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XXI

XXI is a free daily number puzzle you play in your browser — no download, no account. One 4×4 grid a day, the same for everyone: draw a path that adds up to exactly 21. Longer path

Description excerpted from the original listing, which is linked below.

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Facts

Published: 17 Oct 2026 (yesterday)
Medium: web
Language: English (the page says so itself)
Subject: Games (read from the page)
First seen: 18 Oct 2026, 17:28 UTC

Built with

Not confirmed by us

The creator says they used AI.

What we can see

85 hygiene score

Certificate issued by WE1, 75 days remaining
Cookie attributes no cookies set
Credentials and payment does not ask for either
No strict transport security
Served over HTTPS
Mail authentication neither published
No insecure resources
Redirects none
Security headers 4 of 5 set
Third-party origins 6
Transport security TLS 1.3

Observed 18 Oct 2026 by fetching the page as a browser would. This describes hygiene and transparency, not safety: a missing header does not make a site dangerous, and a complete set does not make it trustworthy.

Made this?

Show it on your own site or README. It links back to this page.

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For a web page

<a href="https://bitsexplorer.com/i/3788753/xxi"><img src="https://bitsexplorer.com/badge/3788753.svg" alt="Featured on BitsExplorer" height="22"></a>

For a README (Markdown)

[![Featured on BitsExplorer](https://bitsexplorer.com/badge/3788753.svg)](https://bitsexplorer.com/i/3788753/xxi)

Changes we have seen

18 Oct 2026 first indexed

XXI

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