What is it?
Run Python lets you write and run real Python 3.12 (Pyodide) on any device, even a phone or a locked-down school computer, with nothing to install. The code runs in a background worker inside your browser, so endless loops can be stopped, input() reads from the Input box, and packages such as NumPy and pandas load automatically when you import them.
Who is it for?
Students doing Python homework or practicals, teachers demonstrating code in class, and beginners who cannot install Python on their computer.
How to use it
- Type or paste your program into Python code. Ctrl + Enter runs it; Tab indents with 4 spaces.
- If the program uses input(), type one answer per line in Input (for input()).
- Press ▶ Run. The first run shows “Starting Python (about 10 MB the first time, then it is cached)…”.
- Read the Output. Use Copy output, Download .py or Clear output. Press ■ Stop if it never finishes.
Worked example
name = input("Your name: ")
marks = [78, 85, 91]
print(f"{name}, average: {sum(marks)/len(marks):.1f}")
Type Asha in the Input box and press Run. The output is “Your name: Asha, average: 84.7”. Your code is saved on this device, so it is still there next time; it is never uploaded.
Errors and how to fix them
- “The program ended with an error (see the output)”: the error message from the language is in the Output box. Read its last line first: it names the problem and the line number.
- EOFError: input() ran out of answers. Add one more line to the Input box for every input() call.
- “Stopped. Python will restart on the next run”: you pressed Stop; variables from before are gone.
- ModuleNotFoundError: only the standard library and Pyodide’s packages are available; network sockets and files on your computer cannot be used.
- Nothing happens, or a “Could not load” message: the first use downloads the library. Check your internet connection, turn off an ad or script blocker for this site, and reload the page.
Open the tool: Run Python
Still stuck?
Contact support. Tell us which tool or page you were using, what you tapped, what you saw, and your phone or computer and browser (for example: Android phone, Chrome). We reply by email.
Questions, or an error not listed here?
Tell us in the comments: what you were doing, the exact message you saw, and your device and browser. We read every comment and add new fixes to this article.