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Free online Flask IDE
JDoodle is an online IDE that has served the programming community since 2013. You write, compile, and run code in the browser for Flask and many other languages, without installing a toolchain.
What you see on this page is JDoodle’s free Flask IDE. It is a project rather than a single file: several source files and folders, a terminal, and a browser preview beside the editor, so you can see the page your project serves and not only what it prints. Install packages fetches whatever your project's manifest lists, so you are not limited to what ships with Flask. The build JDoodle has installed is 3.0.3. You do not install Flask and you do not configure a toolchain. The environment is a machine JDoodle starts for you and keeps for the length of your session, rather than shared infrastructure, so running a project needs a JDoodle account. It is free to create, and everything on this page can be read without one. You will see this called an online Flask compiler. Flask is not compiled the way Java or C is, so the honest word is IDE: you write the project, JDoodle runs it on a server of your own and shows you the page it serves.
Online Flask IDE
JDoodle’s Flask editor on this page highlights syntax, completes as you type, matches brackets, and folds blocks. It is an online Flask IDE: you write here, then run the project in the cloud environment.
Flask versions on JDoodle
JDoodle runs Flask 3.0.3.
Frequently asked questions
Is JDoodle’s online Flask IDE free?
Yes. Running Flask on JDoodle costs nothing. It does need an account, because the environment is a machine started for you rather than shared, and an account is free to create. Paid plans add more AI credits, longer sessions and faster workspaces.
Do I need to install Flask to use JDoodle?
No. JDoodle runs Flask on its servers. Open this page in a browser and execute.
Can I run a multi-file Flask project online?
Yes. This Flask IDE already runs a project with several files, a terminal, and a browser preview.
Do I need an account to run Flask on JDoodle?
Yes, and it is free to create. Flask runs on a machine JDoodle starts for you and keeps for the length of your session, rather than on shared infrastructure, so it cannot be handed to somebody we do not know. Everything else on this page can be read without one.
Can I install packages in a Flask project?
Yes. The environment has a terminal, and Install packages fetches whatever your project's manifest lists, so a project is not limited to what ships with Flask.
Can I see the Flask app running?
Yes. The environment has a browser preview beside the editor, so you see the page your project serves rather than only its output.
Input, interactive runs, files, and the rest of the editor work the same on every language. See the JDoodle IDE documentation.
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