Best Free API Design Software of 2026

Xano offers a fully-managed, scaleable infrastructure that powers your backend. You can also quickly create the business logic that powers your backend with Xano without writing a single line or use one our pre-made templates to launch quickly and without compromising security or scale. You can quickly create custom API endpoints with just one line of code. Our out-of-the box CRUD operations, Marketplace extensions and templates will accelerate your time to market. Your API is "ready-to use" so you can connect to any frontend immediately and concentrate on your business logic. Swagger automatically documents everything so that you can connect to any frontend easily. Xano uses PostgreSQL, which offers the flexibility of a relational and the Big data needs that a NoSQL solution. You can add features to your backend with just a few clicks. Or, you can use pre-made templates and extensions to jumpstart the project.

Tyk is an Open Source API Gateway and Management Platform that is leading in Open Source API Gateways and Management. It features an API gateway, analytics portal, dashboard, and a developer portal. Supporting REST, GraphQL, TCP and gRPC protocols We facilitate billions of transactions for thousands of innovative organisations. Tyk can be installed on-premises (Self-managed), Hybrid or fully SaaS.

With industry-leading IBM API Connect, you can expertly secure and manage all aspects of your API ecosystem across multiple cloud platforms. This includes boosting socialization efforts and monetization efforts. IBM API Connect®, a complete, intuitive, and scalable API platform, allows you to create, securely expose and manage APIs across multiple clouds. This allows you and your customers to power digital applications and encourage innovation. IBM API Connect can also be used with other capabilities as an IBM Cloud Pak®, which can help you reach your application modernization goals in your journey to the cloud. IBM API Connect security is built using the advanced IBM(r] DataPower(r] Gateway. It comes with a single, signed and encrypted gateway that greatly reduces the risk of cybersecurity incidents. IBM API Connect has 22% market share, more than any competitor1.1 It's a trusted API solution that manages and protects services and data across multiple cloud environments.

Directus is an Open Data Platform that allows you to manage any SQL database's content. It offers a powerful API layer to developers and an intuitive app for non-technical users. Directus is written entirely in JavaScript (primarily Node.js or Vue.js), and it is modular and extensible. This allows it to be tailored to your specific project needs. Our platform can be used to manage digital experiences as a headless CMS, a database client for democratizing information, or as a standalone web app for back-office CRM, inventory, business intelligence and project management.

SyncTree strives to be a "Super Connecting Platform" that can easily connect any services you want. With SyncTree, which consists of SyncTree STUDIO, a solution for building backend business logic with block coding, and Block Store, a platform for buying and selling pre-made backend function blocks like App Store, you can organically utilize data and connect services to achieve unlimited service expansion.

Treblle is a federated API Intelligence platform that unifies API visibility, governance, and security in a single enterprise-grade solution. Designed for complex environments, Treblle connects seamlessly through one integration and supports deployment on-prem or in private cloud—meeting even the strictest regulatory and data residency requirements. Once integrated, Treblle instantly maps your entire API landscape with automatic discovery, generating real-time inventories and eliminating shadow APIs. Its observability tools track every request and response, surfacing performance issues, anomalies, and SLA breaches across all services. Advanced analytics give teams insights into traffic, latency, endpoint usage, and client behavior, making debugging, optimization, and scaling easier and 15 times faster. Security is built-in, not bolted on. Treblle provides runtime protection, threat detection, schema validation, and governance policies to safeguard APIs across environments. It empowers DevOps and platform teams to implement shift-left strategies and enforce consistent practices across the lifecycle. With its AI-powered Integration Assistant, Treblle simplifies onboarding and improves developer workflows. Whether you’re running internal microservices or customer-facing APIs, Treblle gives you the clarity and control to move faster, reduce risk, and scale with confidence.

