Fast API for Web Development: 2024 Detailed Review

The views expressed in this post are the writer's and do not necessarily reflect the views of Aloa or AloaLabs, LLC.

Choosing the right web development framework can significantly impact the efficiency of your development process and the performance of your web application. Fast API stands out by focusing on developer-friendly design, modern development practices, versatile tooling, and high-performance web solutions. Its seamless integration with async programming models streamlines development workflows, minimizing boilerplate code and potential errors.

At Aloa, we’ve worked on several web development projects, allowing us to gain extensive experience and insights into how Fast API benefited DevOps as a whole. Our team is well-versed in providing a variety of web development solutions and always stays on top of industry trends. This ensures your APIs can handle high traffic loads with ease, delivering speedy responses and enhancing the overall user experience.

Following this experience, we'll share our in-depth knowledge of the FastAPI framework. We'll go into each of its most significant strengths and weaknesses to help you weigh the pros and cons of using this framework. We'll also explore some of its diverse use cases, its expansive set of features and tools, and its compelling top five alternatives.

Let's get started!

What is Fast API?

What is FastAPI

Fast API is a Starlette-based web framework for building APIs with Python, designed to be as fast, efficient, and easy to use as possible. It leverages Python's type hinting feature, enabling developers to catch errors early during development and produce more reliable code for building high-performance web applications.

The framework also has fantastic editor support. It integrates seamlessly with tools like Swagger UI and ReDoc, allowing developers to automatically generate FastAPI documentation. This makes it valuable for complex APIs and use cases. This feature streamlines the documentation process, ensuring developers can easily maintain up-to-date and accurate API reference materials.

Use Cases for FastAPI

Use Cases for FastAPI

FastAPI’s versatility and robust features make it adaptable to a variety of use cases. With its strengths in performance, scalability, and ease of use, it is suitable for creating robust, high-performance applications. Here are some of its compelling use cases:

Build RESTful APIs

FastAPI is excellent for building RESTful APIs, also known as REST APIs. RESTful APIs are used to design networked application architecture that allows secure, quick, and efficient data exchange. The framework adheres closely to REST principles, such as statelessness and uniform interface, ensuring high performance and reliability.

Create Microservice Architectures

With its speed and asynchronous capabilities, FastAPI is a good framework for building flexible and scalable microservice architectures. Given that microservice architectures are applications split into small independent services communicating over a network, the framework’s async features let microservices handle concurrent requests even under heavy loads efficiently. 

Develop Interactive Data Dashboards

Flexibility and performance lend themselves well to developing interactive data dashboards and reporting tools. These provide users with visual insights into complex datasets that aid informed decision-making and performance monitoring. FastAPI’s async capabilities and integration with various database systems and third-party libraries allow for quick and efficient data delivery to web front-end and visualization features using JavaScript frameworks like React or VueJS.

Build Real-Time Apps

Asynchronous capabilities allow for the easy handling of real-time communication requirements. This makes it suitable for applications that need real-time and responsive data transfer, such as messaging apps, online gaming servers, and collaboration tools.

Scalability and performance makes this API framework applicable to a large variety of use cases. The framework also makes it easier to build robust HTTP endpoints for authentication and authorization, or handle complex data structures made up of multiple dictionaries.

FastAPI Tools and Features

Fast API Tools and Features

FastAPI is advantageous to use due to its range of highly efficient tools and features, which all work together to make it easier to develop and maintain APIs. Some of the most important key features include:

Pydantic Models

Pydantic, a Python library that checks whether data is formatted with specific fields and types, handles automatic data validation and serialization for this web development framework. This tool is defined by the developers in Pydantic data models, which ensures that the data sent to and received from the API follows the expected format and rules. This makes it much easier to catch errors early on during development, maintaining data integrity across the application.


Uvicorn is an ASGI server used to handle asynchronous tasks. It is favored for its high performance and low latency, which allows for the development of APIs that stay fast and responsive even under heavy traffic loads. It's also compatible with a wider range of clients due to its support for HTTP/1 and HTTP/2 protocols.

Swagger UI for Automatic Documentation

Swagger UI is primarily responsible for automatically generating interactive API documentation for the FastAPI web development framework. This feature helps developers visualize and test their APIs directly from their intended user environment, which is the web browser. This significantly streamlines the development and debugging process.

