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OpenAPI Viewer

Parse an OpenAPI 3.x or Swagger 2.0 document in JSON or YAML and render its structure in the browser.

  • Runs locally in your browser
  • No upload required

Try it

Paste JSON or YAML. It is parsed in your browser and never uploaded.

Format
JSON
Specification
OpenAPI 3.1.0
Title
Items API
API version
1.0.0
Servers
0
Paths
1
Operations
1
Tags
0
Component schemas
0
Operation list
GET /items
{
  "format": "json",
  "specVersion": "3.1.0",
  "kind": "OpenAPI",
  "title": "Items API",
  "apiVersion": "1.0.0",
  "servers": 0,
  "paths": 1,
  "operations": [
    {
      "method": "GET",
      "path": "/items"
    }
  ],
  "operationCount": 1,
  "tags": 0,
  "schemas": 0,
  "problems": [],
  "selected": [
    {
      "method": "GET",
      "path": "/items"
    }
  ]
}

Supported formats

Input
text, select
Output
text, json

Privacy

Runs entirely in your browser. Your input is never uploaded, stored, or sent to a third party.

Processing
In your browser
Privacy level
Browser only

Parsed OpenAPI 3.1.0 "Items API" with 2 path(s) and 3 operation(s).

How it works

  • Detected JSON input and parsed the document.
  • Read the OpenAPI version 3.1.0 and the info block.
  • Counted 1 server(s), 2 path(s), 3 operation(s), 0 tag(s) and 0 component schema(s).
  • Listed every operation.
  • No structural problems were found in the parts this viewer reads.
  • The viewer does not resolve external $ref targets or fetch a remote document.

Methodology

  1. Detect JSON by a leading brace or bracket; otherwise parse the text as YAML with the JSON↔YAML engine.
  2. Require an `openapi` (3.x) or `swagger` (2.0) version field; otherwise reject as unrecognised.
  3. Read `info.title` and `info.version` and record a note when either is missing.
  4. Count servers (or the Swagger host), paths, operations, tags and component/definition schemas.
  5. List the operations as METHOD + path and filter them by the optional path fragment.

Usage

  1. Paste an OpenAPI 3.x or Swagger 2.0 document as JSON or YAML.
  2. Optionally type a path fragment to filter the operation list.
  3. Read the version, info, counts, operation list and any structural notes.

Examples

These are examples, not current values: they use fixed inputs, while the interactive tool computes live results in your browser.

OpenAPI 3.1 JSON document

jsonSelect to copy
{
  "text": "{\"openapi\":\"3.1.0\",\"info\":{\"title\":\"Items API\",\"version\":\"1.2.0\"},\"servers\":[{\"url\":\"https://api.example.com\"}],\"paths\":{\"/items\":{\"get\":{\"responses\":{\"200\":{\"description\":\"ok\"}}},\"post\":{\"responses\":{\"201\":{\"description\":\"created\"}}}},\"/items/{id}\":{\"get\":{\"responses\":{\"200\":{\"description\":\"ok\"}}}}}}",
  "path": ""
}

Swagger 2.0 YAML document

jsonSelect to copy
{
  "text": "swagger: \"2.0\"\ninfo:\n  title: Legacy API\n  version: \"1.0\"\nhost: api.example.com\npaths:\n  /ping:\n    get:\n      responses:\n        \"200\":\n          description: ok\n",
  "path": "/ping"
}

Limitations

What a viewer should and should not do

An OpenAPI document describes an API, so it is often as sensitive as the API itself. A viewer that uploads the document to a service leaks internal host names and schema shapes. This viewer parses the text locally and shows the structure; it deliberately refuses to fetch a URL or follow an external reference, because that would turn a viewing action into a network request.

Structure, not full validation

Full OpenAPI validation is a large specification concern and usually needs a schema dialect and reference resolution. This tool answers a narrower, honest question: can the document be read as OpenAPI, and what does it contain? It reports missing version or info fields and leaves deep schema validation to a dedicated tool.

Frequently asked questions

Is my API document uploaded?
No. The document is parsed entirely in your browser. It is never sent, stored or logged, which matters because an API description often names internal hosts.
Does it validate my schema?
It performs structural checks (version, info, paths) and reports problems with the parts it reads. It is not a full JSON Schema or OpenAPI validator, and it does not resolve remote references.
Which versions are supported?
OpenAPI 3.x (via the openapi field) and Swagger 2.0 (via the swagger field). The version string is reported as written.

Sources

  1. OpenAPI Specification 3.1.0 — OpenAPI Initiative
  2. OpenAPI Specification 2.0 (Swagger) — OpenAPI Initiative
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