pgAdmin supports multiple languages using the Flask-Babel Python module. A list of supported languages is included in the web/ configuration file and must be updated whenever languages are added or removed with ISO 639-1 (two letter) language codes. The codes are named $LANG in this document.

Translation Marking

Strings can be marked for translation in either Python code (using gettext()) or Jinja templates (using _()). Here are some examples that show how this is achieved.


errormsg = gettext('No server group name was specified')


<input type="submit" value="{{ _('Change Password') }}">
<title>{{ _('%(appname)s Password Change', appname=config.APP_NAME) }}</title>
define(['sources/gettext', ...], function(gettext, ...){
    var alert = alertify.prompt(
        gettext('Password Change'),
        gettext('New password for %(userName)s', {userName: 'jsmith' }),

Updating and Merging

Whenever new strings are added to the application, the template catalogue (web/pgadmin/messages.pot) and the existing translation catalogues (web/pgadmin/translations/$LANG/LC_MESSAGES/messages.po) must be updated and compiled. This can be achieved using the following commands from the web directory in the Python virtual environment for pgAdmin:

(pgadmin4) user$ pybabel extract -F babel.cfg -o pgadmin/messages.pot pgadmin

Once the template has been updated it needs to be merged into the existing message catalogues:

(pgadmin4) user$ pybabel update -i pgadmin/messages.pot -d pgadmin/translations

Finally, the message catalogues can be compiled for use:

(pgadmin4) user$ pybabel compile -d pgadmin/translations

Adding a New Language

Adding a new language is simple. First, add the language name and identifier to web/

# Languages we support in the UI
    'en': 'English',
    'zh': 'Chinese (Simplified)',
    'de': 'German',
    'pl': 'Polish'

Then, create the new message catalogue from the web directory in the source tree in the Python virtual environment for pgAdmin:

(pgadmin4) user$ pybabel init -i pgadmin/messages.pot -d pgadmin/translations -l $LANG