Adding closed captions

ThingLink allows you to upload closed captions to background 2D videos and videos uploaded to text & media tags. The captions are off by default, but the viewer can enable them by clicking or tapping the 'Closed captions' button. Check out the examples below!

• How to add captions to background videos
• How to add captions to videos inside text & media tags
• Supported file formats
• Limitatons & considerations

How to add captions to background videos

1. Start editing your ThingLink video
2. Select Settings
3. Scroll down and click 'Upload captions'
4. Select a compatible captions file from your device

If the captions were uploaded successfully, you'll see a closed captions button ('CC') next to the full-screen button in the bottom-right corner. Click the CC button and start the video:

How to add captions to videos inside text & media tags

1. Start editing your ThingLink project
2. Open the tag that contains an uploaded video
3. Hover over the video thumbnail on the left-hand side and click the ellipsis (three dots) button:
   
4. This will open up a new menu where you can upload or remove the closed captions. Simply click the 'Upload captions' button and select a compatible file from your device.

Once the file has been uploaded, your viewers will be able to enable the closed captions by hovering over the video and clicking the closed captions button. The exact button layout will depend on what browser they are using. 

Click the red tag below to check how this works!

Supported file formats

ThingLink currently supports two types of subtitle and caption files: SubRip (.srt) and WebVTT (.vtt). You can learn more about these file formats here and here.

Note that:

• the file must be encoded in UTF-8 (usually the default encoding for text files).
• ThingLink will ignore styling or position instructions included in the caption files.
• The file cannot contain more than 65000 characters. 

Limitations & considerations

• Closed captions can be uploaded to 2D videos only. It is not possible to upload captions for 360-degree videos yet. 
• Mobile & responsiveness considerations: captions take up a significant portion of the screenspace, so they may obstruct hotspots or significant parts of the video on mobile. You can instruct your viewers to view the videos in fullscreen if they'd like to use closed captions.

Troubleshooting

If you encounter an error when uploading a captions file or the file uploads but the captions do not appear, please share the link to your project and the captions file with our support team here.