js-dos
What js-dos is
js-dos is a JavaScript API and player for running DOS and Windows 9x programs in a browser or Node. It uses DOSBox or DOSBox-X, including DOSBox-X support for Windows 95 and 98 system images. Developers can add the player to a webpage from its CDN, install it from npm, or download it from GitHub releases. A basic setup needs static hosting, not a backend, and the page must be served over HTTP. The runtime works in a browser or Node, in a worker or render thread, and is available in WebAssembly and pure JavaScript versions. Browser IPX networking supports server creation and peer and alias connections. Progress is stored locally by default, though browser storage may be wiped; cloud saves require a subscription and secret key. All users can read sockdrive storage, while subscribers can write to it. The site describes accelerated 3Dfx rendering and mobile support as production for v7 but still in progress for v8.
Who it suits
js-dos suits developers and users who want to run DOS or Windows 9x programs in a browser or Node. It also supports self-hosting and browser-based IPX networking.
What it does well
- Free core features.
- Supports DOSBox and DOSBox-X backends.
- Runs in browsers and Node.
- Offers WebGL-backed accelerated 3Dfx rendering.
- Supports browser IPX networking.
What to know first
- A webpage must be served over HTTP.
- Browser-stored progress may be wiped.
- Cloud saves and sockdrive writing require a subscription.
- Mobile support for v8 is still in progress.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| js-dos | Core features are stated to be free; subscription activates cloud saves and enables write access to sockdrive drives | Free |
| Cloud saves subscription | Activates cloud saves; subscribed users can write to sockdrive drives | On request |
As js-dos.com lists them, read 5 Oct 2026. The maker's own page has the final word.
Verdict
js-dos offers several ways to run DOS and Windows 9x programs, with browser and Node runtimes and networking support. Check the storage terms before relying on saved progress: browser storage may be wiped, and a shared secret key grants direct access to drives and saves, where concurrent writing can cause corruption.
Facts from js-dos's own pages
- Deployment limitation
- The documented sockdrive service has one active deployment in Europe, and the site says performance can vary by region. · js-dos.com, 5 Oct 2026
- Emulation
- It supports DOSBox and DOSBox-X backends, including Windows 95/98 system images through DOSBox-X. · js-dos.com, 5 Oct 2026
- Graphics
- The site describes WebGL-backed accelerated 3Dfx rendering as a unique capability. · js-dos.com, 5 Oct 2026
- Hosting
- A basic player needs static website hosting and does not require a backend; the page must be served over HTTP rather than opened with the file protocol. · js-dos.com, 5 Oct 2026
- Integration
- js-dos can be added to a webpage from its CDN, installed from npm, or downloaded from GitHub releases. · js-dos.com, 5 Oct 2026
- Maker
- The about page credits @caiiiycuk as maker and does not state a headquarters or founding date. · js-dos.com, 5 Oct 2026
- Mobile status
- The overview labels mobile support as work in progress for v8 and production for v7. · js-dos.com, 5 Oct 2026
- Networking
- Its browser IPX networking uses WebRTC-NET and supports IPX server creation, peer and alias connections, and shared network instances. · js-dos.com, 5 Oct 2026
- Persistence
- Game progress is stored locally in the browser by default, and the site says browser storage may be wiped; cloud saves can be enabled with a secret key. · js-dos.com, 5 Oct 2026
- Purpose
- js-dos provides a JavaScript API and player to run DOS and Windows 9x programs in a browser or Node. · js-dos.com, 5 Oct 2026
- Runtime
- The product supports execution in browsers and Node, works in a worker or render thread, and offers WebAssembly and pure JavaScript versions. · js-dos.com, 5 Oct 2026
- Security detail
- The site warns that a shared secret key grants direct access to the account's disk drives and saves, and concurrent writing can quickly corrupt them. · js-dos.com, 5 Oct 2026
- Self-hosting
- The site documents running a custom sockdrive server locally or globally on Linux distributions such as Ubuntu. · js-dos.com, 5 Oct 2026
- Sockdrive
- All users can read sockdrive storage, while subscribers get write access to save progress and install games; disk cloning and unlimited disks are listed features. · js-dos.com, 5 Oct 2026
- Storage integration
- The player supports custom save storage through filesystem change hooks, and local persistence is based on OPFS. · js-dos.com, 5 Oct 2026
- Support
- The about page directs users to open a GitHub issue or ask the maker on Twitter for questions and suggestions. · js-dos.com, 5 Oct 2026
Where js-dos stands on Freedom251
- MS-DOS Emulators#9 of 26