Development APIs remove busywork from software teams: code execution sandboxes, screenshot services, proxy rotation, webhook testing, and CI helpers. Most are freemium with generous developer tiers, but watch for CORS restrictions — many are designed for backend use only. Health status matters more here than in most categories, since broken dev tools tend to stay broken.
| API | Pricing | Auth | CORS | Health | |
|---|---|---|---|---|---|
| IPinfo Another simple IP Address API | Freemium | No | Yes | Profile | |
| Image-Charts Generate charts, QR codes and graph images | Freemium | No | No | Profile | |
| Insomnia A free API client that allows you to design, debug, test, and mock APIs locally, on Git, or cloud. | Free | OAuth | Yes | Profile | |
| JSON 2 JSONP Convert JSON to JSONP (on-the-fly) for easy cross-domain data requests using client-side JavaScript | Free | No | No | Profile | |
| JSONsilo.com Host JSON files and instantly convert them into REST API endpoints. Free tier available. No backend required. | Freemium | API Key | No | Profile | |
| Kroki Generate diagrams from textual descriptions. Supports Mermaid, PlantUML, Graphviz, Ditaa, and 20+ other diagram languages. Free, no auth required. | Free | No | No | Profile | |
| Kubernetes API Kubernetes API public API. | Unknown | Unknown | Yes | Profile | |
| LaunchDarkly REST API Build custom integrations with the LaunchDarkly REST API | Free | Unknown | Yes | Profile | |
| MAC address vendor lookup [DEAD - extended outage] Look up vendor and device details for any MAC address or OUI. Identify manufacturer, country, and block range information. WARNING: Domain returns HTTP 521 (Web Server Is Down) - 17 consecutive failures. | Freemium | API Key | No | Profile | |
| MY IP Get your public IP address and basic IP information. Simple, free, no authentication required. | Free | No | No | Profile | |
| Make API API for Make scenarios, connections, organizations, teams, and automation resources. | Freemium | API Key | Yes | Profile | |
| Microcks API v1.7 API API offered by Microcks, the Kuebrnetes native tools for API and microservices mocking and testing (microcks.io) | Unknown | API Key | Yes | Profile | |
| MySQL Visual EXPLAIN Transform MySQL EXPLAIN output into interactive visual graphs. Analyze query execution plans to identify bottlenecks and optimize database performance. | Free | No | Yes | Profile | |
| Nationalize.io Predict the likely nationality of a first name using statistical analysis. Returns country probability scores. Free, no auth required. | Free | No | Yes | Profile | |
| Netlify REST API for managing Netlify sites, deploys, DNS, forms, and serverless functions. Automate static site deployments and manage web infrastructure. | Freemium | OAuth | No | Profile | |
| NetworkCalc Network calculation API for subnet math, DNS lookups, binary conversions, and network security tools. Free, no auth required. | Free | No | Yes | Profile | |
| Nhost API Backend platform APIs for auth, GraphQL, storage, functions, and project resources. | Freemium | API Key | Yes | Profile | |
| OSDB REST API v1 API An OpenAPI description of the OpenLink Smart Data Bot REST API v1 | Free | Unknown | Yes | Profile | |
| Open Page Rank API for retrieving PageRank data and domain authority metrics for websites. Compare SEO metrics across domains using the Open PageRank algorithm. | Freemium | API Key | No | Profile | |
| OpenAPI Generator Online API This is an online openapi generator server. You can find out more at https://github.com/OpenAPITools/openapi-generator. | Free | Unknown | Yes | Profile | |
| Piloterr Web scraping API with headless browser management, automatic proxy rotation, and structured JSON data extraction from any website. | Freemium | API Key | No | Profile | |
| PipeDream Integration platform and workflow automation API. Connect APIs, build event-driven workflows, and run custom code on Pipedream's serverless infrastructure. | Freemium | OAuth | No | Profile | |
| Pipedream REST API REST API for Pipedream workflows, sources, components, accounts, and event-driven automation. | Freemium | API Key | Yes | Profile | |
| Postman Postman API for managing collections, environments, monitors, and automating API testing workflows. Access Postman's collaboration and CI/CD features programmatically. | Freemium | API Key | No | Profile | |
