Is there a limit on how many times I can use this tool?

No limits at all! You can use this Swagger/OpenAPI Viewer unlimited times, 24/7. Since all processing happens in your browser (client-side), there are no server requests that could be rate-limited.

Can I view OpenAPI and Swagger files online without Swagger UI?

Yes. An online Swagger and OpenAPI viewer allows you to paste JSON or YAML specifications and explore API endpoints directly in the browser without installing Swagger UI.

Swagger Viewer and OpenAPI Viewer Online

The best free Swagger & OpenAPI viewer. View, explore, and generate code from your API documentation. Supports JSON, YAML, OpenAPI 3.0 & Swagger 2.0.

✨ JSON/YAML Support 🔍 Search Endpoints 💻 Try It Out 📤 Official Swagger UI

🛡️ Browser-Based 🔒 Privacy Guaranteed 🎁 Free Forever

⭐ Tip: Bookmark this Swagger Viewer (Ctrl+D / ⌘+D) for quick access!

👇 Scroll down to use the tool

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Why Use This Swagger Viewer?

Need to quickly view API documentation without installing software or signing up? This online Swagger viewer lets you paste or load any OpenAPI/Swagger JSON or YAML file and explore it instantly — zero setup required.

No Installation: Works directly in your browser
JSON & YAML: Supports both formats automatically
Try It Out: Make live API calls with official Swagger UI
100% Private: Your specs never leave your device

OR paste your spec below

✨ ✨ Create/Edit OpenAPI Spec (Builder) 🚀 Validate JSON 📖 ReDoc Viewer

Loading Swagger UI...

Swagger Viewer Online (No Installation Required)

This swagger viewer online provides a complete environment to visualize your API documentation without downloading any software. Unlike local setups that require Node.js, Docker, or complex config files, this tool runs entirely in your browser.

Simply paste your specification or load a URL, and our browser based swagger ui will render it instantly. It's the fastest way to preview changes or share API details with team members who don't have development environments set up.

OpenAPI Viewer for JSON and YAML Files

Whether you're working with the legacy swagger json viewer format or modern openapi viewer specifications, this tool handles it all. It automatically detects and parses both JSON and YAML content.

It supports the full range of specifications, acting as a reliable openapi json viewer and openapi yaml viewer. Switching between formats is seamless—just paste the new code and click parse.

Swagger Viewer vs Swagger Editor

A Swagger Viewer is designed for consumption—reading docs, testing endpoints, and understanding the API. A Swagger Editor is for creation. Use this viewer when you need a lightweight, fast way to read specs without the heavy editing interface.

Swagger Viewer vs Postman

Postman is a powerful testing client but requires installation and accounts. This swagger ui online tool offers an instant "Try It Out" experience directly from your spec file, perfect for quick verify-and-go workflows.

Swagger Viewer vs Redoc

Redoc focuses on clean, read-only API documentation. This Swagger Viewer supports interactive "Try It Out" requests, making it better for testing and exploring APIs directly from the spec.

How to View Swagger JSON Online

To view swagger file online, simply open your JSON file in any text editor, copy the content, and paste it into our viewer. Alternatively, if your swagger json viewer file is hosted (e.g., on GitHub or a staging server), just paste the URL to load it dynamically.

The viewer resolves references and renders the interactive documentation immediately, allowing you to test endpoints right away.

How to View OpenAPI YAML Online

YAML is often preferred for its readability. To view openapi file online in YAML format, use the same input box. Our parser specifically handles indentation-sensitive YAML content, making it a robust openapi yaml viewer.

Swagger UI Online – Browser-Based Viewer

This tool provides a full swagger ui online experience. It uses the official Swagger UI library to ensure 100% compatibility with the standard. You get the same familiar interface, including the "Authorize" button, parameter inputs, and response visualization.

If you are looking for swagger ui without installation, this is the perfect solution. It works on Windows, Mac, Linux, and even mobile browsers.

What Is OpenAPI?

The OpenAPI Specification (formerly Swagger) is the industry standard for REST API definition. An openapi documentation viewer allows developers and stakeholders to visualize these definitions.

OpenAPI 3.0 vs OpenAPI 3.1

Our viewer supports both. The openapi 3.0 viewer functionality covers most existing APIs, while our openapi 3.1 viewer support handles the latest features like webhooks and full JSON Schema compatibility.

Swagger UI Example Using OpenAPI JSON

Example of initializing Swagger UI with an OpenAPI JSON file:

SwaggerUIBundle({
  url: "/openapi.json",
  dom_id: "#swagger-ui"
});

Related Developer Tools

Explore more free developer tools to work with JSON, APIs, and data formats:

Swagger Viewer FAQ

What is OpenAPI/Swagger? +

OpenAPI (formerly known as Swagger) is an industry-standard specification for describing, producing, consuming, and visualizing RESTful web services. It provides a way to describe your API's structure in a format that both humans and machines can understand.

What's the difference between OpenAPI 2.0 and 3.0? +

OpenAPI 3.0 introduced several improvements over 2.0 (Swagger):

• Simplified structure: Components section replaces definitions, parameters, responses
• Request body: Dedicated requestBody keyword instead of body parameters
• Multiple content types: Better support for different media types
• oneOf/anyOf/allOf: Enhanced schema composition

What file formats are supported? +

This viewer supports both JSON and YAML formats. You can paste your specification in either format, and the tool will automatically detect and parse it. You can also load specifications directly from a URL.

Is my API specification data stored? +

No, absolutely not! We use a zero-knowledge approach where all parsing is executed locally within your session. Your sensitive API documentation never leaves your machine.

Is this Swagger viewer completely free? +

Yes, 100% free! No account needed, no trial periods, no hidden costs. Use it for any spec size, as often as you want commercial or personal projects alike.

Does the "Try it out" feature work? +

Yes! This viewer uses the official Swagger UI library, so the "Try it out" feature is fully functional. You can make real API calls directly from the browser (subject to CORS restrictions on the target API).

Can I use this Swagger Viewer without logging in? +

Yes. This is a free Swagger viewer with no login. You can view OpenAPI and Swagger files online instantly without creating an account or uploading data to a server.

💡 About This Tool

Built for developers who need a quick way to explore REST APIs, this viewer uses the official Swagger UI library to render OpenAPI specs instantly. Paste JSON or YAML, or fetch from a URL. Everything runs locally your specifications stay on your machine. If you need to format raw list data for your API endpoints, try our Comma Separator Online.