Dev tools · alternatives · 2026

24 alternatives to Open-source Swagger/OpenAPI documentation engine

📘 OpenAPI/Swagger-generated API Reference Documentation - Redocly/redoc

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Open-source Swagger/OpenAPI documentation engine launched in 2016; newer entries below may have overtaken it.

1
Swagger Editor▲207
Beautiful API references from Swagger, OpenAPI spec
2023 · sandbox.scalar.com · its alternatives →
2
Mitmproxy2swagger – Automagically reverse-engineer REST APIs▲691
Automagically reverse-engineer REST APIs via capturing traffic - alufers/mitmproxy2swagger
2022 · github.com · its alternatives →
3
A faster way to prototype your APIs using OpenAPI 3 and Swagger UI▲77
A generator for OpenAPI 3. Contribute to egorsmkv/openapi3-generator development by creating an account on GitHub.
2020 · github.com · its alternatives →
4
OpenAPI DevTools – Chrome extension that generates an API spec▲811
Effortlessly discover API behaviour with a Chrome extension that automatically generates OpenAPI specifications in real time for any app or website.
2023 · github.com · its alternatives →
5
Swagger Inspector▲141
Free online tool to test APIs and autogenerate documentation
2018 · swagger.io · its alternatives →
6
Docs by Hashnode▲700
The gold standard for your API references and product guides
2024 · hashnode.com · its alternatives →
7
Nuxt.js OpenAPI / Swagger API Reference Documentation▲5
2024 · github.com · its alternatives →
8
Open-source tool to generate OpenAPI docs from your code▲11
We built an open-source tool that scans your codebase and generates OpenAPI docs in minutes. Right now it supports Rails, Go, Python, and NodeJS frameworks, and we will keep adding more. It picks up routes, params, request bodies, and models directly from the code and outputs a clean OpenAPI spec you can drop into your workflow.
Nov 2025 · github.com · its alternatives →
9
Swag Doc▲8
automatically generate swagger documentation from api.
2025 · github.com · its alternatives →
10
create-api.dev by Kong▲150
Generate and share OpenAPI specs with AI
2025 · api.dev · its alternatives →
11
Refraction▲156
Generate unit tests, create docs and refactor code using AI.
2023 · refraction.dev · its alternatives →
12
Simple API Generator (Rest + GraphQL)▲121
Instantly generate openapi (OAS) 3.0.0 REST + GraphQL APIs
2019 · github.com · its alternatives →
13
Swagger Codegen▲29
Auto-generate API clients, server stubs, docs for REST APIs
2017 · github.com · its alternatives →
14
Agents.json – OpenAPI Specification for LLMs▲212
Hey HN, we’re building an open specification that lets agents discover and invoke APIs with natural language, built on the OpenAPI standard. agents.json clearly defines the contract between LLMs and API as a standard that's open, observable, and replicable. Here’s a walkthrough of how it works: https://youtu.be/kby2Wdt2Dtk?si=59xGCDy48Zzwr7ND. There’s 2 parts to this: 1. An agents.json file describes how to link API calls together into outcome-based tools for LLMs. This file sits alongside an OpenAPI file. 2. The agents.json SDK loads agents.json files as tools for an LLM that…
2025 · github.com · its alternatives →
15
Auto-generate an OpenAPI spec by listening to localhost▲178
Hey HN! We've developed OpenAPI AutoSpec, a tool for automatically generating OpenAPI specifications from localhost network traffic. It’s designed to simplify the creation of API documentation by just using your website or service, especially useful when you're pressed for time. Documenting endpoints one by one sucks. This project originated from us needing it at our past jobs when building 3rd-party integrations. It acts as a local server proxy that listens to your application’s HTTP traffic and automatically translates this into OpenAPI 3.0 specs, documenting endpoints, requests, and…
2024 · github.com · its alternatives →
16
doks.io▲8
Generate API documentation automatically
2025 · its alternatives →
17
Visual Swagger Editor for Teams▲89
Link your app design to API calls
2022 · its alternatives →
18
OpenAPI Editor▲7
Easily edit OpenAPI and Swagger files in JetBrains products
2020 · plugins.jetbrains.com · its alternatives →
19
Swagify.io▲8
Convert Postman Collection to Swagger/Open API Spec
2023 · its alternatives →
20TA
TypeAPI – An OpenAPI alternative optimized for code generation▲55
An OpenAPI alternative to describe REST APIs for type-safe code generation.
2023 · typeapi.org · its alternatives →
21
Turn your OpenAPI spec into negative tests▲50
I’ve been working on an open-source CLI tool called Dochia for a while now. The reason for building it: in microservices architectures, testing is repetitive: every service exposes APIs, and much of the testing process will share a similar set of test cases: negative inputs, boundary cases, encoding quirks, invisible characters. I wanted a tool that could automate this shared layer of testing instead of doing it manually across dozens of services. So what Dochia does: reads your OpenAPI spec; generates thousands of smart, edge-case payloads automatically and produces detailed reports with…
2025 · github.com · its alternatives →
22
Guide▲9
Let your API speak for itself, OpenAPI to beautiful docs.
2025 · rafaelneves.me · its alternatives →
23
Scrape to Swagger – webscraper for API documentation▲6
Scrape API Documentation from HTML to a JSON Swagger Document - rbren/scrape-to-swagger
2016 · github.com · its alternatives →
24
Generates Golang client and server based on Swagger definitions▲5
Generates Golang client and server based on OpenAPI2 (swagger) definitions - ExperienceOne/apikit
2020 · github.com · its alternatives →

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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →