description: "[Firefox](https://www.mozilla.org/en-US/firefox/) Browser, also known as Mozilla Firefox or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards."
[Firefox](https://www.mozilla.org/en-US/firefox/) Browser, also known as Mozilla Firefox or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.
We utilise the docker manifest for multi-platform awareness. More information is available from docker [here](https://distribution.github.io/distribution/spec/manifest-v2-2/#manifest-list) and our announcement [here](https://blog.linuxserver.io/2019/02/21/the-lsio-pipeline-project/).
Simply pulling `lscr.io/linuxserver/firefox:latest` should retrieve the correct image for your arch, but you can also pull specific arch images via tags.
**Modern GUI desktop apps have issues with the latest Docker and syscall compatibility, you can use Docker with the `--security-opt seccomp=unconfined` setting to allow these syscalls on hosts with older Kernels or libseccomp**
### Security
!!! warning
Do not put this on the Internet if you do not know what you are doing.
By default this container has no authentication and the optional environment variables `CUSTOM_USER` and `PASSWORD` to enable basic http auth via the embedded NGINX server should only be used to locally secure the container from unwanted access on a local network. If exposing this to the Internet we recommend putting it behind a reverse proxy, such as [SWAG](https://github.com/linuxserver/docker-swag), and ensuring a secure authentication solution is in place. From the web interface a terminal can be launched and it is configured for passwordless sudo, so anyone with access to it can install and run whatever they want along with probing your local network.
This container is based on [Docker Baseimage KasmVNC](https://github.com/linuxserver/docker-baseimage-kasmvnc) which means there are additional environment variables and run configurations to enable or disable specific functionality.
| PASSWORD | HTTP Basic auth password, abc is default. If unset there will be no auth |
| SUBFOLDER | Subfolder for the application if running a subfolder reverse proxy, need both slashes IE `/subfolder/` |
| TITLE | The page title displayed on the web browser, default "KasmVNC Client". |
| FM_HOME | This is the home directory (landing) for the file manager, default "/config". |
| START_DOCKER | If set to false a container with privilege will not automatically start the DinD Docker setup. |
| DRINODE | If mounting in /dev/dri for [DRI3 GPU Acceleration](https://www.kasmweb.com/kasmvnc/docs/master/gpu_acceleration.html) allows you to specify the device to use IE `/dev/dri/renderD128` |
| `--privileged` | Will start a Docker in Docker (DinD) setup inside the container to use docker in an isolated environment. For increased performance mount the Docker directory inside the container to the host IE `-v /home/user/docker-data:/var/lib/docker`. |
| `-v /var/run/docker.sock:/var/run/docker.sock` | Mount in the host level Docker socket to either interact with it via CLI or use Docker enabled applications. |
| `--device /dev/dri:/dev/dri` | Mount a GPU into the container, this can be used in conjunction with the `DRINODE` environment variable to leverage a host video card for GPU accelerated applications. Only **Open Source** drivers are supported IE (Intel,AMDGPU,Radeon,ATI,Nouveau) |
The environment variable `LC_ALL` can be used to start this container in a different language than English simply pass for example to launch the Desktop session in French `LC_ALL=fr_FR.UTF-8`. Some languages like Chinese, Japanese, or Korean will be missing fonts needed to render properly known as cjk fonts, but others may exist and not be installed inside the container depending on what underlying distribution you are running. We only ensure fonts for Latin characters are present. Fonts can be installed with a mod on startup.
The web interface has the option for "IME Input Mode" in Settings which will allow non english characters to be used from a non en_US keyboard on the client. Once enabled it will perform the same as a local Linux installation set to your locale.
If you run system native installations of software IE `sudo apt-get install filezilla` and then upgrade or destroy/re-create the container that software will be removed and the container will be at a clean state. For some users that will be acceptable and they can update their system packages as well using system native commands like `apt-get upgrade`. If you want Docker to handle upgrading the container and retain your applications and settings we have created [proot-apps](https://github.com/linuxserver/proot-apps) which allow portable applications to be installed to persistent storage in the user's `$HOME` directory and they will work in a confined Docker environment out of the box. These applications and their settings will persist upgrades of the base container and can be mounted into different flavors of KasmVNC based containers on the fly. This can be achieved from the command line with:
```
proot-apps install filezilla
```
PRoot Apps is included in all KasmVNC based containers, a list of linuxserver.io supported applications is located [HERE](https://github.com/linuxserver/proot-apps?tab=readme-ov-file#supported-apps).
#### Native Apps
It is possible to install extra packages during container start using [universal-package-install](https://github.com/linuxserver/docker-mods/tree/universal-package-install). It might increase starting time significantly. PRoot is preferred.
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.
| `--security-opt seccomp=unconfined` | For Docker Engine only, many modern gui apps need this to function on older hosts as syscalls are unknown to Docker. |
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](https://en.wikipedia.org/wiki/Umask) 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.
[](https://mods.linuxserver.io/?mod=firefox "view available mods for this container.") [](https://mods.linuxserver.io/?mod=universal "view available universal mods.")
We publish various [Docker Mods](https://github.com/linuxserver/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.
Most of our images are static, versioned, and require an image update and container recreation to update the app inside. With some exceptions (noted in the relevant readme.md), we do not recommend or support updating apps inside the container. Please consult the [Application Setup](#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:
```bash
docker-compose pull
```
* Single image:
```bash
docker-compose pull firefox
```
* Update containers:
* All containers:
```bash
docker-compose up -d
```
* Single container:
```bash
docker-compose up -d firefox
```
* You can also remove the old dangling images:
```bash
docker image prune
```
### Via Docker Run
* Update the image:
```bash
docker pull lscr.io/linuxserver/firefox:latest
```
* Stop the running container:
```bash
docker stop firefox
```
* Delete the container:
```bash
docker rm firefox
```
* 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)
We recommend [Diun](https://crazymax.dev/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:
