APIs.guru API

Beginner's Pick Development / No Auth Required Beginner HTTPS
Free to Use
70 B
Measured Score 0 50 100 Speed 7/30 Consistency 20/20 Security 20/20 Browser access 15/15 Transparency 8/15 TESTED 2026-08-10

Overview

APIs.guru maintains a crowd-sourced directory of OpenAPI (Swagger) specification files for hundreds of public web APIs, all normalized to OpenAPI 3.0 format. The API lets you fetch a full machine-readable catalog of API specs that you can use to auto-generate client SDKs, documentation, or test harnesses. It is often called the "Wikipedia for APIs" and is a go-to resource for API tooling and discovery.

Beginner Tip

No API key is required — start by calling https://api.apis.guru/v2/list.json to get the full catalog as a JSON object keyed by provider domain. Each provider entry links to the actual OpenAPI spec URL which you can then fetch and parse with any OpenAPI library.

Measurement Record

What actually happened when we called this API from our own infrastructure. Every value below was recorded by the request, not copied from the provider's documentation.

Request
GET https://api.apis.guru/v2/list.json
Result
HTTP 200 · application/json · 8,855,894 bytes · compressed
Response time
469 ms (median of 3) · fastest 462 ms
Transport
TLSv1.3 · TLS_AES_256_GCM_SHA384 · certificate issued by Google Trust Services
Browser CORS
Allowed — Access-Control-Allow-Origin: *
Served by
cloudflare
Recorded
2026-08-10

Available Data

The kind of data this API exposes, based on its documentation. We could not call the endpoint to confirm the exact field names.

APIs.guru data via REST API

Example Response

Illustrative shape only — we were not able to call this endpoint (it requires credentials or exposes no public sample URL), so the fields below show the kind of data this API returns rather than a recorded response.

JSON Response · Illustrative
{
  "status": "success",
  "data": {
    "result": "Data from APIs.guru",
    "description": "Wikipedia for Web APIs, OpenAPI/Swagger specs for public APIs",
    "timestamp": "2025-01-15T10:00:00Z"
  }
}

Field Reference

{provider}.apis.{version}.info.title Human-readable title of the API at this version.
{provider}.apis.{version}.info.version Version string of the API spec.
{provider}.apis.{version}.swaggerUrl Direct URL to the OpenAPI JSON spec file for this version.
{provider}.apis.{version}.updated ISO 8601 timestamp when this spec was last updated in the catalog.
{provider}.preferred Version string of the recommended version to use for this provider.

Implementation Example

Calls a real endpoint of this API. Replace any placeholder credentials with your own key.

Request
const url = "https://api.apis.guru/v2/list.json";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

How This API Fails

We deliberately sent this API a broken request and recorded exactly what came back on 2026-08-10. Knowing the shape of an error before you hit it makes error handling much easier to write.

HTTP 404 Requesting a path that does not exist text/html

Returned an HTML error page rather than JSON — worth knowing if your client assumes every response can be parsed as JSON.

Common Errors & Troubleshooting

Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.

Response is a large JSON object (several MB) The /list.json endpoint returns metadata for hundreds of APIs at once.
Filter by provider name client-side after fetching, or use the /providers.json endpoint first to get just the list of provider names.
OpenAPI spec URL returns 404 or outdated content Third-party API providers occasionally change or remove their spec files.
Check the updated field in the API entry to see when the spec was last verified; use the preferred.spec_url from the API entry.
Parsing errors on fetched OpenAPI specs Not all specs in the catalog strictly conform to the OpenAPI 3.0 standard.
Use a lenient OpenAPI parser that can handle minor spec violations, such as swagger-parser with options.validate.schema set to false.

Measured Score Breakdown

Live HTTP request to the API endpoint

Speed 7/30
Consistency 20/20
Security 20/20
Browser access 15/15
Transparency 8/15
Endpoint Response Time 469ms

Fully tested on Aug 10, 2026

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS UNKNOWN
Category Development
Difficulty Beginner
Endpoint last called: 2026-08-10

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