Free Mock APIs & Test Data Services (2026)

Free fake REST API for prototyping, mock posts, comments, todos, and users with zero configuration.

A hosted REST-API ready to respond to your AJAX requests with simulated realistic user and auth data.

Free dummy REST API with products, carts, users, posts, comments, auth, and image placeholder endpoints.

Public directory and queryable dataset of over 9,000 accredited universities and domains worldwide.

Free, persistent key-value counter API to track page views, hits, and downloads without creating a database.

Predict someone's age from their first name based on international census records and demographic modeling.

Predict gender from first name with international probability scores and database of over 100M profiles.

Estimate nationality and origin country probabilities from given names using statistical country data.

Free API for generating realistic placeholder user data with photos, names, emails, and address models.

HTTP client testing service with endpoints for inspecting headers, status codes, methods, and payloads.

Inspect HTTP requests and webhooks with real-time payload logging and debugging.

Echo service to test REST clients, authorization headers, digest auth, and query parameters.

Free cloud storage for JSON data, ideal for prototyping frontend applications with mock backends.

Generate custom HTTP responses with custom bodies, headers, and status codes with zero backend setup.

Create mock API endpoints in 5 seconds to test incoming webhooks, payloads, and simulated responses.

Query Wikidata's linked open database using SPARQL queries to extract structured facts and entities.

Free HTTP microservice to generate customizable high-resolution QR codes on the fly in PNG and SVG.

Malicious URL feed and threat intelligence database for automated cybersecurity scanning.

K-anonymity search API checking password hashes against billions of compromised breach credentials securely.

GitHub API endpoint returning metadata, permissions, and conditions for popular open source licenses.

Predict gender from first name with probability scores and count statistics.

Predict age from first names based on statistical demographic modeling.

Predict nationality from names returning top country codes and confidence scores.

Queryable directory of hundreds of free public APIs categorized by topic and authentication requirements.

Screenshot API: one GET request renders a URL, HTML, or Markdown to PNG, JPEG, WebP, PDF, or scrolling video (MP4/WebM/GIF), with full-page and element capture, device presets, dark mode, and ad/cookie-banner blocking. Free plan: 100 screenshots/month that resets monthly, no credit card.

Find the best GTM APIs. Benchmarking GTM APIs with published results at datacircle.dev. Base URL https://api.datacircle.dev/v1.