Photrain has some pre-defined rules that aim to engage visitors with the site. In addition to being the ones responsible for completing the site with photos, they also have the function of being the site's own moderators and deciding which photos will be the most prominent.

To maintain quality standards, a normal user will have the following restrictions:
- The maximum resolution allowed for photo upload is 1920 pixels wide and the minimum resolution is 1024 pixels wide;
- A user, by default, once registered on the site, will have at his disposal 10 (ten) uploading slots photos and a personal page (gallery) where all his photos will appear;
- Once all the slots are filled, the user will have to interact with the photos of the other users (like or dislike) to unlock more slots. This interaction can be done through the photo page or through the voting page;
- All photos and all users will have a ratio assigned (calculated from the number of likes, number of dislikes and number of views);
- Monthly (once a month) the system checks for photos with a ratio less than 50 % and converts these photos to a reduced JPEG format, 1024 pixels wide, and "remove" the photo from the public gallery of the site (the photo will only appear in the gallery/user's home page);
- When the user reaches the 100 (one hundred) photos on the site, the system checks if it already has many photos with a ratio of less than 50 % and, if so, it alerts the user to remove photos with few likes, as well as blocking the possibility of more photo uploads to the site.

By becoming Premium you will be able to upload photos without any restrictions:
- Unlimited slots for photo upload;
- Upload photos with a maximum 4K resolution (3840 pixels wide).

To become Premium, the user will have to pay a subscription (via PayPal). This subscription will also help keeping the site up and running and to implement new features.