ReDoc is another option for generating API documentation with a clean and user-friendly interface. This is a great option for increasing productivity, as the documentation generated by ReDoc is aesthetically pleasing, easy to navigate, and highly functional.

Seamless Authentication and Authorization

Security and authentication measures are seamlessly integrated into each application without having to compromise databases or data models. It supports various security schemes, such as HTTP Basic and OAuth2, with JWT tokens. It also adds to Starlette's already comprehensive security features by implementing API keys through headers, cookies, query parameters, and more.

Dependency Injection

A powerful dependency injection system is one of the core strengths of FastAPI web development framework. The DI system simplifies the management of dependencies throughout the application. It also allows developers to define dependencies explicitly for automatic injection as needed, promoting cleaner source code and easier testing. 

Dependency injection and automatic data validation speed up the development process significantly. Meanwhile, seamless security integration and more accessible documentation improve the quality of code in general. Coupled with async capabilities that maximize performance, these tools result in a web framework with speed, rapid development, excellent security, and high scalability.

Pros and Cons of FastAPI

Pros and Cons of FastAPI

FastAPI's user base is growing quickly due to the number of important benefits that it bundles together in a single effective package. However, it also does have its weaknesses. Let's go into its pros and cons.

Pros of FastAPI

Certain key benefits make FastAPI the ideal web framework for a wide variety of software development projects. Compared to competitors and predecessors at the time of its release, it combined several advantages, including:

  • Performance: FastAPI is one of the fastest web frameworks available for Python developers. It is built on top of the Starlette web server, which gives it fantastic performance due to its efficient request handling and asyncio-based architecture.
  • Scalability: Another benefit of being built on Starlette is asynchronous code. Native async support enables the efficient handling of high traffic and concurrent requests, promoting both scalability and responsiveness.
  • Strong Dev Toolkit: Some features of FastAPI, including automated documentation, dependency injection, and validation streamlined development, promoting code organization, reusability, and reliability. Plus, it is designed to be used within virtual environments, ensuring consistent and isolated development and production setups.
  • Customizable Serialization: Customizable serialization options allow developers to tailor data serialization, a method for compressing complex data structures, to fit specific project requirements. This flexibility ensures efficiency in data handling and interoperability with various systems and data formats.
  • Integrated Security Features: Built-in support for common security mechanisms simplifies the implementation of authentication and authorization in applications. This makes overall security posture and compliance adherence much stronger.

Performance and scalability are immensely attractive to developers looking to build reliable web applications. These factors rely heavily on a rich toolkit that provides asynchronous support and automatic documentation.

Cons of FastAPI

Although FastAPI provides several benefits, developers may encounter some challenges and limitations. Here are the most significant ones:

  • Cluttered Main File: FastAPI tends to centralize everything in the file, which can result in crowding and maintenance issues, especially as the project gets larger. As such, your team may need to improve code organization by creating dedicated files for exception handlers and router inclusion.
  • DI Doesn't Support Singletons: Although reliable, Dependency Injection (DI) lacks native support for singleton, enabling teams to manage shared resources through singleton classes manually or making use of third-party DI libraries.
  • Syntax Learning Curve: Despite its many advantages, the framework uses a specific syntax that increases the learning curve for developers who are not familiar with asynchronous programming or standard Python type hints. It can take some time to learn the tool and enforce data models using Pydantic.
  • Unintuitive Error Handling: An occasionally confusing error-handling mechanism makes it challenging for developers to troubleshoot and debug issues. In complex applications with multiple error scenarios, this can lead to longer debugging times.
  • Limited ORM Support: Although there is support for ORMs (Object-Relational Mapping), such as SQLAlchemy and Tortoise ORM, other frameworks offer better integration with ORM to make the application and the database smoother.

Despite these limitations, FastAPI's performance, scalability, and toolkit make it a strong contender for building high-quality web APIs. It is certainly worth considering in case any issues might be a dealbreaker for a particular project.

FastAPI Reviews and Recommendations

FastAPI Reviews and Recommendations

Powered by Pydantic and Starlette, FastAPI delivers comparable performance to competing frameworks like NodeJS or Go. Although relatively new, the number of developers preferring this framework to build APIs and develop web apps is steadily growing, including some from high-profile brands.

Microsoft Senior Software Engineer Kabir Khan, for instance, integrates the framework into the core Windows product itself, as well as some Office products. Uber also uses FastAPI to seamlessly integrate machine learning models into their infrastructure, while Netflix utilizes it to create its open-source crisis management orchestration framework called Dispatch.

