A small studio making calm puzzles that stay free

Who runs it

FreeInteract is an independent puzzle project based in the Netherlands. It is run as a one-person studio rather than a company with a staff list: the scenes, the generator, the fairness checks and the site itself are built and maintained by the same person, which is why every puzzle follows the same rules.

If something on the site is broken, unfair or unclear, writing to hello@freeinteract.com reaches the person who can actually change it, usually within 2 working days.

Why it exists

Most free puzzle sites are hostile: pop-ups over the playing area, a puzzle that turns out to hinge on a two-pixel shade change, an app install prompt before you have solved anything. Spot the difference is a lovely, quiet, twenty-second pleasure, and it deserved a home that treats it that way.

So the rules here are simple. The playing area is never covered by advertising. Puzzles are designed phone-first, playable with one thumb. Progress is yours and stays in your browser. Everything is free, and advertising pays the hosting bill rather than a subscription.

How the puzzles are made

Drawn scenes are generated from a seed, which means a puzzle URL always rebuilds the exact same scene on any device. That determinism is what makes solve times comparable and shared links trustworthy. Photo puzzles work differently: a real photograph is edited, then the two copies are compared pixel by pixel so that every counted difference is measurably visible rather than merely intended.

Before anything is published it has to pass automated fairness checks: enough measurable differences, every changed area at least thumb-sized, changes far enough apart to tap independently, every change fully inside the frame, and enough contrast to be seen by someone looking at it. Scenes that fail are repaired or thrown away, not published with a warning.

The long version of that process is written up in how we design a fair puzzle.

Who it's for

People with a spare minute: on a commute, in a waiting room, between two things that require more of them. There is no violence, no chat and no user-generated content, so it works for families as well as for players chasing a time on the leaderboard.