The 123 best APIs & Dev Tools

Chrome extension for testing and previewing a website on more than 80 phone, tablet and desktop screens.

Overlay browser that floats any website on top of whatever app you are in.

Generate text, images and video from the command line.

Preview any URL or localhost on 123 real phone, tablet, laptop and monitor sizes.

Stateful API emulation so integrations can be tested in CI.

Reduce your image size without compromising on quality. Experience the best JPEG and image compression tool online.

Scraping API that returns structured data instead of raw HTML.

Framework-agnostic toolkit for building drag and drop interfaces.

Free open-source desktop app that handles the shipping steps freelancers repeat.

Google's open source tool for auditing web performance, accessibility, SEO and best practices.

Microsoft's free tools for finding and fixing accessibility issues in web, Windows and Android apps.

Open-source browser API for running and controlling cloud browsers at scale.

See the tech stack behind any website, from CMS to analytics.

Mac and iOS app that makes App Store Connect faster for updates, localization and releases.

Browser automation CLI built for AI agents, with debugging built in.

Form endpoint that collects submissions without writing a backend.

End-to-end testing that writes and maintains the tests with AI.

TypeScript SDK for transactional email across providers, one clean API.

Open-source framework for connecting AI agents across messaging platforms.

Directory pairing popular paid software with its open-source alternatives.

API for adding, verifying and monitoring customer domains.

Terminal UI core written in Zig with TypeScript bindings for building CLIs.

Open-source starter kit and UI library for building AI design apps.

One API across several sandbox providers for running untrusted code.

Swaps localhost port numbers for stable .localhost URLs during development.

AI QA testing across web and mobile, run before each release.

Template for selling paid macOS apps with payments, licence keys and auto-updates already done.

The browser for ambitious web developers and designers.

Where the world builds software, code, review and ship.

The complete DevOps platform in a single application.

The connectivity cloud, security, performance and edge compute.

Complete user management and authentication for modern apps.

The API platform for building and using APIs.

APIs for SMS, voice, video and authentication.

The email API for developers, built on React Email.

Application monitoring and error tracking for developers.

The fast and reliable search and discovery API platform.

The world's largest API hub to find and connect to APIs.

An open-source, lightweight API development ecosystem.

Beautiful, AI-native documentation that converts users.

The fast way to build internal tools and business apps.

The open-source product analytics suite for engineers.

Add a shopping cart to any website with a few lines of code.

Payments infrastructure and financial APIs for the internet.

The open-source metering and usage-based billing platform.

Monetization for developers, payments, subscriptions and more.

The industry-standard tool to build and document UI components.

AI-powered code reviews right inside your pull requests.