Abacus
Development
Free and simple counting service. You can use it to track page hits and specific events
No keyCORSHTTPS
Free public APIs that actually work
Search 3,000+ tested public APIs and mock data feeds for fast prototyping. Instant filters for no-auth endpoints, browser-ready CORS support, and active HTTPS. Health-checked every 24 hours to weed out dead links and broken endpoints.
- APIs indexed
- 3,005
- No key needed
- 1,163
- CORS enabled
- 837
- Categories
- 58
Start here
Filter by development environment and authentication limits.
APIs with no key required
1,163 APIsCall endpoints straight away with cURL or frontend scripts. No signup forms, dashboard tokens, or config credentials required.
Works directly in the browser
392 APIsCORS-friendly endpoints with permissive origin headers. Query them directly from React, Vue, or static vanilla HTML files without a backend proxy.
Best for learning & portfolio projects
887 APIsPredictable schemas and clean JSON payloads. Recommended for tutorials, coding bootcamps, and frontend portfolio projects.
Free developer utilities & mock data
156 APIsFake REST payloads, dummy user databases, placeholder images, and status monitors. Zero-cost tooling for scaffolding an MVP.
Fastest responding endpoints
8 APIsMeasured lowest average latency across our own checks. Filtered for high availability and minimal rate-limiting friction.
Browse by category
58 categories, from AI and weather to open government data.
Good places to start
Verified, no key required, and simple enough to get a response first try.
Aero Key, India
Transportation
Indian Domestic Airport Data
No keyCORSHTTPS
Agent Nexus
MCP Servers
Find agent-callable APIs, MCP servers and CLIs by capability, with live health and uptime data
No keyCORSHTTPS
Agentic Engineering Jobs
Jobs
Job board for engineers building agentic systems (LangChain, LlamaIndex, CrewAI)
No keyCORSHTTPS
AI Dev Jobs
Jobs
AI/ML engineering job aggregator with REST, RSS, and MCP endpoints
No keyCORSHTTPS
AI Economics Tools
AI
Token cost, LLM energy, agent-hour and Proof-Adjusted Autonomy calculators by Michał Piszczek
No keyCORSHTTPS
AI Model Watch
AI
Daily-updated prices, context windows & deprecation/EOL dates for 190+ AI/LLM models, sourced from official provider docs
No keyCORSHTTPS
Airtel IP
Geocoding
IP Geolocation API. Collecting data from multiple sources
No keyCORSHTTPS
Free Developer Tools
Zero sign-up, client-side browser utilities for fast API debugging and conversions.
cURL converter
Paste a cURL command and get the equivalent JavaScript fetch, axios, or Python requests code.
- ✓ Methods, headers, query strings and request bodies
- ✓ JavaScript fetch, axios and Python requests
- ✓ Basic auth converted to the right header
Launch tool →
JSON formatter
Format, validate and explore JSON. Get the exact line and column when it will not parse.
- ✓ Pretty-print with your choice of indent
- ✓ Validation with the exact line and column
- ✓ Collapsible tree view for large responses
Launch tool →
CORS checker
Test whether an API can be called straight from browser JavaScript, or whether it needs a proxy.
- ✓ Runs a real cross-origin request from your browser
- ✓ Tells CORS rejection apart from the endpoint simply being down
- ✓ Reports status, timing and the headers the browser will let it read
Launch tool →
JWT decoder
Decode a JSON Web Token to read its header and claims, and see whether it has expired.
- ✓ Header and payload decoded from base64url
- ✓ exp, iat and nbf shown as dates, with expiry state
- ✓ Signature is shown but not verified — that needs the secret
Launch tool →
Engineering Guides & Tutorials
In-depth articles on fixing CORS, handling HTTP 429 rate limits, and consuming public APIs without broken builds.
fundamentals
What is an API? A plain-English guide for complete beginners
No jargon and no prior knowledge assumed. What an API actually is, why they exist, the six words you need, and a first real request you can run in your browser in under a minute.
Updated 2026-11-10Read →
howto
Build a weather dashboard with a free no-key API
A complete working dashboard in one HTML file, using no key, no build step and no backend — then the three changes that make it production-ready.
Updated 2026-11-06Read →
howto
When a free tier stops being enough
Spotting the ceiling before you hit it, the optimisations that buy another order of magnitude, and how to judge whether paying or self-hosting is cheaper.
Updated 2026-11-05Read →
howto
Surviving breaking API changes and versioning
How providers signal a breaking change before it lands, why validating at the boundary turns silent corruption into a loud error, and what to do when an API dies entirely.
Updated 2026-11-04Read →
howto
Mocking APIs during development
Intercepting requests instead of stubbing your own code, recording real responses so mocks stay honest, and the drift problem that makes mocks lie.
Updated 2026-11-03Read →
howto
Testing APIs with Postman, curl and HTTPie
Which tool to reach for when, the curl flags that actually matter for debugging, and how to turn a manual check into an automated one.
Updated 2026-11-02Read →