RunMat
GitHub
MATLAB online alternative

Run MATLAB-syntax math in your browser

RunMat executes MATLAB-syntax code locally in your browser with GPU acceleration when available. No account, no license server, no install.

Open Browser SandboxDownload RunMat

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Why people look beyond MATLAB Online

MATLAB Online runs through MathWorks-hosted compute in the browser. Basic access is free; full access depends on a linked license. Basic access includes 20 hours per month with 15-minute continuous compute and 15-minute idle-time limits. As of May 2026. That is convenient for some work, but engineers and students still hit friction:

Account barriers

Sign-up process and license requirements create unnecessary friction for quick tasks.

Idle timeouts & hour caps

Basic access includes 20 hours per month with 15-minute continuous compute and 15-minute idle-time limits. As of May 2026.

Cloud dependency

Code must be uploaded to remote servers, raising privacy and connectivity concerns.

No local GPU access

Computation runs on MathWorks-hosted resources, so your laptop or workstation GPU is not the execution target.

Toolbox access depends on license

Basic MATLAB Online includes a limited set of commonly used products. Full product access depends on your license. As of May 2026.

No built-in agent

MathWorks' Agentic Toolkit connects supported AI coding agents to local MATLAB installs through MCP. RunMat puts the agent inside the same browser runtime as your workspace and plots.

Meet RunMat: no license required

RunMat is an open-source runtime for MATLAB-syntax math. In the browser, your code runs on your own device through WebAssembly, with GPU acceleration in browsers that support WebGPU.

Built-in agent

Describe the math, or paste an existing MATLAB script. The agent writes new code or rewrites around toolboxes and builtins RunMat doesn't yet ship. Every change comes back as a diff.

No account required

Open the sandbox and start coding immediately. No sign-up, no license key.

Client-side execution

Your code compiles to WebAssembly and runs locally in your browser. Nothing leaves your device unless you save to the cloud, and after the initial page load it works offline.

GPU acceleration on any vendor

Metal on Mac, Vulkan on Linux, DirectX 12 on Windows. WebGPU in the browser. No CUDA dependency.

Learn more

Interactive 2D & 3D plotting

GPU-rendered surfaces you can rotate, zoom, and pan. Plots live in the same computation chain as your math.

Type & shape tracking

Hover any variable to see its dimensions. Mismatched matrix sizes get red underlines before you run.

Open Browser Sandbox

An engineering team, working alongside you

RunMat's agent writes MATLAB-syntax code, runs it in the same runtime, inspects workspace and plot state, and returns each change as a reviewable diff.

Runtime-aware inspection

Checks tensors for NaN, verifies shapes against expected dimensions, and reads plot data from any 3D camera angle.

Every change is reviewable

Edits are presented as diffs. Accept or reject each change. Conversations are stored as searchable project files.

See what the agent can do

Try a prompt in the browser

Open a runnable sandbox session with starter code and an agent prompt already loaded.

Animate a wave surface

Visualize two interfering waves on a square membrane and animate the surface.

Sweep an oscillator

Turn this damped oscillator into a parameter sweep and overlay the results.

Debug a shape error

Debug a matrix dimension mismatch, explain the fix, and return corrected code.

How it works

Get started in three simple steps.

1

Open the sandbox

Go to runmat.com/sandbox. The editor loads in your browser; no account or license needed.

2

Write code, or ask the agent

Type MATLAB-syntax code directly, or describe what you want to compute and let the built-in agent write it for you.

3

Run and iterate

Execute on the RunMat runtime with GPU acceleration when available. Inspect plots and variables, then iterate until the math is right.

Every change versioned. No git required.

Every save creates a version automatically. Per-file history and full project snapshots are included on all App tiers include a free sandbox and a Pro trial for persistent projects. Pro adds project sharing with your team -- no git setup or merge conflicts.

Automatic file history

Browse the timeline and restore any previous state. No commits, no staging area.

Learn more

Project snapshots

Capture your entire project in one click. Restore instantly, even across terabyte-scale datasets.

Learn more

App project sharing

Share projects with colleagues instantly. No shared drives, no emailing files back and forth.

