Flask and Django are both Python frameworks that are used to build web applications with interfaces based mainly on HTTP, REST, and GraphQL protocols. Django is much bigger than Flask, but both have a wide fan base and rich documentation. Together they account for most of the market share of Python-based web applications. For this reason, the two frameworks are very often compared to each other. What are the differences and which is better suited to your needs?
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Django standard and secure off-the-shelf solutions
Django is a high-level full stack web framework that offers a standard method for rapid development. It is great for writing large and complex web applications, as its primary goal is creating complex database-driven websites. Users appreciate it for its consistency and completeness that enables the quick and easy creation of majestic monolith products, giving developers all the necessary tools and allowing them to code less on their own. It will work great for projects that require the involvement of the whole team, where several developers need to work on the product simultaneously. Django is very convenient for planning and execution if you have a clear vision of the final shape of the application. However, using the pre-defined code blocks of Django doesn't allow for too much flexibility as such monolithic apps lack modularity.
As a conclusion, Django is friendly to fast development of tightly-coupled applications that should be redeveloped altogether if needed. So, if you’re looking for a framework that will allow you to do minor code changes without affecting the full image, you better go with something different.
Flask flexibility and control in a minimalist package
Flask, on the other hand, presents a completely different approach. It is a micro framework characterized by simplicity and minimalism and equipped with only basic tools. Flask is also not dependable on external libraries, so it’s ideal for creating microservices and simple projects, manageable by one person. Its biggest advantage is its enormous flexibility and large scope for customisation, making it possible to build everything from scratch. Flask users can easily change approaches and solutions, and the original assumptions do not tie their hands if the concept changes. On the other hand, this approach can be more demanding, because with Flask you have to code everything yourself and combine everything that the external libraries offer - all by yourself. For many developers, this full control can be a problem because it requires more attention and doing each step yourself. However, it gives you a great opportunity to work out the whole product (and Python itself) from the inside, because working in Flask you're involved in the process of creating each stage step by step.
When choosing Django, be aware of some limitations
Even though Django is seemingly limited in its solutions, you still can use either raw SQL or its ORM to get the needed range of customization in terms of writing queries.
The actual problem with Django’s lack of flexibility is that it can actually bring about another serious issue which lies in the general customization. What it means is that as long as you stick to Django's "way of doing things", many of them will work out-of-the-box. However, if you want to even slightly alter the development process from Django’s standards, you’ll end up putting A LOT of effort into it. And we mean it.
The second issue with this framework is that optimization of the app made on Django still requires being meticulous. Just blindly relying on the basic Django classes and ORM can lead to horrific issues with the code performance in the future.
Flask also requires compromises
Flask won't work well for large, complex projects that multiple developers need to work on. It is a minimalist framework created for simple products and microservices. For small projects, its flexibility, transparency and control over all stages are very convenient, but it doesn't work when you need to meet complex business requirements. This framework is good when you need to create something quickly to demonstrate how an application works, but complex, long-term projects built on Flask are too much of a risk.
Flask also requires the use of external libraries and third-party add-ons, making it less secure than monolithic Django. The risks associated with using global objects and the resulting bugs are sometimes so large that even experienced developers can't handle them.
Flask vs. Django
At this stage, you already understand the general characteristics of the two Python frameworks. It's time for you to find out how they differ. Let's see how they compare in specific aspects of working with them.
Both frameworks are designed to create a functioning application as quickly as possible. Django allows you to quickly create large, complex web apps. It's a through and through, "batteries-included" type of web framework, containing everything you might need to get started quickly. Applications developed in Django can be worked on by an entire team at once, with all the necessary tools at their disposal, allowing you to release an MVP in record time. And, it's easier to do major changes with Django. You heard us.
Flask, on the other hand, is ideal for simple applications. It allows you to create the first version of a microservice very quickly and present its functioning. It is ideal for quick drafts of the products, which can be extended in the future. In applications created with its help, you will find only what you put in the code, without any additional features. Flask is also easy to learn by one programmer, so when you do not have a whole team at your disposal, and you want to quickly show a simple implementation, it will be a good solution. Even though Flask seems to be overall more flexible than Django, you should know the direction of the final product with the first one, as any major changes will require more low-level work.