| Proxmox VE API REST API for managing Proxmox Virtual Environment (PVE) - open-source server virtualization management. Control VMs, containers, storage, and networking. | Freemium | API Key | No | Profile | |
| ProxyCrawl Web scraping and crawling API with built-in anti-CAPTCHA, headless browser, and proxy rotation. Handles JavaScript rendering and structured data extraction. | Freemium | API Key | No | Profile | |
| ProxyKingdom Rotating residential proxy API delivering a fresh working proxy on every request. Built for web scraping and data collection. | Freemium | API Key | No | Profile | |
| QR code Generate and decode / read QR code graphics | Freemium | No | No | Profile | |
| QR code Generator Static and Dynamic QR code generator with custom and unique QR code design | Freemium | API Key | Yes | Profile | |
| Qrcode Monkey Integrate custom and unique looking QR codes into your system or workflow | Freemium | No | No | Profile | |
| QuickChart Generate chart and graph images | Freemium | No | No | Profile | |
| RSS to JSON Returns RSS feed in JSON format using feed URL | Free | No | No | Profile | |
| Remote Settings PROD API Remote Settings PROD API public API. | Free | Unknown | Yes | Profile | |
| Request Baskets API RESTful API of [Request Baskets](https://rbaskets.in) service. Request Baskets is an open source project of a service to collect HTTP requests and inspect them via RESTful API or web UI. Check out the [project page](http | Unknown | API Key | Yes | Profile | |
| Ritc API Rules in the Cloud | Unknown | Unknown | Yes | Profile | |
| Runscope API Manage Runscope programmatically. | Free | Unknown | Yes | Profile | |
| SEO Tags Generator API The Generate SEO Tags API generates all the most important META tags based on any content | Freemium | API Key | No | Profile | |
| Sandbox API Sandbox API | Free | Unknown | Yes | Profile | |
| ScrapeNinja Scraping API with Chrome fingerprint and residential proxies | Freemium | API Key | No | Profile | |
| Scrapfly Scrapfly is an enterprise-grade solution providing Web Scraping API that aims to simplify the scraping process by managing everything: real browser rendering, rotating proxies, and fingerprints (TLS, HTTP, browser) to bypass all major anti-bots. | Freemium | API Key | No | Profile | |
| ScrapingAnt Headless Chrome scraping with a simple API | Freemium | API Key | No | Profile | |
| ScrapingDog Proxy API for Web scraping | Freemium | API Key | No | Profile | |
| ScreenshotAPI.net Create pixel-perfect website screenshots | Freemium | API Key | Yes | Profile | |
| ScreenshotOne.com Convert URLs, HTML, or Markdown into PNG, JPEG, WebP, or PDF with a simple screenshot API | Freemium | API Key | Yes | Profile | |
| Screenshotbase Screenshot API, 1000 free requests per month | Freemium | API Key | No | Profile | |
| Scrnify Screenshot and video capture API to transform any URL into high-quality images and recordings | Freemium | API Key | No | Profile | |
| Serialif Color Color conversion, complementary, grayscale and contrasted text | Free | No | No | Profile | |
| Shadify Service for generating data and executing logic to create various games and puzzles | Free | No | No | Profile | |
| SheerSEO API Sheerseo API has 2 stages:<br>First stage - initiating the task: You fill in your task and receive in return the task id. <br>Second stage - collecting the results: send a request containing the task ids you got at the f | Unknown | Unknown | Yes | Profile | |
| Sonar Project Sonar DNS Enumeration API | Free | No | No | Profile | |
| SonarQube SonarQube REST APIs to detect bugs, code smells & security vulnerabilities | Freemium | OAuth | No | Profile | |
| StackExchange Q&A forum for developers | Free | OAuth | Yes | Profile | |
| Statically A free CDN for developers | Freemium | No | Yes | Profile | |
| Stoplight API Stoplight API public API. | Free | Unknown | Yes | Profile | |
| Supadata Scrape YouTube, web, and files into text. Get AI-ready, clean data for your next project. | Freemium | API Key | No | Profile | |
| Swagger Generator API This is an online swagger codegen server. You can find out more at https://github.com/swagger-api/swagger-codegen or on [irc.freenode.net, #swagger](http://swagger.io/irc/). | Paid | Unknown | Yes | Profile | |