Learn more

The fastest runtime for your math

RunMat runs math faster because of how the runtime is engineered. Fusion merges sequential operations into fewer GPU steps; residency keeps your arrays on-device between steps. That means less memory traffic, fewer program launches, and faster scripts.

How fusion worksSee the benchmarksHow GPU results are validated

RunMat vs. MATLAB Online

RunMat runs MATLAB-syntax code in your browser or desktop app with a built-in agent and local GPU acceleration when available. MATLAB Online runs through MathWorks-hosted compute. Basic access is free; full access depends on a linked license. Basic access includes 20 hours per month. As of May 2026.

RunMat

Open-source runtime with a built-in agent

  • ✓Open-source runtime (Apache 2.0)
  • ✓No account or license required
  • ✓Built-in agent
  • ✓Agent reads workspace variables and 2D/3D plot scenes
  • ✓Client-side execution
  • ✓Cross-platform GPU (Metal, Vulkan, DX12, WebGPU)
  • ✓Works offline
  • ✓Interactive 2D & 3D plotting
  • ✓Real-time type & shape tracking
  • ✓Execution tracing & diagnostics
  • ✓Automatic file versioning & snapshots (App)
  • ✓Agent rewrites scripts around unsupported toolboxes & builtins
  • –Limited package / toolbox support
  • –Subset of MATLAB functions

MATLAB Online

MathWorks' cloud-hosted MATLAB IDE

  • –Basic access is free; full access depends on a linked license. As of May 2026.
  • ✕Account & sign-in required
  • ✕No built-in agent
  • ✕Basic access includes 20 hours per month with 15-minute continuous compute and 15-minute idle-time limits. As of May 2026.
  • ✕Cloud-based execution
  • ✕No local GPU access; computation runs on MathWorks-hosted resources
  • ✕Requires internet connection
  • ✓Full MATLAB language
  • ✓Complete toolbox ecosystem
  • ✓Official MathWorks support
  • ✕No built-in file versioning

What works today

Core matrix workflows, plotting, and debugging ship today. Here is what is in progress.

Works well
•

Matrix and array operations (indexing, slicing, reshaping)

•

Arithmetic, logical, and relational operators

•

Control flow (if/else, for, while, switch)

•

User-defined functions with multiple outputs

•

Cells, structs, and basic classdef OOP

•

400+ built-in functions

•

20+ plot types (plot, scatter, surf, mesh, contour, contourf, imagesc, bar, pie, stem, quiver, area, errorbar, plot3, semilogx/semilogy/loglog, and more) with GPU acceleration, subplots, figure handles, and interactive 3D camera

•

Real-time type and shape tracking (hover to see matrix dimensions)

•

Live syntax validation (red underlines for dimension mismatches and errors)

•

Execution tracing and diagnostic logging

•

Async code execution (non-blocking runs)

Limitations & future work

In progress

•

Extensible package support (signal processing, optimization, etc.)

•

Some edge-case MATLAB semantics

Not supported

•

Simulink or graphical block diagrams

•

MATLAB-specific file formats (.slx, .mlapp)

•

Java/COM interop

For toolboxes and builtins in the “in progress” list above, the built-in agent can often rewrite scripts to use what RunMat already ships, usually preserving the intent.

For a detailed list, see the language coverage guide and function reference. For workflow guides, browse resources or read our deep dives on GPU acceleration and the FFT family in RunMat.

Built for teams

SSO & SCIM

Integrate with your identity provider. Provision and deprovision users automatically.

ITAR-compliant deployment

Self-hosted, air-gapped option for export-controlled environments.

Open source & auditable

Apache 2.0 licensed runtime. Inspect every line of code that runs your math.

SOC 2 ready

Built to SOC 2 standards. Audit planned for Q4 2026.

See enterprise pricing

Frequently asked questions

Common questions about RunMat and MATLAB compatibility.

