Best Free API Tools Tools in 2026

ElevenLabs provides the most realistic AI voice technology for content creators and developers. Generate lifelike speech from text in 29 languages. Clone voices with just minutes of audio samples. Real-time voice synthesis for conversational AI applications. API for developers building voice-enabled products. AI voices indistinguishable from human speech.

Apollo Studio provides visibility into your GraphQL APIs. See which queries clients actually run, track performance by field and resolver, and catch schema changes that would break existing clients. The explorer lets developers browse and test queries against your schema interactively. Schema checks in CI prevent breaking changes from reaching production. Contract testing validates that client queries match server capabilities. Teams running GraphQL in production need observability. Apollo Studio provides the monitoring and governance that keep GraphQL APIs healthy as they evolve.

Dropbox Sign (formerly HelloSign) is an electronic signature platform integrated with Dropbox. Send documents for signature with a simple, intuitive experience. Templates streamline recurring signature workflows. API enables embedding signatures in your applications. Legally binding and compliant with major regulations. E-signatures that feel native to the Dropbox experience.

HelloSign (now Dropbox Sign) is electronic signature software for getting documents signed online. Simple interface makes signing easy for recipients. Templates save time on frequently-used documents. API enables embedding signatures in your applications. Audit trails provide legally-binding proof. Integrations with Dropbox, Google Drive, and business tools. E-signatures made simple for businesses of all sizes.

Postman is an API development platform used by over 30 million developers and 500,000 organizations worldwide. It provides a unified workspace for designing, testing, documenting, and monitoring APIs across HTTP, GraphQL, gRPC, WebSocket, and MQTT protocols. Teams can collaborate through shared workspaces, collections, and mock servers while maintaining version control via native Git integration. The platform includes an AI-powered agent mode for automating repetitive API tasks, an API catalog for internal service discovery, and a CLI for CI/CD pipeline integration. Postman supports the full API lifecycle from spec design through production monitoring, making it the industry standard for API-first development workflows.

The Azure MCP Server implements the Microsoft Copilot Protocol (MCP) specification, enabling AI agents to connect seamlessly with over 40 different Azure services. It acts as a central hub that provides Azure context to AI agents, enhancing their capabilities and allowing them to interact with Azure resources more effectively. This server can be deployed standalone or integrated with various Integrated Development Environments (IDEs) and other MCP clients. Designed for developers and AI engineers, the Azure MCP Server simplifies the process of building intelligent applications that leverage Azure's extensive cloud services. It streamlines authentication, provides access to a wide range of Azure functionalities, and supports both sovereign cloud environments and local development setups. The server aims to accelerate AI development on Azure by providing a unified interface for agent-to-service communication.

Albato is an AI-driven integration platform that connects 1,000+ applications through a no-code visual builder. It supports two-way data synchronization, webhook triggers, scheduled automations, and bulk data migration between business tools. With built-in AI capabilities for ChatGPT, Gemini, and Claude, teams can add intelligent data transformation directly into workflows. Albato positions itself as a cost-effective Zapier alternative at roughly 60% lower pricing, serving 200,000+ users from small businesses to enterprises with a white-label embedded integration option.

Quetzly is a comprehensive tool designed for developers and IT professionals working with geospatial APIs. It provides a unified platform to test, monitor, and visualize various geospatial services, including WMS, WFS, ArcGIS, and GeoJSON endpoints. Users can send requests (GET, POST, PUT, PATCH, DELETE), tweak parameters, and inspect JSON responses with an integrated editor. The platform also offers robust monitoring capabilities, allowing users to track service health and status over time with configurable intervals and a clear history of checks. A key feature is its ability to visualize geospatial data directly on a map, supporting WMS, WFS, and ArcGIS services, with options to toggle layers and export data as GeoJSON or Shapefile. Quetzly aims to bridge the gap between GIS expertise and modern developer workflows, speeding up geospatial development, reducing downtime, and delivering high-quality location services. It is currently in beta, with plans for enterprise-grade monitoring features like multi-level health checks, data quality validation, performance monitoring, and real-time alerting. Quetzly is ideal for anyone needing to validate responses, inspect geometry, verify properties, set up automated checks, and preview spatial data on an interactive map. It helps organize related endpoints into sets for efficient workflows and is free for both personal and commercial use.

Shippo provides shipping API and discounts. Multi-carrier shipping for e-commerce-labels and tracking with rate shopping. The carrier options are many. The rates are discounted. The API is straightforward. E-commerce shipping through APIs often uses Shippo for multi-carrier access.

Integrately is a workflow automation platform connecting 1,500+ applications with over 20 million pre-built automation templates. It enables users to set up integrations between business tools like CRMs, email marketing platforms, project management apps, and payment processors without coding. The platform offers a visual workflow builder with branching logic, webhooks, auto-retry, and multi-step automations. Integrately positions itself as a simpler, more affordable alternative to Zapier, with a free plan offering 100 tasks/month and paid plans starting at $19.99/month for 2,000 tasks.

Amazon API Gateway is a fully managed AWS service for creating, publishing, maintaining, monitoring, and securing APIs at any scale. It supports REST APIs, HTTP APIs, and WebSocket APIs, handling hundreds of thousands of concurrent API calls with built-in traffic management, authorization, throttling, and monitoring. HTTP APIs offer up to 71% cost savings over REST APIs for serverless workloads, while WebSocket APIs enable real-time bidirectional communication for chat and streaming applications.

Hygraph (formerly GraphCMS) is a headless CMS that pioneered GraphQL-first content APIs. The platform focuses on content federation - connecting and unifying content from multiple sources. Hygraph is known for its powerful GraphQL API, content localization, and flexible content modeling. The platform is popular among teams building complex content architectures that need to combine content from different systems into a unified API.

Algolia is a search and discovery API platform offering instant search, AI-powered recommendations, personalization, and analytics for websites and applications.

Swell provides headless commerce for developers. E-commerce API with flexibility-developer-first commerce infrastructure. The flexibility is high. The developer experience is prioritized. The headless is native. Developers building custom commerce choose Swell for flexible e-commerce API.

Veryfi provides AI-powered OCR APIs and SDKs designed for document capture, data extraction, and fraud detection. It enables businesses to automate the processing of various documents like invoices, receipts, checks, and identity cards, transforming unstructured data into structured, actionable information. The platform leverages pre-trained multimodal models to deliver high accuracy and speed, eliminating manual data entry and streamlining workflows. Veryfi is ideal for developers and businesses across various industries, including FinTech, CPG, Backoffice Automation, Construction, Healthcare, and Real Estate. It allows them to build next-generation applications that automate expense tracking, bill payments, loyalty programs, supply chain management, KYC, and more. With features like mobile SDKs, no-code workflow automation, and enterprise-grade security, Veryfi helps users ship AI-powered features faster and improve operational efficiency.