10 Best API Tools Tools in 2026

The OpenAI API provides programmatic access to GPT-4, GPT-3.5, DALL-E, Whisper, and other models that have redefined what's possible with AI. If you're building products that use AI for text generation, code completion, image creation, or speech recognition, this is where most teams start. GPT-4 is the flagship text model. It handles complex reasoning, follows nuanced instructions, and produces coherent long-form content. The context window extends to 128k tokens, meaning you can include substantial documents or conversation history. For many applications, GPT-4 is simply the most capable option available. The chat completions API is the primary interface. You send a conversation—a sequence of messages with roles—and receive a response. System prompts establish behavior, function calling enables tool use, and streaming returns partial responses in real-time for better UX. Embeddings power semantic search and similarity. Convert text to vectors, store in a vector database, and find relevant content without keyword matching. This enables RAG (retrieval-augmented generation), where GPT answers questions based on your specific data. Fine-tuning lets you customize models on your data. While GPT-4 isn't fine-tunable, GPT-3.5 can be trained to match your style, terminology, or specific task requirements. The fine-tuning API handles the training; you provide examples. Pricing is usage-based on tokens processed. GPT-4 costs significantly more than GPT-3.5, so many applications use GPT-3.5 for simple tasks and escalate to GPT-4 when needed. For high-volume applications, understanding costs is important. The developer experience is excellent. SDKs exist for every major language, documentation is comprehensive, and the playground helps prototype prompts before coding.

Git tracks changes to code and enables collaboration through branches, merges, and distributed development. The version control system that won—now assumed in any serious development workflow. The model is powerful once understood. The ecosystem is vast. The tool is essential. Developers don't choose Git—it's the version control standard that everything else builds on.

OpenAI is an AI research company that builds some of the most advanced AI systems in the world. Creator of GPT-4, ChatGPT, DALL-E, and Whisper. Access their models through APIs for text generation, image creation, speech recognition, and more. OpenAI leads in large language models and continues pushing the boundaries of artificial intelligence. The company that brought AI into the mainstream with ChatGPT.

Stripe is a financial infrastructure platform for internet businesses. Accept payments from anyone, anywhere. Billing handles subscriptions and invoicing. Connect powers marketplace payments. Treasury provides banking as a service. The payments infrastructure that powers millions of businesses from startups to Fortune 500 companies.

Prettier formats code automatically, removing debates about style. It makes decisions about formatting—line length, quotes, semicolons, indentation—so you don't have to. The opinions are opinionated, but consistency is the point. The key insight is that formatting should be automated, not discussed. Prettier makes choices, and teams accept them. Energy goes to the code, not the style guide. Multi-language support covers JavaScript, TypeScript, CSS, HTML, JSON, YAML, and more. One tool handles formatting across your project. Editor integration formats on save. Write code however you want; Prettier fixes it when you save. The workflow eliminates thinking about formatting entirely. CI integration catches unformatted code. Fail builds that haven't been formatted, ensuring consistency in the repository. The configuration is intentionally limited. You can adjust a few options, but Prettier doesn't offer fine-grained control. This limitation is a feature—it prevents style debates. For teams adopting Prettier, the transition period involves adjusting to its choices. After that, formatting simply isn't a concern anymore.

OpenAI Platform provides API access to GPT-4, DALL-E, and other advanced AI models. It enables developers to integrate natural language processing, image generation, and other AI capabilities into their applications. Used by thousands of companies to build AI-powered products.

Cloudflare DNS resolves domain names faster than most alternatives, and it's completely free. Update records through a clean interface, enable DNSSEC with a click, and benefit from Cloudflare's global network. The API enables automation. DNS analytics show query patterns. Records propagate quickly globally. Anyone managing DNS who wants speed, reliability, and a modern interface uses Cloudflare DNS for free DNS that outperforms paid alternatives.

Apify is a web scraping and automation platform that enables developers to build, run, and scale data extraction workflows. The platform provides a marketplace of pre-built scrapers (called Actors) and tools to create custom automation solutions for any website. The platform operates on a hybrid subscription plus usage model where plans include monthly platform credits consumed by compute units, data storage, and proxy usage. Actors handle everything from simple data extraction to complex browser automation, with support for JavaScript rendering and anti-bot bypass. Apify provides datacenter and residential proxy networks for reliable scraping at scale. Results can be stored in datasets and exported to various formats or integrated via API. The platform includes scheduling, monitoring, and webhook integrations for production workflows.

Zapier is an AI orchestration platform that automates workflows between 7,000+ apps with Zaps, Tables, Forms, and Zapier MCP for connecting data, automating tasks, and building custom integrations without code.

pytest tests Python with elegant simplicity. Testing that feels natural to write—the framework Python developers prefer. The syntax is clean. The fixtures are powerful. The plugins extend infinitely. Python developers use pytest because it makes testing pleasant.