| Swagger2OpenAPI Converter API Converter and validator for Swagger 2.0 to OpenAPI 3.0.x definitions | Unknown | API Key | Yes | Profile | |
| The Jira Cloud platform REST API Jira Cloud platform REST API documentation | Unknown | Unknown | Yes | Profile | |
| TinyUID.com API Paste a Long URL link to shorten it | Unknown | Unknown | Yes | Profile | |
| Tolgee Open-source localization and internationalization platform with API for managing translations, in-context editing, and automated localization workflows. | Freemium | API Key | No | Profile | |
| Tyk Open-source API gateway and management platform with rate limiting, authentication, analytics, and service mesh capabilities. | Freemium | API Key | No | Profile | |
| Upstash QStash API HTTP message queue, scheduling, and fanout API for serverless applications. | Freemium | API Key | Yes | Profile | |
| UserAgent User agent string parser API that identifies browser, device, OS, and bot detection from UA headers for analytics and personalization. | Free | API Key | No | Profile | |
| Userstack API Secure User-Agent String Lookup JSON API | Free | Unknown | Unknown | Profile | |
| VSOnline API Public APIs for managing VS Codespaces | Free | Unknown | Yes | Profile | |
| Vercel API Vercel REST API for managing projects, deployments, domains, environment variables, and teams on the Vercel frontend cloud. | Freemium | API Key | No | Profile | |
| Wandbox Online code compiler API supporting 35+ programming languages including C++, Python, Ruby, and more. Free to use. | Free | No | No | Profile | |
| Web Scraping API ApyHub web scraping API for extracting structured data from any public URL with content parsing and formatting options. | Freemium | API Key | No | Profile | |
| WebScraping.AI Web scraping API with built-in residential proxies, JavaScript rendering, and structured data extraction. | Freemium | API Key | No | Profile | |
| Who Hosts This API Discover the hosting provider for any web site | Paid | API Key | Yes | Profile | |
| WireMock API WireMock API public API. | Free | Unknown | Yes | Profile | |
| YADG API that scrapes music release data from major platforms and renders results using customizable templates for artists and labels. | Free | API Key | Unknown | Profile | |
| YAMLine Convert YAML to JSON on-the-fly with a simple REST API. No authentication required. | Free | No | No | Profile | |
| ZEIT API ZEIT API public API. | Paid | Unknown | Yes | Profile | |
| Zapier Platform API Platform API for building, managing, and testing Zapier app integrations. | Freemium | API Key | Yes | Profile | |
| Zuplo API management platform for building, deploying, and documenting APIs with built-in auth, rate limiting, and monetization. | Freemium | API Key | Yes | Profile | |
| elmah.io API This is the public REST API for elmah.io. All of the integrations communicates with elmah.io through this API.<br/><br/>For additional help getting started with the API, visit the following help articles:<br/><ul><li>[Us | Free | Unknown | Yes | Profile | |
| httpbin.org API A simple HTTP Request & Response Service.<br/> <br/> <b>Run locally: </b> <code>$ docker run -p 80:80 kennethreitz/httpbin</code> | Free | Unknown | Yes | Profile | |
| import.io Retrieve structured data from a website or RSS feed | Freemium | API Key | Yes | Profile | |
| ipfind.io Geographic location of an IP address or any domain name along with some other useful information | Freemium | API Key | No | Profile | |
| jsDelivr Package info and download stats on jsDelivr CDN | Free | No | No | Profile | |
| n8n Public API Public API for n8n workflows, credentials, executions, tags, users, and projects. | Freemium | API Key | Yes | Profile | |
| scraperBox Undetectable web scraping API | Freemium | API Key | No | Profile | |
| watchful.li API watchful.li API public API. | Free | Unknown | Yes | Profile |
Start with pricing and auth: free tiers and no-auth APIs are fastest to prototype with. Then check CORS if your app calls the API from the browser, and health before you commit — a great development API that's been down for a week will block your launch. Each profile below shows all of these signals plus rate limits where documented.