Specmatic offers a no-code, specification-driven, and visual approach to API testing by leveraging API specifications to automatically execute positive and negative tests. Specmatic Studio offers broad format and protocol support across REST, SOAP, GraphQL, gRPC, WebSockets, and asynchronous messaging systems (message queues and event-driven APIs). Specmatic Studio utilizes specifications as the single source of truth for contract testing, service virtualization (mocking), workflow testing and resiliency testing. It enables backward compatibility testing which detects breaking changes to APIs at design time and in CI, helping teams prevent consumer-impacting regressions before deployment. Specmatic Genie uses API requirements to assist with API design and enables interactive validation of the API specification prior to generating an MCP server. Specmatic MCP Auto-Test generates test cases for JSON validation and tool calls. Specmatic focuses on functional correctness, contract compliance, resiliency, and compatibility testing. It offers open-source testing tools for OpenAPI, MCP and SOAP. Postman collections can be imported to aid specification creation and test generation.

DreamFactory is a REST API Management Platform. Auto Generate REST APIs. A cloud-based or on-premise API generation platform that is enterprise-grade. Instantly generate database APIs to build faster applications. The biggest bottleneck in modern IT is eliminated. Your project can be launched in weeks instead of months. DreamFactory creates a secure, standardized and reusable, fully documented, live REST API. DreamFactory can integrate any SQL or NoSQL file storage system or SOAP service. It instantly creates a RESTAPI with Swagger documentation, user role, and more. Every API endpoint is secured with User Management, Role Based Access Controls, SSO Authentication and Swagger documentation. Rapidly create mobile, web and IoT apps using REST-based APIs. DreamFactory offers example apps for iOS, Android and Titanium.

Stoplight is an API Design, Development, & Documentation platform. Stoplight Platform enables consistency, reuseability, quality, and ease in your API lifecycle. Here's what Stoplight Platform can do for you: Stoplight Studio's visual designer makes it easy to design APIs Stoplight Prism mocking allows you to automatically create mock API designs - Invite external and internal users to give feedback and collaborate on your designs - Create faster and more powerful APIs - Use Stoplight Spectral to test and enforce style guidelines To create a pleasant experience, document both internal and externe APIs automatically To quickly scale up API programs that are well-governed, standardized, and collaborative, you can use and integrate design-first workflows.

SwaggerHub is a comprehensive platform that integrates API design and documentation, specifically crafted for teams to maintain uniformity and discipline throughout the API development process. Enhance your team's design efficiency while preserving quality and consistent organizational style through a robust Editor that adheres to the latest Swagger (OpenAPI) specifications. This powerful Editor features intelligent error feedback and automatic syntax completion to streamline the coding process. Additionally, it includes Style Validators to maintain design uniformity across various APIs. With API Mocking, teams can simulate operations without the need for actual code. The Domains feature allows for the storage, reuse, and referencing of common OAS syntax across multiple APIs, promoting efficiency. Centralizing your API design and development in one location enables seamless collaboration among team members on new projects and easy discovery of existing APIs. Manage the entire API lifecycle through a single, centralized internal repository hosted in the cloud, which enhances accessibility and coordination among team members. By utilizing SwaggerHub, teams can significantly improve their workflow and foster innovation in API development.

Amazon API Gateway is an entirely managed service designed to simplify the process for developers to create, publish, maintain, monitor, and secure APIs, regardless of scale. Serving as the "entrance" for applications, APIs facilitate access to data, business logic, or services from the backend. Through API Gateway, developers can build both RESTful and WebSocket APIs, which are essential for enabling real-time two-way communication in applications. This service supports both containerized and serverless environments as well as web applications. It efficiently manages the complexities of processing hundreds of thousands of simultaneous API requests, handling traffic management, CORS, authorization and access control, throttling, monitoring, and versioning. Moreover, there are no upfront fees or minimum charges associated with API Gateway; instead, you only pay for the API calls and data transfer you utilize. With a tiered pricing structure, as your API usage grows, you can benefit from reduced costs, making it a cost-effective solution for businesses of all sizes. Additionally, the simplicity and scalability of API Gateway allow developers to focus more on building features rather than managing infrastructure.

