Sure, you can definitely use Flask as a backend-only server. Just skip over any sections in the documentation and tutorials having to do with Jinja and templates. You won't be needing them. FastAPI would be another option for a Python backend. Answer from nonself on reddit.com
Ffnext
ffnext.io › blog › python-backend-with-flask-for-beginners
Python Backend with Flask for Beginners
May 23, 2022 - After creating a new python file (app.py) and downloading the required flask dependency (pip install flask), by writing a few lines of code, you can immediately start a web service running on localhost with the following command: python app.py.
Reddit
reddit.com › r/flask › is flask the tool i want for a basic backend server?
r/flask on Reddit: Is Flask the tool I want for a basic backend server?
March 15, 2023 -
I'm building a very simple React frontend and want to build my backend server in Python.
After reading what Flask is in 4 different places I'm still a bit confused. It's generally described as "a web application framework written in Python."
Is a web application framework designed to return the content that appears on a web page, whereas that would normally live in React (or whatever other FE framework)?
If I only want to spin up a reliable web server with some basic endpoints to be hit by my React web application, is Flask the right tool for me? Or should I go with something else?
Top answer 1 of 6
17
Sure, you can definitely use Flask as a backend-only server. Just skip over any sections in the documentation and tutorials having to do with Jinja and templates. You won't be needing them. FastAPI would be another option for a Python backend.
2 of 6
7
I like Flask for what you are describing. Depending on what you need - the way to scale it is to put it behind gunicorn and give a few workers per CPU
Sure, you can definitely use Flask as a backend-only server. Just skip over any sections in the documentation and tutorials having to do with Jinja and templates. You won't be needing them. FastAPI would be another option for a Python backend. Answer from nonself on reddit.com
Videos
Full Flask Course For Python - From Basics To Deployment
How to Create a Web Application in Python using Flask - YouTube
11:33
Flask Backend Setup | Flask and Python Backend #1 - YouTube
How to Create a Flask + Next.js Project | Python Backend + ...
09:10
How to Bundle a React Frontend with a Flask Backend for Deployment ...
Flask
flask.palletsprojects.com
Welcome to Flask — Flask Documentation (3.1.x)
Configuring from Python Files · Configuring from Data Files · Configuring from Environment Variables · Configuration Best Practices · Development / Production · Instance Folders · Signals · Core Signals · Subscribing to Signals · Creating Signals · Sending Signals · Signals and Flask’s Request Context ·
Full Stack Python
fullstackpython.com › flask.html
Flask - Full Stack Python
Visualize your trip with Flask ... as the backend web framework. Microservices with Flask, Docker, and React teaches how to spin up a reproducible Flask development environment with Docker. It shows how to deploy it to an Amazon EC2 instance then scale the services on Amazon EC2 Container Service (ECS). Build a Video Chat Application with Python, JavaScript ...
GeeksforGeeks
geeksforgeeks.org › python › flask-tutorial
Flask Tutorial - GeeksforGeeks
1 week ago - Routing: Maps URLs to Python functions using simple decorators. Flexible Database Choice: No built-in ORM, allowing use of tools like SQLAlchemy or raw SQL. API Development: Well-suited for building RESTful APIs and backend services. Development Server: Includes a built-in server for local testing during development. This section introduces Flask, compares it with Django and shows how to install it on Windows to start building web applications.
MetaCTO
metacto.com › home › blog › development › what is flask? a comprehensive guide to the python backend framework
What Is Flask? A Guide to the Python Backend Framework | MetaCTO
July 6, 2025 - Flask is a backend framework written in Python. It is designed to make getting started quick and easy, with the ability to scale up to complex applications. The framework provides developers with a solid foundation built on sensible defaults, ...
freeCodeCamp
freecodecamp.org › news › how-to-use-python-and-flask-to-build-a-web-app-an-in-depth-tutorial-437dbfe9f1c6
How to use Python and Flask to build a web app — an in-depth tutorial
December 19, 2017 - Overall, flask-base provides a great starting point for making your flask application. Of course the backend may be fairly verbose to code, but as a result, it gives you very granular control over your app.
GitConnected
levelup.gitconnected.com › flask-a-flexible-micro-framework-for-backend-dev-in-python-9cfaf1114095
Flask: A Flexible Micro-Framework for Backend Dev in Python | by Griffin Poole | Level Up Coding
July 1, 2020 - So instead, I decided to use a backend framework written in Python to make the most out of a toolkit better suited for the job I had in mind. ... Flask is a micro framework for web development in the Python language.
Educative
educative.io › blog › python-flask-tutorial
Python Flask tutorial: Build your first Flask application!
Flask is a micro-framework developed in Python that provides only the essential components - things like routing, request handling, sessions, and so on. It provides you with libraries, tools, and modules to develop web applications like a blog, wiki, or even a commercial website.
Hyperskill
hyperskill.org › courses › 29-python-backend-developer-with-flask
Python Backend Developer with Flask
Master Python backend using Django for your career goals. Build, deploy, and optimize scalable web apps with skills in API, database management, and security. ... Discover the power of Flask, a Python framework for web development.
Top answer 1 of 3
3
You're creating a new application in your test module - meaning that you have no registered endpoints.
You'll need to import the app created in your server module.
from your_package.server import app
and use that as you're currently doing.
