Three bars | — | 4 of 6 | $150/mo | 6.7 | |
| 2 | JavadocWeb · Windows · Mac · Linux | Three bars | — | 4 of 6 | Free | 6.6 | |
| 3 | DoxygenWindows · Mac · Linux | Three bars | — | 3 of 6 | Free | 6.5 | |
| 4 | ApiaryWeb · API | Two bars | — | 1 of 6 | Free | 6.4 | |
| 5 | ApiNotesWeb | Two bars | — | 1 of 6 | $19/mo | 6.4 | |
| 6 | MihariWeb | Two bars | — | 1 of 6 | €19/mo | 6.4 | |
| 7 | PaltWeb | Two bars | — | 1 of 6 | $19/mo | 6.4 | |
| 8 | PilotDocsWeb | Two bars | — | 1 of 6 | $49/mo | 6.4 | |
| 9 | Stoplight ElementsWeb · Self-hosted | Two bars | — | 1 of 6 | Free | 6.4 | |
| 10 | ZudokuWeb · Self-hosted | Two bars | — | 1 of 6 | Free | 6.4 | |
| 11 | FernWeb | Two bars | — | 1 of 6 | Free | 6.3 | |
| 12 | RapiDocWeb · Self-hosted | Two bars | — | 1 of 6 | Free | 6.3 | |
| 13 | ReadMeWeb | Two bars | — | 1 of 6 | $250/mo | 6.3 | |
| 14 | RedoclyWeb · API · Extension | One bar | — | — | 1 of 6 | $10/mo | 5.5 |
| 15 | Bump.shWeb · Self-hosted · API | One bar | — | — | 1 of 6 | $50/mo | 5.4 |
| 16 | phpDocumentorMac · Linux | No signal | — | — | 2 of 6 | — | 5.3 |
| 17 | TheneoWeb | One bar | — | — | 1 of 6 | — | 5.3 |
| 18 | DapperDoxWindows · Linux | No signal | — | — | 2 of 6 | — | 5.2 |
| 19 | EndrelWeb · API | One bar | — | 1 of 6 | ₹1,499/mo | 5.2 | |
| 20 | Swagger CodegenWeb | No signal | — | — | 1 of 6 | — | 5.2 |
| 21 | MiredotNo platforms listed | No signal | — | — | 0 of 6 | — | 5.1 |
| 22 | Swagger2MarkupNo platforms listed | No signal | — | — | 0 of 6 | — | 5.1 |
| 23 | WiddershinsNo platforms listed | No signal | — | — | 0 of 6 | — | 5.1 |
| 24 | JSDocNo platforms listed | No signal | — | — | 0 of 6 | — | 5.0 |
| 25 | OpenAPI 3 GeneratorNo platforms listed | No signal | — | — | 0 of 6 | — | 5.0 |
Is your app on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which API documentation tool is ranked first on Freedom251?
Scalar is ranked #1 of 28 with a score of 6.7. Javadoc is second and Doxygen third.
How many of these have a free plan?
14 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Redocly has the lowest first paid tier we found: $10/mo.
How is this list ranked?
Ranked free-and-open first: a usable free tier and open-source code, then the platforms it runs on and its documentation. Paid placements never change a rank.