Create modular APIs with a zero-trust approach and deploy them serverlessly, regardless of the legacy systems in place. Constructing a robust infrastructure can be quite challenging, as even the most proficient teams may find it difficult to adhere to architectural plans amidst rapidly changing requirements and the complexities of the technology landscape. Typegraphs serve as programmable virtual graphs that represent all the elements of your system architecture. They allow for the composition of APIs, storage solutions, and business logic in a manner that ensures type safety. Typegate acts as a distributed HTTP/GraphQL query engine that compiles, optimizes, executes, and caches queries on typegraphs, while also handling authentication, authorization, and security measures for you. You can easily integrate third-party dependencies and begin reusing existing components with ease. The Meta CLI enhances your workflow by providing live reloading features and facilitating one-command deployment to Metacloud or any personal instance. Furthermore, Metatype addresses a critical gap in the technology ecosystem by offering a novel method for building rapid, developer-centric APIs that meet growing demands. By utilizing these innovative tools, you can streamline your development process and adapt more swiftly to the changing tech environment.

Illustrate sample API requests and their corresponding responses while articulating the logic of API endpoints in plain language. Conduct tests on your API endpoints and adjust your prompt, response format, and request format as needed. With a simple click, deploy your API endpoints and seamlessly integrate them into your applications. Create and launch intricate application functionalities without needing to write any code, all within a minute. No need for individual LLM accounts; just register for Backengine and begin your development process. Your endpoints operate on our high-performance backend architecture, accessible instantly. All endpoints are designed to be secure and safeguarded, ensuring that only you and your applications can access them. Effortlessly manage your team members so that everyone can collaboratively work on your Backengine endpoints. Enhance your Backengine endpoints by incorporating persistent data, making it a comprehensive backend alternative. Additionally, you can utilize external APIs within your endpoints without the hassle of manual integration. This approach not only simplifies the development process but also enhances overall productivity.

Experience seamless navigation through a tidy and organized interface, enabling you to concentrate on the essential aspects of effectively testing and collaborating on APIs. Firecamp provides a user-centric design alongside a variety of robust features, facilitating an efficient API development process and improving teamwork among members. You can dynamically set variable values for use throughout the platform, ensuring consistency and ease of access. Additionally, create visually appealing API documentation to share with both your team and the wider community. Execute API Collection Tests directly in the terminal or integrate them into your CI/CD pipeline, while also testing and troubleshooting your authentication endpoints with support for multiple authentication methods. This comprehensive approach not only boosts productivity but also fosters a collaborative environment for API development.

Testfully offers an extensive array of features, ranging from robust API client capabilities to sophisticated testing and monitoring functionalities. Users can take advantage of versatile cloud and offline storage options, facilitate effortless collaboration among teams, and enjoy straightforward migration, all within a single, comprehensive multi-platform tool. The platform simplifies the transition of data from Postman or Insomnia, allowing for seamless integration into Testfully. With a focus on flexibility and security, users can establish global, environment, and folder variables tailored to either the workspace or individual users. The tool also allows for the customization of authentication methods, parameters, headers, and body content, making it easy to create any HTTP request. Collaboration is made simple as you can invite team members, assign specific roles, and manage folder permissions effectively. Testfully supports major authorization schemes such as OAuth2, ensuring secure and efficient access management. Whether you are dealing with straightforward tasks or more intricate scenarios, Testfully streamlines the testing process without requiring any coding skills, thus making advanced API testing more approachable and user-friendly. Users can execute requests within a folder either simultaneously, sequentially, or in a random order with a single click, enhancing efficiency. Additionally, it allows for response validation and contract testing through a declarative format, further eliminating the need for coding and simplifying the overall testing experience. Overall, Testfully is designed to cater to both novice and experienced users, ensuring that everyone can leverage its capabilities effectively.

Experience stunning API documentation that is cherished by both teams and users alike. Finally, you can create API documentation that your entire team can take pride in. In mere seconds, you can publish visually appealing API reference documents and customize them in just a few minutes. Instantly satisfy developers with essential features such as three-panel layouts, an interactive try-it console, automatically generated code snippets, SEO optimization, and an intuitive search function. Everyone knows that outdated documentation and scope creep can lead to frustration. Keep your API documentation up-to-date by integrating your preferred source control with our cloud-based workflows. Our platform is compatible with a wide range of options, including on-premise solutions and various API management systems. Set up a comprehensive developer portal within minutes by leveraging your API definitions as valuable assets. Enhance the experience with tutorials, quick-start guides, and developer tools, all while enjoying extensive customization options. Ensure your API definitions are validated, linted, and bundled seamlessly, allowing for the creation of consistently on-spec OpenAPI documents. Connect your API reference and tailor every detail to impress your API consumers, ultimately fostering a more engaging and productive environment for developers. With these capabilities, your documentation will not only serve its purpose but also become a pivotal resource for ongoing collaboration.

