Is this something that can be done? I intend to get all the photos off it then take back to factory settings remove all apps etc as the battery life is getting worse. ! year old galaxy s6, will this help?

clean master works OK.

but a factory reset will bring it back to somewhere near original. Batteries do degrade however, though you can probably get a replacement battery installed if you send it/take it to a repair shop.

Factory reset will erase everything returning it “fresh from the box” state.

Not quite, but it removes most stuff without a proper dig around.

Not quite, but it removes most stuff without a proper dig around.

yeah, kinda fit for purpose I suppose, similar to a quick format, just deletes the address of your data, allowing an overwrite.