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The team brings you another container release featuring:

  • regular and timely application updates
  • easy user mappings (PGID, PUID)
  • custom base image with s6 overlay
  • weekly base OS updates with common layers across the entire ecosystem to minimise space usage, down time and bandwidth
  • regular security updates

Find us at:

  • Blog - all the things you can do with our containers including How-To guides, opinions and much more!
  • Discord - realtime support / chat with the community and the team.
  • Discourse - post on our community forum.
  • Fleet - an online web interface which displays all of our maintained images.
  • GitHub - view the source for all of our repositories.
  • Open Collective - please consider helping us by either donating or contributing to our budget

linuxserver/emulatorjs pulls GitHub Stars GitHub Release GitHub Package Repository GitLab Container Registry Docker Pulls Docker Stars Jenkins Build LSIO CI

Emulatorjs - In browser web based emulation portable to nearly any device for many retro consoles. A mix of emulators is used between Libretro and EmulatorJS.


Supported Architectures

We utilise the docker manifest for multi-platform awareness. More information is available from docker here and our announcement here.

Simply pulling should retrieve the correct image for your arch, but you can also pull specific arch images via tags.

The architectures supported by this image are:

Architecture Available Tag
x86-64 amd64-<version tag>
arm64 arm64v8-<version tag>

Application Setup

The Backend can be accessed at:

The first thing you will need to do is click to download the default art/configs from this interface, this will setup a skeleton directory in your /data mount. From there add roms to the respective roms directories and follow the on screen instructions to add them to your web frontend running on port 80.

The frontend application has been initially optimized around being used with a standard gamepad (more specifically for modern Xbox consoles that have chromium based Edge browsers). The navigation revolves around the up/down/left/right keys to browse the menus and launch games. Mobile browsers will function, just keep in mind compatibility will be reduced especially for CD based games.

Currently only n64 is using an EmulatorJS core. I understand there may be some confusion as to project naming, but when this project (linuxserver/emulatorjs) started it was meant to be a simple frontend for self hosting folks to use the at the time deobfuscated code of that ethanaobrien was working on. Since then EmulatorJS has evolved into it's own amazing project based on Libretro cores that have been highly optimized to function for web. Also since then I tried to roll my own cores, which while fuinctional have fallen out of maintenance as they are all pinned back to the Retroarch 1.11.0 days and comprise the majority of the systems. So in general despite the naming of this project and the logo this is just a docker container with a web based backend for generating a useable self hosted emulation website and is in no way affiliated with EmulatorJS outside of using their n64 core.

For Xbox users please click the select button a couple times after launching a game to ensure the B button does not trigger a "back" action in the browser. (official name "view button" it is the two small squares) Exiting the controller mode and back to browser controls can be triggered by holding the start button for 3 seconds. (official name "menu button" the three lines) You will be unable to use features like save states and modify controller layouts on the emulatorjs based emulators currently as I have not determined a methodology of re-entering controller mode once you exit it. All normal game saves will function given you exit the game play screen cleanly using the B button for back this includes multi disc games for psx. Your game saves are stored in browser storage by hostname so if you make any changes to your local hosted setup (port or IP) the saves will not follow with it. For libretro based emulators you can use the button combination start+select+L+R to access the libretro menu and change settings/save or load/etc.

We know about most of the oddities like crackling sound for some emulators, rendering issues, and games unreliably auto launching to fullscreen. In general full CD games on the Xbox web browser do not seem to work due to their size if you have a chd/pbp less than 450 megs it will run. Edge on Xbox has some kind of undocumented ram limitation of about a gigabyte. Until all emulators are transitioned to libretro cores the oddities of using self hosted EmulatorJS will not be something that can or should be solved using hacky workarounds interacting with obfuscated code. Just keep in mind these are full blown machine emulators running in Javascript in a browser, do not expect bare metal performance.

This container (outside of the profile functionality) only generates a static set of files that can be hosted on any web provider even object storage. Eveyrthing runs in the clients browser and there are no dependencies on this container. To extract/copy this website it is at the path /emulatorjs/frontend inside the container. If you are happy with the catalouge you have created and no longer want to run stuff like the IPFS backend or want to upload these files to some other hosting provider you can simply copy the contents of that directory and kill off this container.

Mounting in existing rom directories can be achieved by pointing to the default folder structure, IE lets say you would like to mount your NES library:

-v /path/to/nes/roms:/data/nes/roms

The folder names are:

  • 3do
  • arcade
  • atari2600
  • atari7800
  • colecovision
  • doom
  • gb
  • gba
  • gbc
  • jaguar
  • lynx
  • msx
  • n64
  • nds
  • nes
  • ngp
  • odyssey2
  • pce
  • psx
  • sega32x
  • segaCD
  • segaGG
  • segaMD
  • segaMS
  • segaSaturn
  • segaSG
  • snes
  • vb
  • vectrex
  • ws


To help you get started creating a container from this image you can either use docker-compose or the docker cli.

docker-compose (recommended, click here for more info)

version: "2.1"
    container_name: emulatorjs
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
      - SUBFOLDER=/ #optional
      - /path/to/config:/config
      - /path/to/data:/data
      - 3000:3000
      - 80:80
      - 4001:4001 #optional
    restart: unless-stopped

docker cli (click here for more info)

docker run -d \
  --name=emulatorjs \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Etc/UTC \
  -e SUBFOLDER=/ `#optional` \
  -p 3000:3000 \
  -p 80:80 \
  -p 4001:4001 `#optional` \
  -v /path/to/config:/config \
  -v /path/to/data:/data \
  --restart unless-stopped \


Containers are configured using parameters passed at runtime (such as those above). These parameters are separated by a colon and indicate <external>:<internal> respectively. For example, -p 8080:80 would expose port 80 from inside the container to be accessible from the host's IP on port 8080 outside the container.