Sparrow provides a comprehensive toolkit designed to enhance the entire API lifecycle, guiding research and development teams towards achieving excellence in design-first API development. With cURL, users can easily send API requests while supporting essential methods such as GET and POST. This platform simplifies API interactions by efficiently managing headers, data, and authentication. As a collaborative open-source solution for API development, Sparrow streamlines the creation of outstanding APIs. Through collaborative efforts, developers are able to advance their practices earlier in the development timeline, resulting in more robust APIs and expedited delivery. Users can enjoy seamless parallel testing across various environments, allowing them to gather valuable insights in real-time. Furthermore, Sparrow equips users with powerful tools to secure and manage their API data, along with the option for self-hosting, granting full control over their testing environments. Additionally, users can remain informed about the latest updates, insights, and resources provided by Sparrow to further enhance their development experience. This commitment to continuous improvement ensures that developers are always equipped with the best practices and innovations in API development.

APIGen is an innovative AI-powered platform that allows users to swiftly design, construct, test, and launch custom APIs within minutes. By simply providing a straightforward or intricate prompt, APIGen automatically creates all the required routes, schemas, and internal functionalities, with options for adjustments as necessary. This platform utilizes a dedicated language model tailored specifically for API development, which guarantees efficient and versatile code generation. Users can seamlessly integrate their databases, connect to various third-party APIs, and take advantage of features such as code export, real-time modifications, and instant deployment to APIGen's cloud infrastructure. Additionally, APIGen takes care of authentication, session management, and security protocols for each API, offering enterprise-level protection with over 50 branches of custom tests and automatic error detection. The platform includes essential functionalities for user administration, token creation, data encryption, and generates comprehensive documentation automatically for every facet of the API. By streamlining these processes, APIGen not only enhances productivity but also simplifies the complexities often associated with API development.

Flowcode merges the ease of visual programming with the robust capabilities of traditional coding, enabling users to create rapidly while managing the underlying infrastructure. This allows developers to concentrate on tackling complex logical challenges. With its intuitive drag-and-drop interface, users can utilize powerful logic-based nodes, making it simpler to visually trace API calls for quicker bug detection. The platform facilitates effortless version management, rollbacks, and updates, providing a seamless user experience. Moreover, it enables the integration and orchestration of various AI models to craft tailored AI APIs. Built on Flyde, an open-source visual programming language, Flowcode operates within VS Code and seamlessly integrates with existing TypeScript code, web browsers, and Node.js environments. Users can efficiently address straightforward tasks through visual flows while also delving into intricate logic with custom code nodes. Additionally, it offers the flexibility to export data and APIs for deployment on personal servers, ensuring independence and adaptability. Managing database operations is made easier with abstracted PostgreSQL connections, while users also have the option to link to other databases for more specialized requirements, fostering a versatile programming environment. The combination of these features empowers users to innovate and streamline their workflows effectively.

Hoppscotch simplifies the process of creating and testing APIs, enabling quicker product launches. Build APIs with speed, conduct instant tests, and automatically document and share your work. From initial prototypes to final production, you can develop efficiently without the hassle of switching between different tabs. Everything necessary for seamless API development is provided by Hoppscotch. Set up dedicated workspaces for your teams, controlling access as needed. Collaborate with your colleagues in real-time, ensuring smooth teamwork. You can even deploy Hoppscotch on your own servers for added flexibility. Organize your requests into collections or folders to facilitate sharing with your team. Manage your environment variables for consistent usage across your projects. Additionally, keep track of your request history for easy reference. Modify headers, authenticate your requests, generate random data, and explore many more features at your disposal. Test your APIs thoroughly and write assertions to verify responses. Hoppscotch supports over 30 languages, allowing you to use it in your preferred tongue. Keep an eye on all activities within your workspace, tracking who performed actions and when. Utilize your existing SSO provider for easy login to Hoppscotch, and efficiently manage your users, workspaces, and other resources. Furthermore, the intuitive interface ensures that both novices and experienced developers can navigate the platform effortlessly.

