A full-featured Python notebook that runs entirely in your browser — no server, no install, no cloud account needed.
Standout Features
No Python installation. No server. Run Python 3.11 instantly, inline.
Intelligent Python completions powered by the Jedi library, running entirely in your browser via Pyodide. Press Ctrl+Space or just type — completions arrive within 350 ms with colour-coded type icons for functions, classes, modules, keywords, and builtins. Zero latency. Fully offline.
Built-in Gemini 1.5 Flash panel with one-click actions: Explain Code, Explain Error, Suggest Plot, Generate Docstring, and free-form chat. Your code and key never leave your browser.
Free tier: 1,500 requests/day. Bring your own API key.
A transparent canvas floats over every cell — always on. Switch between Pen ✏️, Eraser 🧽, Stroke Eraser 🧹 and Pointer 👆 in one click. Strokes scroll with their cells and save together with your notebook in the .ipynf format.
A slide-in whiteboard panel for diagrams, typed note cards, and freehand sketches — right next to your notebook. Send any cell's code or rendered output to the pad with one click. Text cards support rich HTML including rendered markdown.
After every cell execution, PyNoteFlow scans your outputs for tables, arrays, and numeric data — then suggests the right chart type automatically. Click any suggestion to insert a ready-to-run matplotlib snippet. No typing required.
The .ipynf format bundles notebook cells, annotation strokes, and Writing Pad content into a single JSON file. Reopen it anywhere in PyNoteFlow and everything is exactly where you left it. Standard .ipynb compatibility is preserved: export a clean copy at any time.
Full Feature Set
Every feature works out of the box on first open.
Full Python runtime compiled to WebAssembly. NumPy, pandas, matplotlib, scikit-learn, SciPy and 200+ packages. First load ~8 MB, then fully offline.
Click ⚠ on any cell for instant static analysis — undefined names, unused imports, logic errors — with hover tooltips explaining each warning.
Toggle any cell (or all cells) to show code on the left and output on the right. Drag the splitter to set your preferred ratio.
Monitor up to 4 variables simultaneously. Pre/post bars above and below each cell show exactly how values change as the cell runs.
Python's input() works natively via SharedArrayBuffer + Atomics. An inline prompt widget appears in the cell output — no page freezing.
Inline PNG charts, styled DataFrames, HTML, Markdown, SVG, LaTeX math, audio player, video player, ANSI-coloured tracebacks.
Dark, Light, Monokai, Dracula, Tokyo Night, Nord, Gruvbox, Solarized, One Dark, and GitHub Light — switchable instantly, no reload. Every theme supports Dark, Light & Tint modes.
Classic — clean flat layout. Premium — elevated cards, gradient accents, glowing run button. Glass — frosted translucent surfaces with colour-glow borders. Combinable with any theme.
Connect to your own Colab session for GPU/TPU execution. Paste the URL + token — PyNoteFlow handles the Jupyter Messaging Protocol.
%pip install, %timeit, %time, %who, %whos, %reset, %env, %cd, %pwd, %%html, %%markdown, %%writefile, obj? and more.
Pip install panel with real-time progress, pip list, pip show, pip freeze, command history ring, spinner animation, offline caching.
Live table of all Python names, types, and values — updated after every cell execution. Opens as a side panel.
Rearrange any toolbar button via drag-and-drop. Order is persisted across sessions. Reset to default from Settings.
Up to 10 recent notebooks stored in IndexedDB with FileSystem handles. Reopen with zero clicks if permission was previously granted.
Notebook content auto-saved to localStorage every 30 seconds. Restored automatically on reload — zero work lost on crashes.
Export to self-contained HTML (with embedded dark/light toggle) or clean .ipynb. Never changes the current file.
In Action
Run the cell with Shift+Enter. Completions, linting, and AI explanations are one keypress away.
Keyboard-First
Full Jupyter-style command/edit mode, plus annotation and AI shortcuts.
How it compares
The only notebook that runs offline, annotates natively, and ships a built-in AI assistant.
| Feature | PyNoteFlow | JupyterLab | Google Colab | VS Code |
|---|---|---|---|---|
| No install / no server | ✓ | ✗ | ✓ | ✗ |
| Works fully offline | ✓ | ✓ | ✗ | ✓ |
| Live pen annotation | ✓ | ✗ | ✗ | ✗ |
| Annotations saved in notebook | ✓ (.ipynf) | ✗ | ✗ | ✗ |
| Writing Pad / whiteboard | ✓ | ✗ | ✗ | ✗ |
| Built-in AI assistant | ✓ | ✗ | ✓ | ✓ |
| Smart viz suggestions | ✓ | ✗ | ✗ | ✗ |
| Jedi autocomplete | ✓ | ✓ | ✓ | ✓ |
| Variable watch bars | ✓ | ✗ | ✗ | ✗ |
| input() support in browser | ✓ | ✓ | ✓ | ✓ |
| GPU / TPU support | ✓ (via Colab) | ✓ (local) | ✓ | ✓ (local) |
| Price | Free (limits) / $15 once | Free | Free / $10/mo | Free |
Free includes all features — just with weekly usage limits. Pro lifts every limit for a single $15 payment.
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