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PythonStudio
Python 3 in your browser

Online Python compiler
with every step visible.

Python Studio is an online Python compiler and editor at reads.fyi. Run Python 3 in your browser, supply input, and inspect execution with a step-by-step visualizer. Programs are saved on your device without an account. Python runs through Pyodide, not on the application server.

Open the Python editor Running code requires JavaScript. The guides below are readable without it.

Learning guides

01How to run Python online without installing itRun your first Python program online with Python Studio. Learn how to use the editor, read output, fix errors, and keep browser-saved files safe.Read guide 02How to use input() in an online Python compilerUse Python input() online with prepared standard input. Follow a two-line example, convert strings to numbers, and fix EOFError and ValueError.Read guide 03Visualize Python code and understand recursionUnderstand Python execution with a step-by-step visualizer. Inspect variables, recursive call-stack frames, and source lines in a small factorial example.Read guide

What the workspace does

  • Visualize execution

    Visualize records a run so you can step through each line, watch variables change, and select call-stack frames.

  • Prepared input

    Programs that call input() read one line per call from the Input tab. Output is read-only, not an interactive terminal.

  • Saved on this device

    Programs and prepared input stay in this browser's local storage. Use Download to keep a separate .py backup.

  • Local completion

    Ctrl+Space or the Suggestions button offers keywords, built-ins, and names from your program. Tab or Enter accepts.

  • Share by link

    Share puts the current code in the URL fragment. Anyone with the link can read it, so keep secrets out.

Questions learners ask

What runs Python behind the scenes?

Python Studio uses Pyodide 0.27.7, which runs CPython as WebAssembly in a browser Web Worker. Your code is not sent to the application server for execution. The first run downloads runtime files from jsDelivr.

Do I need an account or a Python installation?

No account or local Python installation is required. Open Python Studio in a compatible modern browser and run a small Python 3 console program. The initial runtime download requires an internet connection.

How do I enter input for my Python program?

Before running, open the Input tab and put each response on a separate line. Each input() reads the next line as a string. Output is read-only, not an interactive terminal. Convert numeric responses with int() or float().

Where is my code saved, and can it be lost?

Programs and prepared input are saved in this browser's local storage on this domain, not in an online account. Clearing site data or switching browsers or domains does not preserve them. Use Download to keep a separate .py backup.

Can other people see my saved programs?

Saved programs are not uploaded to the application's database. Sharing a code link makes that code readable to anyone with the link. Python code can itself make browser-permitted network requests, so do not run untrusted code containing sensitive data.

Can I install any Python package or run a web server?

This editor does not provide a general pip-install interface or automatic dependency installation. Browser and Pyodide limitations apply to packages, networking, sockets, and operating-system features. Use a local or server environment for a long-running web server.

How does the Python code visualizer work?

Visualize records a bounded run with source-line events, variable snapshots, and call-stack frames. You can step through the recording and inspect recursive callers. Recordings are limited to 500 events; large values can be abbreviated or omitted.

What does code completion support?

Completion suggests Python keywords, built-in functions, and names found in your program. Use Ctrl+Space or the Suggestions button to open it, then Tab or Enter to accept. It is local completion, not an AI assistant or a full type-aware language server.