How long does Box keep preview documents?

Hi Natalia, 

Welcome to the Box Community!

You may preview your files in Box as long as its stored and supported in Box.

Check out this article to learn more about Box Preview: https://support.box.com/hc/en-us/articles/360044195013-Introducing-Box-Preview

Best,

Using Box Preview API, does Box autodelete files after they were previewed or the files are kept in Box indefinitely? 

Hi Natalia, 

For questions related to Box API, I suggest posting this in our Platform and Developer Forum: https://support.box.com/hc/en-us/community/topics/360001932973-Platform-and-Developer-Forum and our members and experts would be happy to help with your concern.

Best,