How to View OpenAPI Specifications

View and explore OpenAPI (Swagger) specifications online. Free OpenAPI viewer for REST API documentation. Supports OpenAPI 3.x and Swagger 2.0.

Open OpenAPI Spec Viewer →

Step-by-Step Guide

1

Get your OpenAPI spec

Obtain your OpenAPI specification file in JSON or YAML format. You can also use a URL pointing to a publicly accessible spec file, or paste the raw content directly.

2

Load the spec

Paste your OpenAPI spec into the input area, or enter the URL. The tool automatically detects whether it is JSON or YAML and parses it accordingly.

3

Explore the API documentation

The viewer renders your spec as interactive documentation. Browse endpoints by tag or path, view request/response schemas, see authentication requirements, and examine parameter details.

4

Test endpoints (if enabled)

Some OpenAPI viewers allow you to test endpoints directly from the documentation. Enter authentication credentials and parameter values, then send requests to see live responses.

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No signup, no download. Runs entirely in your browser.

Open OpenAPI Spec Viewer

Frequently Asked Questions

What is OpenAPI?
OpenAPI Specification (formerly Swagger) is a standard format for describing REST APIs. It defines endpoints, methods, parameters, request/response schemas, authentication, and more in a machine-readable format.
What versions are supported?
This viewer supports OpenAPI 3.0, 3.1, and Swagger 2.0 (OpenAPI 2.0). Older formats may work but are not guaranteed.
Can I use this for internal APIs?
Yes. Since the viewer runs entirely in your browser, you can safely view internal API specs without sending data to external servers. Just paste the spec content directly.
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