Ease of learning and use
The answer to this question is not so obvious, because it depends on what we mean by the term "learn". If in a short time you want to get a full, ready to use application - Django will be easier, or at least more convenient. However, this framework relieves us in many activities that for most programmers are simply tedious, for example, authorization, configuration or security. Django is also equipped with all the necessary tools, so it guides us through the entire process, tossing ready-made solutions.
However, in this situation, there is a risk that working in Django we will get a finished application, but we will not understand the mechanisms behind it and what happened in our product. If we want to understand the development process inside out, Django will not teach us that. Learning the exact mechanics of Django is therefore much easier for developers who already know Python and accept the stepper learning curve of that framework.
Flask, in terms of the operation itself, is easier to learn because it is just simpler and smaller than Django. It allows you to quickly and independently create the simple application you need. Moreover, every working functionality depends on the code you write, so you have transparency and understanding of everything that happens in your application. But the simplicity of the framework does not mean that working with it requires fewer skills. On the contrary - great flexibility, using external libraries, combining them and coding on your own means that you need a lot of awareness and discipline to work in Flask.
Both frameworks offer us a low entry threshold, but it takes years to explore all their secrets.
Handing over a project
Everyone in the industry knows how critical it is to hand over a project to a new team or company, so it's good to make this process as painless as possible. In this aspect, Django definitely wins: applications in this framework are not only easier to hand over during the process, but are also more convenient to scale after the application is ready. This is also where the dark side of Flask's flexibility manifests itself, as it will be harder for a new person to take up the thread and custom creative process of a previous developer. In Django, this problem doesn't exist because the assumptions we want to achieve are known from the very beginning, and working in a closed, monolithic system is much more consistent and universal, so it's easier for a new team to take up the broken process and develop the finished product.
Flexibility and control
If you want full control over the applied solutions, Flask is much better. This is a nice framework for experienced, creative developers who like to reach for non-standard ideas and do not want to be limited by an imposed style of work. In this framework, you can implement everything exactly the way you want. Simplicity and minimalism, and at the same time the lack of restrictions make flexibility the greatest strength of Flask.
Although Flask offers virtually the same security features as Django, using third-party add-ons and external libraries poses much more risk. Each tool developed and shared by other teams means great possibilities, but also the risk of errors. If you care primarily about functional security, a consistent Django system will be a better choice.
Django is a bigger and older framework with a larger community. As such, it will be much easier to find relevant support, jobs and developers working with it. Django is much more likely to be used by large companies for typical web applications. Flask is a younger and smaller framework, but still the second largest of the Python community, and its fan base continues to grow. More independent companies with a focus on custom solutions and simpler applications may be more interested in building with Flask.
When to use
- For an application secured from common vulnerabilities, like CSRF, SQL Injection, XSS, Clickjacking;
- Complex, large, demanding applications;
- Less experienced team that needs ORM support;
- Default, secure configurations, typical web applications.
- Small, rather simple applications where performance is key;
- Possibility to grasp the whole system by oneself;
- Lightweight and modular solutions that are easy to deploy;
- Situations where you want to have full control over every aspect of the process.
So, Flask or Django?
There is no definitive answer to which system is better, as both systems give huge possibilities of the open-source system at your disposal. The choice solely depends on your needs and variables such as project complexity, team structure, working style and priorities.
Django is a secure, popular, consistent system that provides you with everything you need to get started and deliver a product quickly. Django has all the tools in one place, takes the hassle out of many things, and is suitable for larger teams, even less experienced ones. Its downsides are its limitations - this framework will be too cramped for more creative, experienced developers who like unusual solutions. Django won't help you understand how many elements of your application work, because it will simply do them for you - it's convenient, but it doesn't give you the full insight.
Flask will be perfect when you need to quickly introduce a micro change in a web application, or if you like combining, and designing everything from scratch and have full control over the entire process. Unfortunately, Flask cannot handle large, complex applications, and external components are associated with considerable risk. And in regards to non-hobby projects, we also recommend not to reinvent the wheel with Flask, but go with the proven solutions.
When choosing a framework to work with, take into account your own needs and the specifics of your work and choose the best solution for you.