NoCodeBackend is an intuitive, AI-driven platform designed for the swift creation of production-ready APIs without the need for coding. With a simple interface, users can easily set up databases, tables, and columns, while the platform automatically generates the necessary API endpoints. By utilizing AI-assisted prompts, NoCodeBackend enables users to articulate their API requirements effectively, allowing the system to manage the development seamlessly. Furthermore, the platform provides automated documentation through Swagger, ensuring that the API documentation is both clear and comprehensive, which enhances the overall experience for developers. This innovative approach not only saves time but also empowers users to focus on building their applications without technical barriers.

Create-API.dev is an innovative tool powered by AI, developed by Kong, that enables users to swiftly create high-quality OpenAPI specifications through an intuitive chat interface. By simply communicating your intended endpoints or a rough concept, the service utilizes a sophisticated Google LLM to produce comprehensive, standards-compliant OpenAPI definitions that are ready for sharing, testing, and deployment. This web-based application is lightweight and requires no installation, allowing for easy access from anywhere. The outputted specifications can be seamlessly exported in standard YAML or JSON formats, facilitating integration with existing API gateways and documentation processes. Furthermore, Create-API.dev adheres to Google’s Generative AI Prohibited Use Policy, emphasizing the importance of exercising caution before using or publishing any content generated by AI, highlighting the necessity for human oversight in the final implementation. Users can confidently leverage this tool while remaining mindful of the guidelines to ensure optimal results.

WunderGraph Hub serves as a comprehensive platform that empowers development teams to collaboratively design, manage, and enhance APIs within a well-defined workflow. Acting as a unifying layer for API development, it facilitates cooperation among teams working on distributed services, enabling them to design schemas, suggest modifications, and agree on API functionalities prior to the start of implementation. The platform features a visual design canvas that allows developers, API owners, and consumers to outline capabilities, model schema architectures, and engage in discussions about requirements in a collaborative environment. After a design is established, Hub automatically creates schema proposals and collects feedback from stakeholders through controlled workflows, guaranteeing that any proposed changes to the API undergo thorough review, approval, and documentation before deployment. This method fosters a transition from casual communication and disjointed documentation to a more organized collaboration process that emphasizes clear and traceable decision-making. Ultimately, WunderGraph Hub enhances the efficiency of API development by ensuring that all team members are aligned and informed throughout the project lifecycle.

You can eliminate the need to develop back-end code. Connect to your database easily using the server address or connection string. You can customize your API methods by selecting the data you want to read, update, delete, or modify. It's done! Your front-end development team can now access your API. No back-end required. PrestoAPI supports SQL Server, MySQL and PostgreSQL. You can assign roles to users in the application or to specific projects. PrestoAPI is protected by Identity Server, OAuth 2.0 and Active Directory.

Mockoon provides a wide array of features that simplify the process of API mocking significantly. By downloading the latest version of Mockoon, you can begin crafting mock APIs immediately! You have the flexibility to create an unlimited number of mock APIs, each with countless routes, and can run them simultaneously. Additionally, the command-line interface (CLI) enables you to execute your mock APIs in various automated environments, such as servers, CI/CD pipelines, and GitHub Actions. The tool supports importing and exporting mock APIs in the Swagger/OpenAPI format, streamlining integration with other platforms. You can configure your mock APIs to deliver multiple responses based on specific rules or randomly, complete with any headers, body content, or HTTP status codes you choose. Furthermore, Mockoon allows you to serve your mock API over a secure TLS connection using a self-signed certificate. You can customize your routes by adding specific response headers and enjoy features like auto-completion for ease of use. The application also lets you introduce latency at both the environment and route levels, or even combine both settings for more nuanced testing. To assist with troubleshooting, all incoming requests and outgoing responses are meticulously logged, making debugging much simpler. In addition, Mockoon's proxy mode can redirect any undefined routes to a designated host, ensuring that your mock environment remains functional. Finally, it also includes file serving capabilities, complete with automatic MIME type detection and support for templating, enhancing the versatility of your mock API setup.