Free Online Octave — MATLAB Alternative in Your Browser
GNU Octave itself, running in a browser tab: the MATLAB-compatible language for matrices, linear algebra, and numerical computing, compiled to WebAssembly and running in a full Jupyter notebook interface. No install, no account, nothing uploaded.
Octave
GNU Octave in your browser — the MATLAB-compatible numerical language, as a WebAssembly notebook.
First launch downloads ≈122 MB, then it's cached for a year. Nothing is uploaded — your files stay on this device.
Large download — best on a fast connection.
This is a desktop-class app — it works best on a larger screen.
Quick Answer
This free online Octave is the real GNU Octave 10.3 — the open-source numerical computing language that is syntax-compatible with most MATLAB code — compiled to WebAssembly by the emscripten-forge project and running in a full Jupyter notebook interface in your browser. You get matrices and linear algebra, solvers, loops and functions, Octave’s bundled m-file library, and inline plotting, all executing on your own device with nothing uploaded. It is a large environment (a ~120 MB first download), so give the first launch a moment — after that it is cached for a year. MATLAB is a registered trademark of The MathWorks, Inc., which is not affiliated with this page; Octave is the free, open-source alternative.
How It Works
Click Launch — the Octave environment (about 120 MB) downloads once and opens the notebook interface
Open the welcome notebook or create a new one — the Octave kernel starts automatically
Type MATLAB-style code — try A = [1 2; 3 4]; A*A — and press Shift+Enter to run a cell
Notebooks save in your browser; export them as files whenever you like
Key Facts
- The real GNU Octave 10.3 interpreter, not a reimplementation
- MATLAB-compatible syntax for most scripts and textbook code
- Full Jupyter notebook interface — cells, outputs, inline plots
- Octave’s bundled m-file library and math functions included
- Notebooks are saved in your browser — nothing is uploaded
- Free, open source (GPL-3.0), no account, no install
Frequently Asked Questions
Is this really Octave, and is it MATLAB-compatible?
It is really GNU Octave — version 10.3, the actual interpreter compiled from its C++ source to WebAssembly, not a JavaScript imitation. Octave is deliberately MATLAB-compatible: matrices, arithmetic, control flow, function files, and most textbook MATLAB code run unchanged. Some MATLAB-only toolboxes and newer proprietary functions do not exist in Octave, but for coursework, linear algebra, and numerical methods the two are largely interchangeable. MATLAB is a trademark of The MathWorks, Inc., which is not affiliated with this page.
How is this different from MATLAB Online?
MATLAB Online is the official, subscription-gated version running on MathWorks servers. This is the opposite architecture: the entire Octave interpreter runs as WebAssembly on YOUR device, so there is no account, no license, no session limit, and no server seeing your code — you can even keep working after disconnecting once it has loaded.
Can it plot?
Yes. The kernel renders plots inline in the notebook — open the bundled welcome notebook and run the sombrero and polar examples to see it. Plotting goes through a browser-friendly graphics backend, so the classic gnuplot-based workflows are replaced by interactive inline figures.
Where are my notebooks and files stored?
In your browser. The notebook interface stores files in the browser’s local storage on your device, and you can export or upload files at any time — nothing is sent to a server. Like any browser storage, clearing the site data clears the notebooks, so export anything you want to keep.
Why does the first launch take a moment?
The full Octave environment — interpreter, standard library, and math routines — is about 120 MB and downloads once. It is then cached for a year, so later launches start almost immediately. That is the price of running a complete numerical computing language entirely in a tab.
What are the current limitations?
This is the core Octave environment: the language, standard functions, and plotting all work, but Octave’s optional extension packages are not yet packaged for WebAssembly, and features that assume a desktop GUI or a shell are unavailable. For heavy production workloads the desktop version is still faster; for learning, coursework, and quick computations anywhere, this runs the real thing with zero install.