Convert Python to JavaScript Free — Instant, No Signup
Paste your Python code and get the JavaScript equivalent in seconds. Handles syntax differences automatically — free and unlimited.
Free forever · no signup · no credit card · unlimited
import os
# Folder to clean up — change this to your path
FOLDER = "./photos"
for i, name in enumerate(sorted(os.listdir(FOLDER)), start=1):
src = os.path.join(FOLDER, name)
if not os.path.isfile(src):
continue
ext = os.path.splitext(name)[1].lower()
dst = os.path.join(FOLDER, f"photo_{i:03d}{ext}")
os.rename(src, dst)
print(f"{name} -> {os.path.basename(dst)}")This script renames every file in a folder to photo_001, photo_002, and so on, keeping each file’s extension. Set FOLDER to your folder, then run python rename.py from a terminal.
This free converter translates Python code into equivalent JavaScript. It is useful for developers who learned Python first and now need to write JavaScript, or anyone porting a backend script to a Node.js or browser environment. Paste your Python and get clean, readable JavaScript output instantly.
How to Convert Python to JavaScript
Paste your Python code
Copy your Python code and paste it into the input box, or describe the Python logic you want converted.
Click Generate
The AI analyzes the Python syntax and semantics and produces equivalent JavaScript code, handling common translation patterns automatically.
Review the output
Read through the JavaScript carefully. Pay attention to places the AI has flagged as needing manual review — some Python patterns have no direct JS equivalent.
Test the JavaScript
Run the converted code in a browser console (F12 → Console) or a Node.js environment. Verify the output matches what your Python code produced.
Adjust as needed
If the output is not quite right, re-run with more context or manually tweak the result. Use the converter as a starting point, not a final answer.
About This Python to JavaScript Converter
Python and JavaScript are both popular, beginner-friendly languages, but they have significant syntax and runtime differences. This converter helps you bridge them — whether you are moving a data processing script to Node.js, rewriting a backend utility for a browser extension, or simply learning how Python concepts map to JavaScript equivalents.
Here are the most important differences to keep in mind after converting. In Python, indentation defines code blocks — there are no curly braces. In JavaScript, curly braces {} define blocks. The converter handles this automatically, but the visual structure of the code will look different.
Python uses print() for output; JavaScript uses console.log(). Python lists become JavaScript arrays, and Python dictionaries become JavaScript objects. The syntax looks similar (both use square brackets for lists/arrays and curly braces for dicts/objects), but the built-in methods differ. For example, Python's list.append(x) becomes array.push(x), and Python's len(list) becomes array.length.
Python's range() function has no direct JavaScript equivalent. The converter typically rewrites range-based for loops as standard JavaScript for (let i = 0; i < n; i++) loops. Python list comprehensions ([x*2 for x in items]) are usually converted to JavaScript array.map() calls, which are equivalent in most cases.
Async code is another area requiring attention. Python's asyncio with async def and await has a counterpart in JavaScript's async/await syntax — the keywords are the same, but the underlying event loops work differently. In JavaScript, async functions always return Promises. The converter handles basic cases well, but complex asyncio patterns (task groups, queues) may require manual adjustment.
Class syntax is similar in both languages, but Python's self parameter (which you write explicitly in every method) becomes JavaScript's implicit this. Python's __init__ constructor becomes the constructor() method in JavaScript. Python's f-strings (f'Hello {name}') become JavaScript template literals (Hello ${name}).
After converting, always test the JavaScript output against known inputs before deploying. The AI does its best to produce correct, idiomatic JavaScript, but some Python libraries (like pandas, numpy, or Python's standard os module) have no browser-JavaScript equivalent and will require you to find a JS alternative like lodash or the Node.js fs module.
Frequently asked questions
Is this Python to JavaScript converter free?
Yes, fully free. No account, no signup, no usage limits.
Does it handle Python classes?
Yes. Python classes with __init__, methods, and inheritance are converted to ES6 JavaScript classes with constructors and methods.
What about Python libraries like pandas or numpy?
Those libraries are Python-specific and have no direct JavaScript equivalent. The converter will translate the code structure but you will need to find JavaScript alternatives for Python-specific libraries.
Will the converted code run in a browser?
If your Python code only uses basic language features (no OS calls, no Python-specific libraries), the converted JavaScript should run in a browser. Node.js is needed for file system operations.
Should I test the output before using it?
Always. AI-generated conversions are excellent starting points but may need small adjustments, especially for edge cases or complex logic. Test with sample inputs first.
Can it convert JavaScript back to Python?
This tool converts Python to JavaScript. For JavaScript to Python, use the JavaScript to Python converter.