This online Python compiler runs Python 3.12 (Pyodide 0.26.1) directly in your browser tab. Pyodide is the CPython interpreter compiled to WebAssembly, so your script executes on your own device inside a Web Worker instead of on a remote server, which makes the page a Python sandbox you can use with no setup. Use this Python online editor for quick experiments, coursework, interview practice or checking a snippet from a tutorial: type your code, press Run Code and read the output in the terminal panel. There is no account to create and nothing to install.
Uses only the standard library, so it runs immediately. Counter.most_common returns the most frequent items first.
from collections import Counter
text = """the quick brown fox jumps over the lazy dog
the dog barks and the fox runs"""
counts = Counter(text.split())
for word, n in counts.most_common(3):
print(f"{word:>6}: {n}")
Pyodide packages are downloaded on first use. Load the package with pyodide_js.loadPackage, then import it as usual. The first run takes a few seconds while the package downloads.
import pyodide_js
await pyodide_js.loadPackage("numpy")
import numpy as np
matrix = np.arange(1, 10).reshape(3, 3)
print(matrix)
print("Column sums:", matrix.sum(axis=0))
print("Mean:", matrix.mean())
The sandbox supports top-level await, so you can await coroutines directly. asyncio.gather runs both tasks concurrently, so the total wait is about 0.5 seconds rather than 0.8.
import asyncio
from dataclasses import dataclass
@dataclass
class Job:
name: str
seconds: float
async def run(job: Job) -> str:
await asyncio.sleep(job.seconds)
return f"{job.name} finished after {job.seconds}s"
jobs = [Job("download", 0.5), Job("resize", 0.3)]
for line in await asyncio.gather(*(run(j) for j in jobs)):
print(line)
Yes, it is free and needs no account. When you press Run Code, your script executes inside your own browser in a Web Worker, using Pyodide, which is CPython compiled to WebAssembly. The code is not uploaded; it only leaves your device if you create a Share link and send it to someone.
It runs Python 3.12 (Pyodide 0.26.1). Pyodide 0.26.1 bundles CPython 3.12, so features such as match statements, nested quotes inside f-strings and the typing syntax added in 3.12 work. Run import sys followed by print(sys.version) to see the exact build string the interpreter reports.
Both, in a sense. CPython first compiles your source code into bytecode, the internal representation of a Python program, and its virtual machine then executes that bytecode. Pyodide is CPython compiled to WebAssembly, so the same two steps happen here inside your browser. That is why a syntax error anywhere in the script is reported before any of it runs.
Usually you do not need to: the interpreter compiles a script to bytecode automatically when it runs. To do it explicitly, python -m py_compile or python -m compileall writes .pyc bytecode files, and tools such as PyInstaller bundle a script with an interpreter into an executable. In this online Python compiler there is no separate step; press Run Code.
Yes, but they are not pre-loaded. First run import pyodide_js and await pyodide_js.loadPackage("numpy"), replacing numpy with the package you need, then import it. Pure-Python wheels from PyPI can be installed with micropip once micropip itself is loaded the same way. Packages with native code work only if Pyodide provides a WebAssembly build.
Your code runs in a background Web Worker that has no interactive terminal, so it cannot pause and wait for keyboard input. Replace input() calls with fixed values or a list of test inputs while you experiment, then restore them when you run the script in a local Python installation.
Yes. It suits algorithm and data structure practice, working through tutorials and checking small scripts, because the standard library is available and output appears straight away. It does not replace a local setup when you need files that persist, network sockets, GUI toolkits or packages without a WebAssembly build.
Click Share in the toolbar. The sandbox compresses your code into a link and copies it to your clipboard. Anyone who opens the link sees the same code in the editor and can run it in their own browser. Nothing is stored on a WebFiddle server, so very long scripts produce long URLs.
Paste this iframe into any web page and readers can run code without leaving it. The snippet travels in the URL, so there is nothing to host and no account to create. Open the sandbox, write your example, press Share, then append that link’s query string to the embed URL to preload it.
<iframe src="https://webfiddle.xyz/embed/python" width="100%" height="480" loading="lazy"
style="border:1px solid #ddd;border-radius:8px"
title="WebFiddle python sandbox"></iframe>