# How to Set Collabora UI to German (Docker Install)

**URL:** <https://forum.collaboraonline.com/t/how-to-set-collabora-ui-to-german-docker-install/3764>\
**Category:** Installation & Configuration\
**Created:** [June 11, 2025, 6:55pm UTC](https://forum.collaboraonline.com/t/how-to-set-collabora-ui-to-german-docker-install/3764 "2025-06-11T18:55:00Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![eaccelera](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.collaboraonline.com/eaccelera/32/1737_2.png) [@eaccelera](https://forum.collaboraonline.com/u/eaccelera)\
**Post date:** [June 11, 2025, 6:55pm UTC](https://forum.collaboraonline.com/t/how-to-set-collabora-ui-to-german-docker-install/3764/1 "2025-06-11T18:55:00Z")

</div>

Hi everyone,

This is my first post here. I’ve read through the official documentation and several threads about localization, but I haven’t found anything that specifically addresses Docker-based installations of Collabora.

We’ve set up a working (mostly) integration between Seafile and Collabora for a client. Collabora is running in Docker. Seafile’s UI is successfully set to German, but Collabora’s interface remains in English despite our efforts.

Here’s how we’re currently starting the container:

docker run -t -d -p 9980:9980   
-e “extra\_params=–o:lang=de --o:langtag=de-DE”   
–restart always   
–cap-add MKNOD   
–cap-add SYS\_ADMIN   
–security-opt seccomp=unconfined   
-v /opt/collabora/config/coolwsd.xml:/etc/coolwsd/coolwsd.xml   
–name collabora   
collabora/code

We’ve also tried setting the browser’s preferred language to German, but that didn’t make a difference. The UI continues to show in English when opening documents.

Is there something we’re missing in the Docker config? Does the UI language depend on the WOPI host or a setting inside coolwsd.xml? Any guidance would be appreciated.

Thanks in advance for your help.

---

<div class="post-metadata">

**Author:** ![darshan](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.collaboraonline.com/darshan/32/2230_2.png) [@darshan](https://forum.collaboraonline.com/u/darshan)\
**Post date:** [June 12, 2025, 2:43pm UTC](https://forum.collaboraonline.com/t/how-to-set-collabora-ui-to-german-docker-install/3764/2 "2025-06-12T14:43:04Z")

</div>

Hello @eaccelera Welcome to collabora online forum 🙂

In Docker-based setups of **Collabora Online (CODE)**, the UI language is primarily determined **by the browser language** and **client request headers** , not directly by the `extra_params` or the `coolwsd.xml` settings in most cases.

#### 1. **Check Browser Language Headers**

Ensure the client (browser accessing the document) sends the correct language:

- In Chrome or Firefox:
  - Go to browser settings → Languages → Move **Deutsch (German)** to the top.

#### 2. **Set `lang` in WOPI host request (if possible)**

If you’re controlling or customizing the WOPI host (e.g. Seafile integration), the WOPI URL used to open the file **can include a `lang=de` parameter**. This helps force the UI language.

For example:

```auto
https://<your-collabora-domain>/loleaflet/2.0.13/loleaflet.html?WOPISrc=...&lang=de

```

> However, **not all WOPI hosts support** adding arbitrary parameters like `lang`. Seafile may not expose this easily.

I found this discussion in old post might be interesting to read : [Collabora CODE (with seafile) default language](https://forum.collaboraonline.com/t/collabora-code-with-seafile-default-language/1163)

---

<div class="post-metadata">

**Author:** ![eaccelera](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.collaboraonline.com/eaccelera/32/1737_2.png) [@eaccelera](https://forum.collaboraonline.com/u/eaccelera)\
**Post date:** [June 17, 2025, 3:10am UTC](https://forum.collaboraonline.com/t/how-to-set-collabora-ui-to-german-docker-install/3764/3 "2025-06-17T03:10:15Z")

</div>

Hi @darshan Thank you for the warm welcome and the detailed explanation.

I’ve already tried setting my browser’s language to German in both Chrome and Firefox, but the Collabora UI still defaults to English. I also attempted to force the language using a URL rewrite.

Specifically, on the NGINX side, I added a rule to append `&lang=de` to requests that didn’t already include a `lang=` parameter. Here’s the relevant part of my NGINX config:

```auto
location ^~ /loleaflet {
    proxy_pass https://127.0.0.1:9980;

    proxy_set_header Accept-Encoding "";
    proxy_redirect off;

    # Add &lang=de if not already present in the query
    if ($args !~ "lang=") {
        set $new_args "$args&lang=de";
        rewrite ^/loleaflet/(.*)$ /loleaflet/$1?$new_args break;
    }

    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto https;
}

```

However, this didn’t seem to have any effect on the UI language.

Since I’m using Seafile, which may not expose the ability to pass custom parameters like `lang=de` in the WOPI request, I’m wondering if there’s a known workaround — maybe by modifying how Seafile calls Collabora, or by injecting headers elsewhere?

I also appreciate the link to the older discussion and will go through it in case I missed something. If anyone has successfully enforced a default language in a similar setup (Collabora + Seafile via Docker), I’d really appreciate your input.

Thanks again!