While the framework garners a few distinctions, there are a few instances concerning its unpolished updates and performance downgrades. One user noted a significantly lower request throughput compared to Node.js and Golang on the same machine during a benchmark test. Concerns were also raised about poor middleware performance and an almost 50% performance loss when using annotated dependencies.

FastAPI Alternatives

Although FastAPI's flexibility makes it ideal for a variety of use cases, there are alternatives to it that handle certain functions better. It is a relatively young framework, enabling competitors to have a unique edge in the industry. Let's take a look at some of this API’s biggest competitors:

1. Flask - Micro Web Framework Known for Its Simplicity


Flask is one of the predecessors to FastAPI. This micro web framework is lightweight and easy to get started with. It similarly puts emphasis on simplicity and flexibility, making it a popular choice for developers looking for a straightforward tool in building web applications. 

Notable Features of Using Flask

  • Simple Syntax: Flask is a great choice for small to medium-sized projects because of its more straightforward syntax.
  • Large Ecosystem: Being a mature framework, Flask is supported by much more extensive documentation and a larger community. 
  • Modularity: Its modular design allows developers to easily integrate third-party extensions and libraries. This makes it easier to add specific functionalities as needed without introducing bloat to the core framework.

These features have allowed Flask to enjoy an enduring longevity since its release in 2010. Its simplicity and modularity have allowed it to stay relevant up to the present day. Also, Flask’s ecosystem of extensions have further contributed to its widespread adoption among developers.

2. Django - Best for Rapid App Development


Django is a full-featured web framework intended to give developers everything they need to build any kind of web application or API. Django developers chose this framework due to its strong focus on robustness and scalability, as well as its wide range of features for building large-scale applications.

Notable Features of Using Django

  • High Level of Abstraction: This enables features like Object-Relational Mapping (ORM) facilitates seamless communication between the application and the database, accelerating development and improving integrity and security. 
  • Intuitive Admin Panel: Django’s admin panel automates routine administrative tasks. This empowers developers to effortlessly manage application data models, user authentication, and permissions.
  • Horizontal Scaling Techniques: Support for horizontal scaling techniques such as load balancing and caching mechanisms increases this framework's scalability.

Scalability lies at the core of Django’s appeal, enabled by its support for horizontal scaling techniques and efficient handling of traffic and concurrent requests. Its customization options are also attractive, allowing developers to tailor the admin interface to suit specific project requirements, further streamlining development workflows. 

3. Falcon - Best for Building High-Performance APIs Quickly


Falcon is another FastAPI web framework alternative focusing on building high-performance, fast, and efficient APIs. It is lightweight and minimalistic, particularly useful for developing RESTful services.

Notable Features of Using Falcon

  • Request and Response Flexibility: Although it doesn't automatically serialize and validate by default, its request and response flexibility gives developers more control over API endpoints. This opens up avenues for tailored optimization strategies and seamless integration with existing systems.
  • Efficient Error Handling: Falcon provides efficient mechanisms for handling errors, enabling developers to manage unexpected situations and maintain the stability of their applications. This ensures a smoother user experience and better reliability overall.
  • Lightweight Architecture: As a lightweight framework, Falcon boasts minimal overhead. Its streamlined design prioritizes efficiency and speed, making it well-suited for building high-performance APIs with fast response times even under heavy loads. 

Falcon's design flexibility emphasizes simplicity and performance. This equates to reduced overhead and improved responsiveness in API handling. It also facilitates rapid development and integration with other services, making it an ideal choice for scalable applications.

Key Takeaway

Fast API offers a robust combination of performance, ease of use, and scalability that shows a marked improvement over its predecessors. Its important selling points include highly streamlined development process and performance optimization. Together with its intuitive design, wide range of features and tools, and an ever-growing community, it makes it suitable for developers of all skill levels looking to build robust applications.

When considering this web framework for your next project, it’s important to understand how it fits within the larger landscape of web development frameworks. Compare its features, ecosystem, and performance benchmarks with other options to gain a comprehensive understanding of its advantages and drawbacks, ensuring you make a well-informed decision.

Need help in building out a web application using Fast API? Reach out to our Account Executives at [email protected] for tailored web solutions. At Aloa, we’re happy to give you a detailed overview of our processes, from connecting you to the best-fit talent to deploying your product and development roadmap in 2024 and beyond!

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