➗ Math apps and platforms · 🎮 Learning games and sites
Krazydad
By Jim Bumgardner. Visit Krazydad
Desk research from the maker's own pages. Not yet tried by us. Checked 2026-10-24.
A one-person puzzle website running since 2005, with about two million free logic puzzles in more than 60 kinds: sudoku, kakuro, mazes, nonograms, Akari, killer sudoku and many inventions of its own. Puzzles can be printed as PDF books or played in the browser, and there is a daily set. Kid-friendly sections include Kidoku (4x4, 6x6 and 8x8 sudoku), printable mazes and starter books. Teachers, homeschoolers, hospitals and prisons may copy puzzles freely for non-commercial use.
Our take: A great free, ad-free source of printable logic puzzles for families and classrooms, with a parent choosing the right level for younger kids.
Checked in a browser
A browser check on 2026-10-25: what loads, the ads and trackers we saw, and what a child meets first. Not a hands-on test.
| Child safety: 4 out of 5 | No ads or chat on the first screen; links out go to Discord, PayPal and YouTube. |
|---|---|
| Data: 5 out of 5 | No ad, tracking or analytics networks loaded and no cookies were set. |
| Ease: 3 out of 5 | Many small puzzle tiles (92 kinds) with tiny phone and printer icons; there is a Kids filter, but a young child would need help choosing. |
| Cost honesty: 4 out of 5 | Free; a PayPal donation link and puzzle books are offered. |
What we found
- The first visit contacted 4 third-party hosts (Google fonts and jQuery) and set 0 cookies.
- No known ad, tracking or analytics network appeared.
- Filters include "Kids" and "Easy", and each puzzle shows whether it plays online or prints.
- Links out go to discord.gg, paypal.com and youtube.com.
From the test: A free, tracker-free puzzle site; the choice is large, so younger children will need help picking.
| Ages it suits | about 6 and up (privacy policy says the site is meant for 13+) |
|---|---|
| What its terms say about age | The privacy policy says the site, products and services are directed to people 13 or older and that it collects no information from anyone under 13. There are no separate terms beyond a copyright note. (terms) |
| Price | Free. Free; the author asks for optional donations (a suggested $10 via PayPal) and sells puzzle books (Oct 2026). |
| Works on | Web |
| Account | No account needed |
| Ads | None |
| In-app purchases | None |
| The AI in it | No AI; puzzles come from software the author wrote himself. |
What's good
- Huge free puzzle library with no ads or sign-up
- Printable books suit screen-free time
- Easy kid sizes of sudoku and mazes
- Run by a known, named puzzle maker
Watch for
- Privacy policy says it is meant for 13+, even though it has kids' puzzles
- Many puzzle types are hard and need an adult to explain the rules
- A hobby site that depends on one person
Data and privacy
No accounts. The site uses cookies only to remember puzzle settings and progress, and collects a name and email only if you contact the author or donate. Ads were removed in January 2018. Read the privacy policy.
Does it work?
No studies found. The author makes no learning claims; his puzzles appear daily in The New York Times as Two Not Touch.
In the Big Index
- On the list 18 best logic and puzzle games and apps for kids
Alternatives to Krazydad
Desk researchFree, with paid extrasNo ads
99math
99math (Estonia) · ages about 5-14 (grades K-8)
A low-effort, free way for teachers to make fact practice lively; parents of kids who dislike timed competition may want a calmer tool.
Desk researchFree, with paid extras
ABCya
ABCya.com LLC (a division of IXL Learning) · ages about 4-12 (pre-K to grade 6+)
Handy for quick grade-level practice in class or at home; skip if you want an ad-free experience without paying.
Desk researchPaidNo ads
Adventure Academy
Age of Learning, Inc. · ages grades 3-8 (about 8-13)
Good for kids who love online games and need a nudge toward school subjects; families wanting no social contact should set chat to off or choose a solo app.
Desk researchFree, with paid extras
Arcademics
Arcademics · ages about 6-14 (grades 1-8)
Fine for quick fact-fluency races at school or home; families who want no ad tracking or who have a child anxious about speed should skip it.
Desk researchFreeNo ads
Be Internet Awesome: Interland
Google · ages about 7-12
A good free starting point for online safety with kids 7-12, best paired with family talks since the game alone did not change behavior in testing.
Desk researchFreeNo ads
Blob Opera
David Li with Google Arts & Culture · ages about 4 and up
A delightful five-minute music toy for any age; not a music course.
Where these facts come from
- https://krazydad.com/
- https://krazydad.com/privacy/
- https://krazydad.com/about/
- https://krazydad.com/kidoku/
- https://blog.krazydad.com/2026/10/16/puzzles-and-the-ai-software-glut/
Prices, terms and features change. Nobody paid to be listed, nothing here is an affiliate link, and Peabody never rates itself. Where we and the maker disagree, the maker's own pages are the ones to trust.