Parameter Function
-p 3000 Rom/artwork management interface, used to generate/manage config files and download artwork
-p 80 Emulation frontend containing static web files used to browse and launch games
-p 4001 IPFS peering port, if you want to participate in the P2P network to distribute frontend artwork please forward this to the Internet
-e PUID=1000 for UserID - see below for explanation
-e PGID=1000 for GroupID - see below for explanation
-e TZ=Etc/UTC specify a timezone to use, see this list.
-e SUBFOLDER=/ Specify a subfolder for reverse proxies IE '/FOLDER/'
-v /config Path to store user profiles
-v /data Path to store roms/artwork

Environment variables from files (Docker secrets)

You can set any environment variable from a file by using a special prepend FILE__.

As an example:

-e FILE__MYVAR=/run/secrets/mysecretvariable

Will set the environment variable MYVAR based on the contents of the /run/secrets/mysecretvariable file.

Umask for running applications

For all of our images we provide the ability to override the default umask settings for services started within the containers using the optional -e UMASK=022 setting. Keep in mind umask is not chmod it subtracts from permissions based on it's value it does not add. Please read up here before asking for support.

User / Group Identifiers

When using volumes (-v flags), permissions issues can arise between the host OS and the container, we avoid this issue by allowing you to specify the user PUID and group PGID.

Ensure any volume directories on the host are owned by the same user you specify and any permissions issues will vanish like magic.

In this instance PUID=1000 and PGID=1000, to find yours use id your_user as below:

id your_user

Example output:

uid=1000(your_user) gid=1000(your_user) groups=1000(your_user)

Docker Mods

Docker Mods Docker Universal Mods

We publish various Docker Mods to enable additional functionality within the containers. The list of Mods available for this image (if any) as well as universal mods that can be applied to any one of our images can be accessed via the dynamic badges above.

Support Info

  • Shell access whilst the container is running:

    docker exec -it emulatorjs /bin/bash
  • To monitor the logs of the container in realtime:

    docker logs -f emulatorjs
  • Container version number:

    docker inspect -f '{{ index .Config.Labels "build_version" }}' emulatorjs
  • Image version number:

    docker inspect -f '{{ index .Config.Labels "build_version" }}'

Updating Info

Most of our images are static, versioned, and require an image update and container recreation to update the app inside. With some exceptions (ie. nextcloud, plex), we do not recommend or support updating apps inside the container. Please consult the Application Setup section above to see if it is recommended for the image.

Below are the instructions for updating containers:

Via Docker Compose

  • Update images:

    • All images:

      docker-compose pull
    • Single image:

      docker-compose pull emulatorjs
  • Update containers:

    • All containers:

      docker-compose up -d
    • Single container:

      docker-compose up -d emulatorjs
  • You can also remove the old dangling images:

    docker image prune

Via Docker Run

  • Update the image:

    docker pull
  • Stop the running container:

    docker stop emulatorjs
  • Delete the container:

    docker rm emulatorjs
  • Recreate a new container with the same docker run parameters as instructed above (if mapped correctly to a host folder, your /config folder and settings will be preserved)

  • You can also remove the old dangling images:

    docker image prune

Via Watchtower auto-updater (only use if you don't remember the original parameters)

  • Pull the latest image at its tag and replace it with the same env variables in one run:

    docker run --rm \
      -v /var/run/docker.sock:/var/run/docker.sock \
      containrrr/watchtower \
      --run-once emulatorjs
  • You can also remove the old dangling images: docker image prune

warning: We do not endorse the use of Watchtower as a solution to automated updates of existing Docker containers. In fact we generally discourage automated updates. However, this is a useful tool for one-time manual updates of containers where you have forgotten the original parameters. In the long term, we highly recommend using Docker Compose.

Image Update Notifications - Diun (Docker Image Update Notifier)

tip: We recommend Diun for update notifications. Other tools that automatically update containers unattended are not recommended or supported.

Building locally

If you want to make local modifications to these images for development purposes or just to customize the logic:

git clone
cd docker-emulatorjs
docker build \
  --no-cache \
  --pull \
  -t .

The ARM variants can be built on x86_64 hardware using multiarch/qemu-user-static

docker run --rm --privileged multiarch/qemu-user-static:register --reset

Once registered you can define the dockerfile to use with -f Dockerfile.aarch64.


  • 09.08.23: - Rebase to Alpine 3.18, migrate to s6v3.
  • 06.07.23: - Deprecate armhf. As announced here
  • 24.11.22: - Update IPFS links for chdman.
  • 04.04.22: - Ingest pre-built chdman bins during build time.
  • 23.02.22: - Update ingestion point for emulatorjs bins.
  • 25.01.22: - Allow users to mount in existing rom directories.
  • 14.01.22: - Add profile paths and rebase to Alpine 3.15.
  • 04.01.22: - Add headers needed for Threaded emulators.
  • 29.11.21: - Add wasm mime type to NGINX.
  • 26.11.21: - Configure IPFS in a lower power mode, use homebuilt blobs for emu cores.
  • 19.11.21: - Pin retroarch version.
  • 14.11.21: - Update default cores to ingest.
  • 23.10.21: - Initial release.