About Marrow

Marrow is a free 3D atlas of the human body, written for curious people rather than exam candidates.

If you have ever read a book like Bill Bryson's The Body and wished you could see the thing being described, this is for you. Rotate the body, peel it layer by layer, and tap any part to find out what it does, one fact worth repeating at dinner, and why it matters to you.

What's inside

• A 3D model of the whole body: skin, skeleton, muscles, organs, brain and nerves, heart and vessels, and ligaments.
• A short card for every part you can select: 279 full cards and 69 shorter ones.
• Search that understands everyday names: try "funny bone", "Adam's apple" or "six-pack".
• Guided tours that tell a story through the body.
• Links that open exactly the view you're looking at, so you can share it.

How the cards are written

Cards follow a published style guide. Every surprising fact cites a source. At this stage cards are drafted with AI help from well-established anatomy and are marked as awaiting a human fact-check; each card's Sources section says so. If you spot an error, every card has a Suggest a correction link.

What Marrow is not

Marrow explains how the body works. It isn't medical advice and can't diagnose anything. If you're worried about your health, talk to a doctor or pharmacist.

The body you're looking at

The 3D model is a single adult male reference body from the open Z-Anatomy and BodyParts3D projects. That means some parts, including the female reproductive organs, aren't shown yet, and real bodies vary much more than any one model can show.

Free, with no account

Marrow is free and has no accounts and no adverts. If you'd like to help it grow, see Keep Marrow growing.

Privacy

No accounts, no cookies, no adverts and no third-party trackers. If anonymous analytics are on, they count which features are used and which parts people open, never who you are. Exactly what's collected.