OpenAPI / Swagger Viewer
Paste an OpenAPI/Swagger spec (JSON or YAML) — live summary, endpoint browser with filters, validation warnings, and Markdown export.
About this ToolHow it works, benefits & use casesTap to collapse
Drop an OpenAPI or Swagger specification — in either JSON or YAML — and explore it without spinning up Swagger UI. The viewer sniffs the format, converts YAML to JSON when needed, and parses the spec into a tidy summary: API title, version, description, server URLs, total endpoint and schema counts, and a breakdown of endpoints by HTTP method. Below that is a searchable, filterable endpoint browser; each operation shows a colour-coded method badge, its path, summary and tags, and you can narrow the list by method or by typing into the filter. The spec is validated as you go, with warnings for things like missing responses, missing info fields, or paths that do not start with a slash. Finally, the tool generates Markdown documentation grouped by tag that you can copy, download, share via URL, or pipe onward. A built-in Pet Store example loads instantly.
How to Use
- 1Paste your OpenAPI/Swagger spec (JSON or YAML) into the editor, or click "Load example" for a Pet Store demo.
- 2Click "Parse specification"; the API summary appears with title, version, endpoint and schema counts and per-method chips.
- 3Review any validation warnings or errors shown beneath the summary.
- 4Use the endpoint browser: filter by path or summary text, and narrow by HTTP method with the dropdown.
- 5Copy, download, or share the auto-generated Markdown docs from the output panel.
Key Benefits
- Accepts both JSON and YAML specs, auto-detecting and converting YAML as needed
- Summary with title, version, description, servers, and endpoint/schema counts
- Searchable, method-filterable endpoint browser with colour-coded method badges and tags
- Validation surfaces missing responses, missing info fields and malformed paths
- Generates tag-grouped Markdown documentation from the spec
- Live parsing as you edit, with the detected input format and character count shown
- Shareable URL and pipe-to-tool support; runs entirely in the browser
Common Use Cases
- Quickly browsing an unfamiliar API’s endpoints without standing up Swagger UI
- Generating Markdown API docs to paste into a README or wiki
- Filtering a large spec down to just the POST or DELETE operations during review
- Validating a hand-edited spec for missing responses or info fields before publishing
- Sharing a parsed view of a spec with a teammate via a single URL
0 characters · JSON or YAML
Was this tool helpful?
Share Your Experience
Help others discover this tool!
Related tools
- JSON FormatterFormat and validate JSON with syntax highlighting
- YAML to JSONConvert YAML to JSON format
- Intersection Observer GeneratorGenerate IntersectionObserver code from a use-case picker (reveal, lazy-load, infinite scroll, scroll-spy, sticky, video autoplay) with a live trigger-zone diagram and vanilla/React/Vue output
- API Documentation GeneratorGenerate API documentation from endpoints
- cURL to Code ConverterConvert cURL commands to code in various languages
- GraphQL Schema ValidatorValidate GraphQL schema definitions
Both. If the input does not start with { or [, the viewer attempts a YAML-to-JSON conversion before parsing, and it also retries as YAML if a JSON parse fails. The detected format (JSON or YAML) is shown in the input description so you can confirm how it was read.
It reads specs that declare either an openapi field (OpenAPI 3.x) or a swagger field (Swagger 2.0). It extracts info, servers, paths and component schemas; a document without an openapi or swagger version field is reported as not a valid specification.