WebNES
WebNES is a free JavaScript Nintendo Entertainment System emulator that runs in web browsers, using HTML5 canvas and optimization for Chrome’s V8 engine.
What WebNES is
WebNES is a free JavaScript Nintendo Entertainment System emulator that runs in web browsers, using HTML5 canvas and optimization for Chrome’s V8 engine. A playable release build is linked through GitHub Pages, and the project can run without a build step. Its README estimates that approximately 98% of games should work with common NES mapper formats. Graphics use WebGL with a canvas fallback, including selected shaders such as CRT monitor emulation, while audio uses the HTML5 WebAudio API. Players can remap keyboard controls, use game pads, quick-save and quick-load states, capture screenshots, switch between NTSC and PAL, load ZIP ROMs, vary game speed, and use a Game Genie code database. Trace logs for CPU instructions and PPU events support ROM and emulator developers. The project is MIT-licensed. Internet Explorer is unsupported because of performance issues and missing real typed arrays. Pete Ward says it began in 2013 as a port of his C++ emulator.
Good
- Free browser-based NES emulator
- Estimated support for approximately 98% of games
- Supports WebGL and CRT-style shaders
- Includes remappable controls and game pads
- Offers quick save and load states
Watch out
- Internet Explorer is unsupported
- Optimized for Chrome’s V8 engine
- Requires ROM files for game loading
- Build setup requires npm and Bower
Who it suits
WebNES suits players who want browser-based NES emulation with save states, controller options, shaders, and cheat codes. Developers can also use its CPU and PPU trace logs.
Verdict
WebNES offers a broad set of browser emulation controls, graphics options, save features, and developer tracing tools at no cost. Internet Explorer users are excluded, and Chrome is the stated optimization target.
The facts
Each one read from WebNES's own pages, with the date it was checked.
What it does
- Audio
- Audio support uses the HTML5 WebAudio API.checked 4 Oct 2026
- Build requirements
- The project can run without building; building requires npm and Bower, and the README provides Windows and Linux build instructions.checked 4 Oct 2026
- Compatibility limit
- Internet Explorer is explicitly unsupported because of performance issues and its lack of real typed arrays.checked 4 Oct 2026
- Controls
- Keyboard keys can be remapped, and game pads are supported.checked 4 Oct 2026
- Controls and saves
- Features include remappable keyboard keys, game pad support, and quick save and quick load save states.checked 4 Oct 2026
- Developer feature
- The emulator can generate trace logs for CPU instructions and PPU events for ROM authors or other emulator authors.checked 4 Oct 2026
- Development tools
- Trace logs for CPU instructions and PPU events are available for ROM authors and other emulator authors.checked 4 Oct 2026
- Game compatibility
- It supports common NES mapper formats, and the README estimates that approximately 98% of games should work.checked 4 Oct 2026
- Game Genie
- A database of Game Genie codes lets players activate or deactivate known codes for a loaded game.checked 4 Oct 2026
- Graphics
- It supports WebGL with a canvas fallback and includes selected shaders such as CRT monitor emulation.checked 4 Oct 2026
- Graphics and audio
- It supports WebGL with canvas fallback, selected shaders including CRT monitor emulation, and audio through the HTML5 WebAudio API.checked 4 Oct 2026
- License
- The repository identifies its license as MIT.checked 4 Oct 2026
- Other player features
- It supports screenshots, NTSC and PAL, ZIP ROM loading, variable game speed, and a Game Genie code database.checked 4 Oct 2026
- Product
- WebNES is a JavaScript NES emulator built with HTML5 canvas and optimized for Chrome's V8 engine.checked 4 Oct 2026
- Project history
- Pete Ward’s profile says WebNES was started in 2013 and was originally ported from his C++ NES emulator.checked 4 Oct 2026
- Save states
- Quick save and quick load are supported.checked 4 Oct 2026
Where it runs
- Browser demo
- The maker links to a playable release build hosted on GitHub Pages.checked 4 Oct 2026
- Browser limitation
- The README says Internet Explorer is entirely unsupported because of performance issues and its lack of real typed arrays.checked 4 Oct 2026
The company
- Maker and audience
- Pete Ward describes himself as a game development software engineer and calls WebNES his browser NES emulator written in JavaScript.checked 4 Oct 2026
- Maker background
- Pete Ward’s GitHub profile describes him as a game development software engineer with over 20 years of coding experience.checked 4 Oct 2026