Terms
Last updated 27 August 2026
Cortex is a daily puzzle game. It is free, it needs no account, and these terms are the short version of what you can expect from us and what we ask of you.
Using Cortex
Play as much as you like. Three puzzles are set each day, the same three for everyone, and they change at midnight in your own timezone.
We ask only that you do not:
- try to break, overload or probe the service, or access other players’ data
- automate play, or manipulate your score or rating by any means other than answering the puzzles
- republish the puzzles as your own
Sharing your result is encouraged — that is what the share button is for. Please do not spoil the answers for people who have not played yet.
Your account
You can play without signing up. An anonymous account is created for you automatically, and you can attach a Google account later so your progress follows you between devices. You may delete your progress at any time from your profile, and ask us to remove your account entirely by email. See the privacy policy for what is stored and why.
You are responsible for the Google account you sign in with. If you no longer control that account, contact us.
Cortex is not intended for children under 13. If you are under 13, please do not use it.
The rating is a game score
Cortex shows an ability rating and a percentile, and labels the display a “Cognitive Index”. That is a game score: it measures how you do against these puzzles, at these difficulties, on the days you played.
It is not an IQ score, not a validated psychometric instrument, and not a clinical or diagnostic measure of anything. Please do not treat it as one, present it as one, or make decisions on the strength of it.
What we do not promise
Cortex is provided as it is, without warranties. We try to keep it available, correct and fun, and we do not guarantee it will be any of those at a given moment. Puzzles are generated automatically, and while every one is checked by an independent solver before it is served, we cannot promise that no puzzle will ever be flawed.
We may change how Cortex works, add or remove features, reset scoring if it turns out to be wrong, or stop running the service. If we do stop, we will try to give reasonable notice.
To the extent the law allows, we are not liable for any loss arising from your use of Cortex. Nothing here limits rights you have that cannot be limited.
Ending things
You can stop using Cortex whenever you like, and delete your data as described above. We may suspend access if someone is doing the things listed under Using Cortex, or where we have to for legal or security reasons.
Changes to these terms
If these terms change in a way that matters, the date at the top changes with them. Continuing to play after that means the new version applies.
Contact
Questions about these terms, or anything else: kotsanas23@gmail.com.