Temporary file storage location (File Upload)

Hi everyone,

I would like to build a Streamlit app where data in 2 .csv files is compared, and based on some logic, the difference is shown as an output.
The issue is that the data in the files I am working can’t be stored outside of my computer, so I am trying to understand if I use the “file upload” functionality, whether this file will be stored temporarily in the cloud or not?

Can someone from the Streamlit team shed some light on it please?

Thank you in advance!

Hi @Negmat_Mullodzhanov -

Yes, if the app is deployed on Streamlit Cloud and you use file_uploader, the data will be transferred to the Streamlit Cloud image.


Hi Randy - Thank you for your response!

I would like to understand a bit more.

I saw this article on streamlit: Where does st.file_uploader store uploaded files and when do they get deleted? - Streamlit Docs

This seems to imply that the file is never stored on disk - only in memory. When you say the data is transferred to the “Streamlit Cloud image”, is it all happening in memory and deleted as soon as I close the app or the app reruns?

Please advise.

Thank you!

Yes, that is correct. The data is copied to the Streamlit Cloud image via file_uploader. But whether it resides in RAM (which it does) or not, that’s no longer “on your computer”. That data now exists temporarily on Streamlit Cloud.

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Hi Randy,

Thank you for clarifying!