ReDoc Viewer – View OpenAPI Documentation Online
The ReDoc Viewer is a free, browser-based tool that renders OpenAPI and Swagger specifications as beautiful, three-panel API documentation using ReDoc. Paste, upload, or link your spec to generate clean, readable docs instantly.
ReDoc Viewer
Note: The URL must be publicly accessible and allow cross-origin requests (CORS).
Drop your OpenAPI file here
or click to browse (.json, .yaml, .yml)
What is ReDoc?
ReDoc is a popular open-source tool for generating beautiful, responsive API documentation from OpenAPI (Swagger) specifications. Unlike interactive API explorers, ReDoc focuses on producing clean, readable documentation that's ideal for publishing and sharing with developers.
This free online ReDoc Viewer lets you render any OpenAPI 3.x or Swagger 2.0 specification instantly. Simply paste your spec, upload a file, or load from a URL—no signup or installation required.
When to Use ReDoc
- Publishing API references: Generate polished documentation for developer portals.
- Reviewing spec changes: Quickly visualize how API updates affect your docs.
- Sharing with stakeholders: Provide clean, readable API overviews without technical setup.
- Embedding in websites: Preview how ReDoc will render before integrating it into your site.
How This Compares to Other Tools
This ReDoc Viewer focuses on rendering clean, readable API documentation. Tools like Swagger Editor are designed for manual specification editing, while Postman focuses on API testing and collaboration. ReDoc specializes in presenting OpenAPI definitions as polished documentation, making it ideal for publishing and sharing API references. For interactive API exploration and testing, consider using a Swagger Viewer.
Related Tools
OpenAPI Builder
Create OpenAPI specifications from scratch using a form-based interface. No YAML or JSON knowledge required.
Swagger Viewer
Explore and test API endpoints interactively using Swagger UI. Ideal for developers who want to try out API calls.
JSON Formatter
Format, validate, and beautify JSON data instantly. Perfect for cleaning up API responses and spec files.
Frequently Asked Questions
ReDoc is a powerful open-source documentation generator created by Redocly. It takes your OpenAPI (formerly Swagger) specification file and transforms it into a beautiful, responsive, three-panel documentation layout. The left panel shows navigation, the middle panel displays endpoint details, and the right panel provides code samples. It's designed specifically for publishing polished API references that developers love to read.
Absolutely! This online ReDoc Viewer is 100% free to use with no limitations whatsoever. There's no account required, no email signup, no premium tiers, and no usage caps. Everything runs directly in your browser using JavaScript, which means your API specification never leaves your computer—it's never uploaded to our servers or stored anywhere.
Yes, full support for both! This viewer handles OpenAPI 3.0, OpenAPI 3.1, and the older Swagger 2.0 format (now called OpenAPI 2.0). You can paste or upload your specification in either JSON or YAML format—the tool automatically detects which one you're using and parses it accordingly.
The key difference is interactivity vs. readability. Swagger UI is an interactive explorer—it lets you fill in parameters and actually execute API calls right from the documentation. ReDoc, on the other hand, is optimized purely for reading. It produces cleaner, more polished documentation that's perfect for public-facing developer portals, embedded product docs, or generating PDFs. If you need to test endpoints, use Swagger UI. If you need to publish beautiful docs, use ReDoc.