The Instagram community has grown faster and become more global than we ever imagined. And we’re excited that you’ll soon be able to understand the full story of a moment, no matter what language you speak.
Captions and comments on posts in Feed, as well as the bio you include on your profile, are translated automatically based on the language they're written in and the language settings of the person viewing it. If your language is available as a translation, you can tap See Translation below the text to see it.
If translations aren't showing up, it could be because Instagram couldn't detect or doesn't currently support the language. Keep in mind that translations also may not show up for older posts and comments.
You can download Instagram from the App Store for free.