Software Alternatives, Accelerators & Startups

Insomnia REST VS FastAPI

Compare Insomnia REST VS FastAPI and see what are their differences

Insomnia REST logo Insomnia REST

Design, debug, test, and mock APIs locally, on Git, or cloud. Build better APIs collaboratively for the most popular protocols with a dev‑friendly UI, built-in automation, and an extensible plugin ecosystem.

FastAPI logo FastAPI

FastAPI is an Open Source, modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints.
  • Insomnia REST Landing page
    Landing page //
    2023-10-05
  • FastAPI Landing page
    Landing page //
    2023-05-14

Insomnia REST features and specs

  • User-Friendly Interface
    Insomnia REST features a clean and intuitive user interface that makes it easy to create, send, and manage API requests without a steep learning curve.
  • Support for Multiple Protocols
    In addition to REST, Insomnia supports GraphQL and gRPC, making it versatile for developers working with different API protocols.
  • Environment Management
    Insomnia allows you to create and manage multiple environments, making it easier to switch between staging, development, and production settings.
  • Custom Plugins and Themes
    Insomnia supports custom plugins and themes, allowing users to extend its functionality and personalize the interface to suit their workflow.
  • Collaboration Features
    With Insomnia Teams, users can collaborate and share API requests, environments, and other resources, enhancing team productivity.
  • Cross-Platform Availability
    Insomnia is available on multiple platforms, including Windows, macOS, and Linux, providing flexibility for users on different operating systems.

Possible disadvantages of Insomnia REST

  • Resource Heavy
    Some users have reported that Insomnia can be resource-intensive, leading to potential performance issues on lower-end machines.
  • Limited Free Features
    While Insomnia offers a free tier, some of the more advanced features, such as team collaboration and sync capabilities, require a paid subscription.
  • Steeper Learning Curve for Advanced Features
    Although the basic functionalities are user-friendly, mastering the more advanced features might require a steeper learning curve.
  • Dependency on Electron
    Since Insomnia is built on Electron, it might consume more memory and disk space compared to native applications.
  • Complex Plugin System
    While the plugin system is powerful, it can be complex and challenging for users who are not familiar with JavaScript and Node.js.

FastAPI features and specs

  • High Performance
    Built on Starlette and Pydantic, FastAPI is one of the fastest frameworks for Python, providing high performance due to its asynchronous request handling.
  • Automatic Interactive API Documentation
    FastAPI automatically generates interactive API documentation via Swagger UI and ReDoc, which are very helpful for development and testing.
  • Type Checking and Validation
    With Pydantic models and Python type hints, FastAPI provides automatic data validation and type checking, reducing the chance of runtime errors.
  • Ease of Use
    Its syntax and design make it easy to learn for Python developers, offering a smooth development experience while reducing boilerplate code.
  • Asynchronous Support
    FastAPI supports asynchronous programming, allowing for better performance for I/O-bound operations, making it optimal for handling many simultaneous connections.
  • Extensive Documentation
    It has comprehensive and well-structured documentation, which is very useful for both beginners and advanced users.
  • Community and Ecosystem
    FastAPI has a growing community and ecosystem, with many plugins and integrations available to extend its functionality.

Possible disadvantages of FastAPI

  • Learning Curve for Asynchronous Programming
    Although FastAPI itself is easy to learn, grasping the concepts of asynchronous programming in Python can be challenging for beginners.
  • Complex Dependencies
    Using Pydantic for advanced validation can make the request models complex, requiring a deeper understanding of Pydantic and its functionalities.
  • Early Stage Libraries
    Some third-party libraries and extensions specifically tailored for FastAPI might still be in early stages of development and lack long-term stability.
  • Limited Real-World Examples
    Although the documentation is extensive, there might be limited real-world examples and case studies readily available compared to more mature frameworks.
  • Deployment Complexity
    Deploying FastAPI applications might be more complex in comparison to traditional synchronous frameworks, mainly due to the need for asynchronous server setups.

Analysis of Insomnia REST

Overall verdict

  • Insomnia REST is an excellent choice for developers who need a robust and intuitive tool for API development and testing. Its comprehensive features and ease of use make it a competitive option alongside other popular API clients.

Why this product is good

  • Insomnia REST is widely regarded as a powerful tool due to its user-friendly interface, extensive plugin ecosystem, and support for multiple authentication protocols. It allows users to easily build, debug, and test RESTful APIs with features like environment variables, code generation, and response validation. Moreover, its compatibility with GraphQL and gRPC makes it versatile for modern development needs.

Recommended for

  • API Developers
  • Software Testers
  • Backend Engineers
  • Technical Leads
  • Anyone involved in RESTful API development and testing

Analysis of FastAPI

Overall verdict

  • FastAPI is widely regarded as a good choice, especially for applications that require high performance, scalability, and modern Python features. It is suitable for both simple and complex projects, making it a versatile tool in the web development ecosystem.

