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OpenAPIFree · Runs in browser

OpenAPI Viewer

Explore OpenAPI / Swagger specs — paths, operations, schemas, and security.

Quick answer

OpenAPI Viewer on space4.dev is a free online openapi tool. Explore OpenAPI / Swagger specs — paths, operations, schemas, and security. It runs entirely in your browser — no signup, no install, and your data is not uploaded to our servers.

Price
Free
Signup
Not required
Processing
100% in your browser
Data uploaded
No
Best for
openapi viewer, swagger viewer, openapi explorer

Features

  • Paste or upload JSON / YAML / YML
  • Auto-detect format and OpenAPI version
  • Browse servers, tags, paths, and schemas
  • Filter by HTTP method and search endpoints
  • Copy endpoint and download as JSON or YAML
  • Expand/collapse schema details

Examples

Minimal OpenAPI 3.1
{"openapi":"3.1.0","info":{"title":"Demo","version":"1.0.0"},"paths":{}}

Frequently asked questions about OpenAPI Viewer

Quick answers for privacy, pricing, and how this free online tool works.

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Guide

OpenAPI Viewer — complete guide

What is an OpenAPI Viewer?

OpenAPI (and older Swagger 2.0) documents describe HTTP APIs: paths, methods, parameters, schemas, and security. An OpenAPI viewer helps humans explore that document without reading raw YAML line by line.

space4.dev’s OpenAPI Viewer parses JSON or YAML in the browser, lists endpoints, filters by HTTP method, and lets you inspect schemas and security schemes privately.

How to explore an OpenAPI spec

Workflow:

  • Paste an OpenAPI/Swagger document or upload a .json / .yaml / .yml file.
  • Review title, version, servers, and tags in the overview.
  • Search or filter paths (GET, POST, PUT, PATCH, DELETE, …).
  • Open the Schemas tab to expand component models.
  • Download JSON or YAML if you need a cleaned copy for your repo.

Review internal APIs safely

Internal OpenAPI files often reveal unreleased endpoints. Client-side viewing means you can review them on a plane or a locked-down laptop without uploading the spec to a SaaS documentation host.