Is it possible to reduce images on the smartphone and how?

I do this on the notebook with the "reducer". Is that on the smartphone (Galaxy J7) too and how?

What to reduce? File size? Number of pixels?

File size and thus with images, the number of pixels

There are apps for it

Irfan view is also available for Android. So you can z. B. Save your pictures with larger jpg compression. The number of pixels remains, the file size is smaller, the pictures look rather nice. Out.

I do not need it myself. Is for the daughter of a good friend. I do not have the time to search and try for myself. Know me with smartphones only modest. Which apps exactly would you recommend?

Was intended for @jofischi, sorry!

I still answer 😆

I would try Photo Compress