Why this product is good

  • FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.7+ based on standard Python type hints. It is built on top of Starlette for web framework capabilities and Pydantic for data validation and settings management. FastAPI is known for its excellent performance, automatic generation of interactive API documentation (with Swagger and Redoc), and support for asynchronous programming. Developers appreciate its ease of use, detailed documentation, and helpful error messages.

Recommended for

  • Developers building RESTful APIs
  • Teams looking for a high-performance ASGI-based web framework
  • Projects that require asynchronous programming capabilities
  • Applications needing automatic generation of interactive API documentation
  • Python developers who prefer utilizing type hints for code clarity and validation

Insomnia REST videos

3 Reasons to use Insomnia REST Client in your Exploratory API Testing

More videos:

  • Tutorial - Insomnia REST Client Tutorial

FastAPI videos

FastAPI from the ground up

More videos:

  • Tutorial - 30 Days of Python - Day 14 - Web App with Flask, FastAPI, ngrok, and Invictify - Python TUTORIAL
  • Review - [PT] Python - API com FastAPI - Chat | twitch.tv/codeshow

Category Popularity

0-100% (relative to Insomnia REST and FastAPI)
API Tools
77 77%
23% 23
Developer Tools
48 48%
52% 52
Web Frameworks
0 0%
100% 100
APIs
100 100%
0% 0

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare Insomnia REST and FastAPI

Insomnia REST Reviews

Top 20 Open Source & Cloud Free Postman Alternatives (2024 Updated)
Product Introduction: Insomnia is a powerful open-source API client designed for simplicity and efficiency and works great as a postman alternative. It supports REST, GraphQL, and gRPC, making it versatile for various API types.
Source: medium.com
Best Postman Alternatives To Consider in 2025
It is a free, open-source platform that boasts a user-friendly interface and robust features like environment and collection management, code snippets, and test automation. Compared to Postman, Insomnia offers a lighter footprint and a more customizable workspace.
Postman Alternatives for API Testing and Monitoring
Insomnia is a user-friendly tool for API development and testing. Insomnia allows creating and sending HTTP and REST requests, like GET, POST, PUT, DELETE, and more. Users can view API responses, including status codes, headers, and body. This enables understanding how the application handles different response scenarios, for efficient debugging.
Top 10 HTTP Client and Web Debugging Proxy Tools (2023)
Insomnia REST is the best alternative for Postman. It has more than 350 open-source plugins, plus GraphQL built-in with multiple protocol support. Since GraphQL is an added value, you can fully automate the entire lifecycle of APIs, build and debug them efficiently and with ease.
15 Best Postman Alternatives for Automated API Testing [2022 Updated]
Insomnia by Kong enables you to deliver high-quality APIs through collaboration. This postman alternative also includes testing suites, which allow you to create functional tests and centralize APIs. With this platform’s streamlined API client, sending GraphQL, REST, and SOAP requests are simple. Defining variables such as authentication credentials allows you to manage...
Source: testsigma.com

FastAPI Reviews

The 20 Best Laravel Alternatives for Web Development
FastAPI, as the name hints, is a swift mover. Built on Starlette, it’s all about speed and performance with Python. Crafting API masterpieces at the speed of light, now that’s something.
25 Python Frameworks to Master
Since its release in 2018, it has rapidly gained popularity due to its great performance and simplicity. In fact, according to PyPi Stats, FastAPI has over 9 million monthly downloads, surpassing even full-stack frameworks like Django.
Source: kinsta.com
3 Web Frameworks to Use With Python
myapp/ is the main directory of your FastAPI application. It includes all the other files and directories needed for the application.static/ is a directory used to store static assets such as CSS, JavaScript, and image files. These assets are served directly by the web server and are typically used to add visual styling and interactivity to the application.css/, img/, js/...
Best Alternatives to FastAPI App Free for Windows (2021)
FastAPI Alternative – So many alternatives app to FastAPI that you must to know out there. And, looking for an ideal software was not easy matter. Lucky you, at this page you can find the best replacement app for FastAPI. So what you are waiting for, get the latest FastAPI alternative app for Windows 10 from this page.
Top 5 Back-End Frameworks to Consider for Web Development in 2021
FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints. It is fast when compared to other major Python frameworks like Flask and Django. FastAPI gives great flexibility to fulfill businesses’ API needs in today’s evolving world.

Social recommendations and mentions

Based on our record, FastAPI should be more popular than Insomnia REST. It has been mentiond 289 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Insomnia REST mentions (129)

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FastAPI mentions (289)

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What are some alternatives?

When comparing Insomnia REST and FastAPI, you can also consider the following products

Postman - The Collaboration Platform for API Development

Django - The Web framework for perfectionists with deadlines

Hoppscotch - Open source API development ecosystem

Flask - a microframework for Python based on Werkzeug, Jinja 2 and good intentions.

RapidAPI for Mac - Paw is a REST client for Mac.

Laravel - A PHP Framework For Web Artisans