Multilingual event


An important feature of SlideSync is that it can handle multiple languages in parallel. This allows you to reach more viewers in the world and give them a better viewing experience. The viewer can switch between the different language versions both at the beginning and during the webcast. In addition to the audio output, all other elements of the viewer page are also displayed in the respective target language. SlideSync currently supports over 25 languages, including German sign language 

Quick start guide 

  1. Open the Settings menu.
  1. Check all the language versions you want to offer to your viewers. E.g. German and English for a bilingual webcast.
Menu: Einstellungen
  1. Scroll down to the “Encoding” option. Select “Other encoders” and confirm with the check mark.
  1. The streaming URLs for Main and Backup will appear, as well as the streamkeys for the selected languages. You must transfer these to your encoders accordingly.
MENU: Settings
  1. To check if the languages arrive correctly, start your encoders and let them clearly play different words, texts or music over the different language channels.
  1. Open the “Preview” menu, click on the sun symbol in the second menu column that now appears. The first language of the webcast will open. Press Play to control the stream.
Menu columns unfolded
  1. Repeat this for each additional language you produce. To do this, click on the top icon in the second menu column, the flag. There you will see all other language versions offered.
  1. Are you using slides? Load a separate set of slides into the system for each language, even if the content is the same (e.g. one English version for all spoken languages).
  1. Open the menu “Files.” Drag the presentations one by one to the plus icon, or click on it and then select the files in the file browser. You can load both PDF and PPT files into SlideSync. 
MENU: Files
  1. In the following query dialog click on “Presentation“.
  1. After the files are uploaded and transformed, you will see the thumbnails of the first slide. Each thumbnail corresponds to a slide set for one language.
  1. The slide sets still need to be assigned to the correct language and being activated. Click on each thumbnail one by one to view the details of the slide set. In each slide set, check and adjust the second line – “Language” – assign the language according to the language of the slide set. E.g. DE for the German slide set, and EN for the English one. Confirm by clicking the check mark.
  1. Further down the slideset has to be activated with the toggle switch. 
MENU: Files. Slideset details
  1. Back to the overview: at the end exactly as many slidesets must show a thin green frame around them as there are languages in the webcast. Then each language is assigned a slideset.
  1. The result of the assignment can be viewed again in the Preview menu and confirmed.
  1. advancing the slides during the webcast is done in the Live Producer. Only the slide set of the first language is displayed there. If you click on the next slide there, the slides in all other languages will also be switched automatically. 


SlideSync makes it easy to implement multiple languages via one webcast. The same webcast link is always valid for your viewers. At the beginning and during the webcast, the viewer can change the language in the playback at any time. At the same time, the language of the viewer’s user interface and the corresponding slides also change. 

On the production side, you need a separate stream for each language, consisting of a video signal and the associated audio signal. It is currently not possible to send only one video signal and several audio signals in parallel in one stream to SlideSync. Also a combination of one video stream and several separate audio streams is not possible. Therefore, with each additional webcast language, the requirement for a good internet connection multiplies, especially the upload rate! To make sure that each produced language arrives in the correct language channel on SlideSync, you need a unique streamkey for each stream. With the help of the unique streamkey SlideSync is able to correctly assign each speech sent to SlideSync. In addition to the moving images and sound, it is also important to pay attention to the slides. When using slides, you have the choice of creating a separate language version of the slide set for each target language, or using one slide set (for example, an English version) for all languages. Regardless of your decision, you must upload a separate slideset per language to Slidesync. 

The slidesets must be added in the “Files” menu. Load a file into the system one by one, either by dragging the file with your mouse onto the big plus symbol, or by clicking on that plus symbol and selecting the file in the following file dialog and clicking on “open”. A question dialog will follow. Click on “Presentation.” After the file has been loaded into the system, it may take several minutes until the slideset is processed – depending on the number and complexity of the individual slides. In the meantime, however, you can already assign the files to the target languages. Click on the preview image of the presentation. There you will see the details of the slideset. In the top line you see the original file name. Below that, the assignment to a language channel. For example, if the slideset is for the English language version, “en” for English should be selected here. If this is not the case, click on it and select “en” in the list that appears. Confirm the selection with the check mark. Further down you will see a button “Enabled.” This must be activated for the slideset to appear in the target language. Go back to the overview (click on the “Files” menu) and proceed in the same way with all further slidesets and for each further language. 

Controlling the slides is done via the Live Producer. There you will see the slideset of the first language. Control those as you are used to from monolingual webcasts – either by clicking in the border area of the large slide view, by clicking on the desired thumbnail in the timeline below or by clicking once in the center of the large slide view and then pressing the arrow keys (right/left) on your keyboard. Even if you only see the slideset of one language, all other languages are switched in parallel. 


  • Easy setup of the webcast platform for multilingual events. 
  • Control of the slides of all languages is done via one tool. SlideSync ensures that all languages switch slides simultaneously. 
  • Better audience experience and employee experience, through better integration of different nationalities in a company. 
  • Better communication with press around the world. Less miscommunication through translations into the target native language of the target countries. 


  • More complex setup in production, thus more costs. 
  • Multiple creation of slidesets with different languages may be required. 


  • Name the slides uniquely with a language abbreviation to facilitate assignment in Slidesync: 
  • e.g. “de_quarterly results_Q3.pdf”, “en_quarterly results_Q3.pdf”, “fr_quarterly results_Q3.pdf” etc.