Is RunMat the same as MATLAB?⌄
No. RunMat is an independent project with an open-source runtime that executes MATLAB-syntax code. It is not affiliated with or endorsed by MathWorks, the makers of MATLAB.
Does RunMat have an AI assistant?⌄
Yes. RunMat ships with a built-in agent in the sandbox. You describe what you want to compute; the agent writes MATLAB-syntax code, runs it on the same GPU-accelerated runtime, reads workspace variables and 2D/3D plot scenes, and iterates. Every change comes back as a diff you can accept or reject.
Does MathWorks have an AI assistant?⌄
As of May 2026, MathWorks publishes the MATLAB Agentic Toolkit for Claude Code, GitHub Copilot, OpenAI Codex, Gemini CLI, and Sourcegraph Amp. MathWorks lists MATLAB R2020b or later, a supported AI coding agent, and Git as prerequisites, and its product page says the toolkit requires a local MATLAB installation and an AI service subscription. MathWorks' README says MCP servers must be used with MATLAB under the MathWorks Software License Agreement and must not be shared by multiple users; the repository license also limits the software to use with MathWorks products and service offerings.
How is RunMat's agent different from the MATLAB Agentic Toolkit?⌄
RunMat's runtime is open source under Apache 2.0 and runs without a MATLAB license. MathWorks documents the Agentic Toolkit as skills plus a MATLAB MCP Core Server connection to a local MATLAB installation and a supported third-party agent. The MCP Core Server exposes five built-in tools for static analysis, code evaluation, file execution, test execution, and toolbox detection; MathWorks also says MCP servers must not be shared by multiple users. RunMat ships the agent and runtime together in the browser, so the agent can inspect RunMat workspace variables, tensor shapes, and plot scenes directly.
Can I run my existing MATLAB scripts in RunMat?⌄
Many MATLAB scripts run without modification, especially those using core language features and common built-in functions. For scripts that use functions RunMat doesn't ship yet, the built-in agent can help adapt the code — running your script, reading the diagnostics, and proposing reviewable edits that replace unsupported calls with supported equivalents. Try your script in the sandbox; if something doesn't run, ask the agent to help adapt it.
Is RunMat really free?⌄
The RunMat runtime is open source under the Apache License 2.0. You can run MATLAB-syntax code in the browser sandbox without usage fees or time limits. Pro adds persistent projects, versioning, and project sharing -- see pricing.
Do I need to create an account?⌄
No. The browser sandbox works immediately without sign-up. Creating an account starts a Pro trial for persistent projects, file versioning, and project sharing.
Does RunMat work offline?⌄
Yes. Once the sandbox page loads, it can run code without an internet connection. For full offline use with local file access, download the RunMat desktop app or use the RunMat CLI.
How does RunMat run code in the browser?⌄
RunMat compiles to WebAssembly, which runs natively in your browser at near-native speed. For GPU-accelerated operations, it uses WebGPU (available in Chrome, Edge, Safari 18+, and Firefox 139+).
Is my code private?⌄
Yes. Code execution happens entirely on your device. Nothing is uploaded to run your script. If you sign in for cloud storage, files sync to RunMat's servers. Using the built-in agent sends context to the configured LLM provider.
Can RunMat use my GPU?⌄
Yes, in browsers that support WebGPU (Chrome, Edge, Safari 18+, and Firefox 139+). RunMat automatically offloads eligible operations to the GPU for faster execution.
What’s the difference between RunMat and GNU Octave?⌄
Both run MATLAB-style syntax, but RunMat is designed for performance (JIT compilation, GPU acceleration) and runs natively in the browser. Octave is a mature desktop application with broader toolbox compatibility but no browser-native execution.
Is there a desktop version?⌄
Yes. The RunMat desktop app provides the same interface as the browser sandbox with full local file system access. Download it from the download page, or use the CLI for local script execution.
Does RunMat support plotting?⌄
Yes. RunMat supports 20+ interactive plot types including plot, scatter, hist, histogram, surf, mesh, contour, contourf, imagesc, bar, pie, stem, quiver, area, errorbar, plot3, semilogx, semilogy, and loglog, all GPU-accelerated. 3D surface plots can be rotated, zoomed, and panned directly in the browser. See the plotting guide for runnable examples.

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