Ideally your server.py and your app.py are separate - meaning you have app.py with your app configuration and server.py imports the app required, and tests import the app required, so on and so forth.
Example:
application.py
import sys
import json
from flask import Flask, request, render_template
app = Flask(__name__)
from mf import gameplay
game = gameplay.Game()
@app.route('/')
def index():
return render_template('mainmap.html')
@app.route('/api', methods=['POST'])
def api():
data_json = request.data.decode()
data = json.loads(data_json)
return game(data_json)
server.py
from application import app
app.run('0.0.0.0', 5000, threaded=True)
test.py
from application import app
def test_1():
"""Example test"""
with app.test_client() as client:
response = client.get('/')
print(response)
That should work!
2 of 3
0
Firstly ensure your Flask application is running and simply you can use tools like postman or cUrl to test your endpoint.
Quora
quora.com › Is-Flask-backend-or-frontend
Is Flask backend or frontend? - Quora
Answer (1 of 3): In web development, ... somewhere, not in the browser, and that makes it “back end”. Flask, which is written in Python, is back end....
Swovo
swovo.com › blog › what-is-flask-overview-of-the-flask-python-framework-2024
What is Flask? Overview of the Flask Python Framework in 2026
If your goal is to create a simple ... a built-in development server and speedy debugging functions. Flask is a good choice for backend work in mobile applications....
DigitalOcean
digitalocean.com › community › tutorials › how-to-make-a-web-application-using-flask-in-python-3
How To Build a Web Application Using Flask in Python 3 | DigitalOcean
2 weeks ago - Learn how to build a Flask web application from the ground up using Python, covering routes, templates, forms, and deployment.
Top answer 1 of 2
5
If you are using same machine, you do not need to use flask-cors.
Update:
As you are using Docker you can use flask-cors to handle CORS.
I found that the AJAX calls were not correct in your JS code. const url = "localhost:5000/test"; does not provide information on request protocol.
I followed these steps to run Flask application successfully using Docker and accessing the /test endpoint using JS outside Docker.
- I updated AJAX request
- Added
Dockerfileto run Flask application inside Docker - Build and run the
Dockerfile - Get the IP address of running Docker container.
- Used the IP address in AJAX call in JS code which is outside Docker.
Folder structure:
.
├── backend.py
├── Dockerfile
├── readme.md
└── requirements.txt
requirements.txt:
Flask==1.0.2
Flask-Cors==3.0.7
Dockerfile:
FROM python:3
ENV PYTHONBUFFERED 1
RUN mkdir /code
WORKDIR /code
ADD requirements.txt /code/
RUN pip install -r requirements.txt
ADD . /code/
CMD ["python", "backend.py" ]
Build Docker file:
docker build -t flask-docker .
Run Docker:
docker run -p 5000:5000 flask-docker
* Serving Flask app "backend" (lazy loading)
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
Get Docker container ID:
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
69cb7d5d243a flask-docker "python backend.py" 15 minutes ago Up 15 minutes 0.0.0.0:5000->5000/tcp
Get Docker container IP address:
docker inspect --format '{{ .NetworkSettings.IPAddress }}' 69cb7d5d243a
172.17.0.2
Use this IP address in AJAX request in HTML file:
<html>
<head>
<title>Frontend</title>
</head>
<body>
<div id="data"></div>
<button type="button" id="btn">Grab data</button>
<script type="text/javascript">
document.getElementById("btn").addEventListener('click', add);
function add()
{
const api_url = "http://172.17.0.2:5000/test";
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("data").append(this.responseText);
}
};
xhttp.open("GET", api_url, true);
xhttp.send();
}
</script>
</body>
</html>
backend.py:
from flask import Flask, request, jsonify
from flask_cors import CORS
app = Flask(__name__)
CORS(app)
@app.route("/test")
def test():
return "It's working"
if __name__ == "__main__":
app.run(host='0.0.0.0', port=5000)
Output:
2 of 2
1
Add the following line below app = Flask(__name__):
CORS(app)
Check out flask-cors simple usage
Medium
medium.com › @kanaecoder › creating-a-full-stack-website-with-react-frontend-and-python-flask-backend-91ec2cbd81e0
Creating a Full Stack Website with React Frontend and Python Flask Backend | by Kanaecoder | Medium
September 22, 2023 - First, we begin by setting up the backend using Flask. Create a new directory for your project and within it, create a new Python file for your Flask application. For instance, you can name it app.py.
Auth0
auth0.com › home › blog › developing restful apis with python and flask
Developing RESTful APIs with Python and Flask | Auth0
November 18, 2025 - Build RESTful APIs using Python and Flask. This post covers everything from setting up your Flask application and managing dependencies to creating API endpoints and deploying with Docker
DataCamp
datacamp.com › tutorial › python-backend-development
Python Backend Development: A Complete Guide for Beginners | DataCamp
August 18, 2024 - Python is used mainly for backend development. It is known for its simplicity, readability, and a robust ecosystem of frameworks like Django and Flask, designed for server-side logic, database management, and API development. However, Python can also be used in some frontend tasks, such as ...
GitHub
github.com › taptorestart › python-backend-examples
GitHub - taptorestart/python-backend-examples: Flask, FastAPI, Django, DRF
Flask, FastAPI, Django, DRF. Contribute to taptorestart/python-backend-examples development by creating an account on GitHub.
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Forked by 13 users
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