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If you want to provide a translation, it's recommended to first send an inquiry to or post a message on the forum to make sure that your language is not already being worked on.

Very little technical skill is needed to contribute a translation!

Starting OpenSesame with a specific language

By default, OpenSesame uses the default locale of your operating system if a translation is available, and falls back to English if a translation is not available. To start OpenSesame with a specific language, you can open change the Language option under Menu → Tools → Preferences.

How to translate

Translating Markdown tabs

How to translate Markdown tabs

Markdown tabs are the website-like tabs that present text and basic options. An example of a Markdown tab is the Get Started tab that you see when you launch OpenSesame.

To translate a Markdown tab, first locate the untranslated (English) .md file. In the case of the Get Started tab, this is:

  • opensesame_extensions\get_started\

Next, copy this original file to [original folder]\locale\[your locale code]\ So, if you're working on a French (fr_FR) translation, you would copy the original to (creating subfolders if they don't exist yet):

  • opensesame_extensions\get_started\locale\fr_FR\

Finally, simply open the to-be-translated in a text editor, and translate it.

A list of Markdown tabs that need to be translated

  • opensesame_extensions/update_checker/
  • opensesame_extensions/update_checker/
  • opensesame_extensions/update_checker/
  • opensesame_extensions/help/
  • opensesame_extensions/bug_report/
  • opensesame_extensions/bug_report/
  • opensesame_extensions/bug_report/
  • opensesame_extensions/after_experiment/
  • opensesame_extensions/system_information/
  • opensesame_extensions/get_started/
  • opensesame_extensions/opensesame_3_notifications/
  • opensesame_extensions/opensesame_3_notifications/
  • opensesame_extensions/opensesame_3_notifications/
  • opensesame_plugins/notepad/
  • opensesame_plugins/port_reader/
  • opensesame_plugins/repeat_cycle/
  • opensesame_plugins/quest_staircase_init/
  • opensesame_plugins/parallel/
  • opensesame_plugins/advanced_delay/
  • opensesame_plugins/joystick/
  • opensesame_plugins/reset_feedback/
  • opensesame_plugins/fixation_dot/
  • opensesame_plugins/touch_response/
  • opensesame_plugins/external_script/
  • opensesame_plugins/quest_staircase_next/
  • opensesame_plugins/video_player/
  • opensesame_resources/help/
  • opensesame_resources/help/

Translating the source code and user interface

Step 1: Download translatables.ts

translatables.ts is an XML file that contains all the strings that are to be translated. You can download it from here:

At the top-right of the file, you will see a 'Raw' link. Right-click on this link and select 'Save file as' (or something along those lines, depending on your browser) to save the file your disk.

Step 2: Install QtLinguist

QtLinguist is a graphical tool that will assist you in the translation process. It's very user friendly, and allows you to simply select a string of (English) text and enter a translation.

Windows and Mac OS

You can download QtLinguist as part of the Qt development toolkit or as a [standalone program] ( The standalone option is probably easiest for most people.


On Linux, QtLinguist is generally available in the repositories. For example, on Ubuntu it can be installed with:

sudo apt-get install qt4-linguist-tools

Step 3: Open translatables.ts in QtLinguist

Now start QtLinguist and open translatables.ts. You will first be asked to enter a source and target language. Leave the source as it is: 'POSIX/ Any country'. The target language should be set to the language that you will translate OpenSesame into. Leave the Country/Region option at 'Any country'. You can change these settings later via Menu -> Edit -> Translation file settings.

Now you can start translating! On the left you will see a list of 'contexts'. These indicate in which context the text is shown, which is helpful. To translate, simply click on the first source text-string in the first context, enter an appropriate translation, and press 'Control+Enter' to advance to the next string.

Some strings will contain HTML tags, like so:

Size<br /><i>in pixels</i>

In this case, only change the text and leave the HTML tags as they are. So, for a Dutch translation this would become:

Grootte<br /><i>in pixels</i>

Also, some strings contain wildcards, like so:

Tell me more about the %s item

These %s (and %d, %f, etc.) wildcards are blanks that are filled in on-the-fly by OpenSesame. Please respect these (removing a wild-card will crash the program!) and try to build an appropriate translation around them. So, for a Dutch translation this would become:

Vertel me meer over het %s item

Step 4: Compile your translation to .qm and test it

OpenSesame doesn't use the .ts file directly, but requires a file in .qm format. You can create this file easily from within Qt Linguist by selecting 'File -> Release as'. Create a .qm file with the same name (except for the extension) as the original file, and place it in the opensesame_resources/locale subfolder of the OpenSesame folder. So, for example, if you're working on a French translation, your original source file would be opensesame_resources/ts/fr_FR.ts and your compiled file would be opensesame_resources/locale/fr_FR.qm.

Once you have compiled your translation file to .qm format and placed it in the resources folder, run OpenSesame with your new locale as described at the top of this page.

Save and submit your translations

Send by e-mail

Once you are satisfied with your translations, send the translated .ts file and all translated md files to

Submit through GitHub

You can also submit (and update) your translation via GitHub. First, add your translation to your fork of OpenSesame, as opensesame_resources/ts/ll_RR.ts, where ll corresponds to the language and RR to the region. For example, en_US is US english, fr_FR is French, and zh_CN is Chinese. You can find a list of valid regions and languages here.

Similarly, add all translated .md files to your fork of OpenSesame.

Finally, submit a pull request to have your translation included in OpenSesame.

Updating an existing translation

The process to update an existing translation is similar to that described above for creating a new translation. The crucial difference is that you don't start with resources/ts/translatables.ts, but with a non-blank translation file, such as resources/ts/fr_FR.ts.

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