There isn't a way to do it directly on YouTube, so I wondered if there's a way to do it via the API? On the website, you can just filter videos that have captions, but if you want to search videos that have French captions for example, you can't.
Thanks a lot.
It seems it's not possible:
caption The caption parameter enables you to restrict a search to videos that have or do not have caption tracks: To only request videos that have captions, set the caption parameter value to true. For example, the URL below would retrieve videos that have captions and that match the search term "surfing":
https://gdata.youtube.com/feeds/api/videos?q=surfing&caption&v=2 Note: For backward-compatibility reasons, the API will also only return videos that have captions if you include the caption parameter but do not specify a parameter value.
To only request videos that do not have captions, set the caption parameter value to false. For example, the URL below would retrieve videos that do not have captions and that match the search term "surfing":
https://gdata.youtube.com/feeds/api/videos?q=surfing&caption=false&v=2 Note: The API will return an HTTP 400 response if you specify the parameter with any value other than true or false.
Source: https://developers.google.com/youtube/2.0/developers_guide_protocol#captionsp