Puzzle Studio
Choose a kind, a difficulty and how many you want. The puzzles are built in your browser and then handed to the solver of that kind, which is asked for two answers and has to come back with one. You get the file and the proof.
Puzzle Studio, a puzzle generatorBratislavaEleven kinds in the browser
- 11 kinds, 4 difficulty steps, up to 20 at a time
- slowest kind measured at 0.35 s a puzzle, most under 0.05 s
- nothing is uploaded: no account, no puzzle, no seed word
The band above is a field of empty grids of the kinds this page makes, drawn on one canvas. Nothing in it was solved and nothing in it has an answer: it is a background, not a puzzle. It stops moving if your system asks for less motion, and it stops entirely once it scrolls off the screen.
Make them now.
Everything below happens on this machine. The first batch takes a moment longer while the generator for that kind is fetched, then it is milliseconds.
Nothing made yet.
Press Generate and the puzzles appear here, one by one, each with the line that says a solver has been over it. The work runs on a thread of its own, so the page keeps answering while it goes.
Two a day free. Then 4.90 € a month.
VAT is in the price and Link, which runs the Stripe checkout, sends you the receipt. There is no account to make: the licence is a signed key kept in this browser, and you can paste it into any other browser you use.
Free
0 €no accountTwo puzzles a day, counted in this browser. Enough to see whether the puzzles are any good.
- every kind and every difficulty
- SVG, PNG at 300 dpi, print sheet
- the credit line stays on the picture
- personal use, not for a publication
Personal
4.90 €a monthNo daily limit, and the credit line becomes your choice. For home, a classroom or a club.
- unlimited puzzles, up to 20 in one batch
- never the same puzzle twice on your account
- printed handouts for your own group
- cancel in the Stripe portal at any time
Bulletin
19 €a monthEverything in Personal plus a print licence for one publication, and the weekly sheet by e-mail. Bulletin Pro is 39 € a month for three puzzles a week, easy, medium and hard, each a different type.
- print in one parish bulletin, newsletter or paper
- print and the digital edition of it
- the weekly sheet arrives every Monday
- if you already subscribe, it works here at once
The key is checked here, in the page, against a public key that is part of the file: an Ed25519 signature made by our licence service. Nothing about you is sent to check it.
Asked for two answers, allowed one.
A language model can write you a Sudoku that looks like a Sudoku. What it cannot do is tell you, truthfully, that the grid has exactly one answer, because deciding that is a search and not a sentence. That is the whole of the difference this page is built on.
Each kind here has two programs behind it: one that builds a puzzle and one that solves it by applying rules. The builder keeps a candidate only when the human style solver finishes it without ever putting in a value to see what breaks. Then, separately, this page throws that result away and starts again: it hands the finished puzzle to the same solver the free daily game uses, gives it only what you are given, and asks for up to two solutions. One solution and no guessing, or the puzzle is not shown at all. The milliseconds on the green line are that second run, measured on your machine.
The solver has a search budget, and if a puzzle ever exhausted it the page would say so rather than claim a proof it did not finish. Across every kind, difficulty and size on offer, the slowest check measured so far is about eighteen milliseconds.
The generators are not written for this page. They are the same files that run the free daily games and the same ones that typeset the puzzle books, so they have been solved by readers every day for a year.
What you can make.
Ten of them are the kinds the daily games and the books are made of. The eleventh, the logic grid, comes from the same workshop and is the one with words instead of a grid of numbers.
- BadgersKiller Sudoku: nothing filled in, the dotted cages carry the sums.
- MagpiesNonograms: the numbers along the edges give the runs, and the picture follows.
- OttersSlitherlink: one closed loop, where a number counts the sides of its cell the loop uses.
- SquirrelsKakuro: a crossword of sums, digits 1 to 9, none repeated inside a run.
- CranesHashi: join the numbered islands with bridges, never crossing, all connected.
- SwansMasyu: one loop, straight through the white circles, turning on the black ones.
- VolesNurikabe: every number is an island of that many cells, the rest is one sea.
- HedgehogsStar Battle: two stars in every row, column and region, none of them touching.
- HeronsNumberlink: join each pair with a path and use every cell of the grid.
- HaresAnti-knight Sudoku: two cells a knight's leap apart never hold the same number.
- DormiceLogic grid: clues in sentences, one arrangement that fits all of them.
All eleven have a free puzzle every day at arling.sk/games, with hints that explain the step instead of filling it in.
Before you pay.
What does verified actually mean here?
After a puzzle is generated, the solver belonging to that kind is run over it again from the beginning, given only what you are given, and asked to find up to two solutions. The puzzle is shown only when it finds exactly one and did not run out of its search budget on the way. The milliseconds on the green line are that second run, measured in your browser, not a number we typed in.
Does anything leave my browser?
The puzzles, the seed word and the counter never leave. There is no upload in this page: the generators and the solvers are JavaScript files your browser fetches once and then runs.
The requests this page does make, in full: its own files; one call to our licence service with a Stripe session id when you come back from paying, and one of the same about once a month to renew the licence; and the anonymous visit count that every page on arling.sk sends to our own Umami. No e-mail address, no puzzle and no count of what you generated is ever sent.
Can I get the same puzzle twice?
Not by accident. Every puzzle is made from a key, and the key carries your licence identity plus a counter that only ever goes up and is kept in this browser. One account therefore never repeats a key. If you clear site data the counter goes back to zero, so a repeat becomes possible again; activating your licence again restores the identity but not the counter, which is the honest limit of a promise made without an account on a server.
Typing a seed word turns the never repeat rule off on purpose. The same word gives the same puzzles for everyone, which is how two people print the same sheet without sending a file.
Are these the same puzzles as the daily games and the books?
They come out of the same generators but from a separate key space, which starts with studio: instead of a date or book:. So a studio puzzle is never a copy of a daily puzzle or a book puzzle by construction.
The honest limit: on the smallest grids only so many puzzles exist at all, so two different keys can land on the same one. On a 5 x 5 Numberlink that is a real possibility. From medium upwards it is not.
What may I do with the puzzles I make?
Free and Personal cover your own use: at home, in a classroom, in a club, including printed handouts for that group. On the free plan the credit line stays on the picture; on Personal it is a checkbox.
Putting a puzzle in a publication, a newspaper, a parish bulletin, a newsletter or anything you sell needs the Bulletin plan, which carries a print licence for one publication. If you already subscribe to Puzzle Post Bulletin, your licence works here the moment you open this page in the browser you activated it in.
Why is the free plan only two a day?
Because the page has to pay for itself and we would rather say that than dress it up. The count sits in your browser, not on a server, so clearing site data resets it and we will not know. It is a request, not a lock.
How do I cancel?
In the Stripe customer portal, with the e-mail address you paid with. The licence keeps working until the end of the period you have paid for, and the files you have already downloaded stay yours.
Can I get my money back?
By law, no, and it is fairer to say so before you pay. Digital content delivered at once with your consent carries no right of withdrawal: in Slovakia that is section 19 paragraph 1 letter m) of Act No. 108/2024 Coll., and across the EU Article 16 letter m) of Directive 2011/83/EU.
That is the law, not our answer to a problem. The free plan exists so you can judge the puzzles before paying. If something is broken, write to support@arling.sk and we will fix it or send the money back, because that is a different thing from changing your mind.
Which browsers does this need?
Anything current. The generation runs in a module worker, which Chrome, Edge, Firefox and Safari 15 and newer all have; where it is missing the same work runs on the main thread in small pieces instead, which is slower but not broken. Checking the licence signature needs Ed25519 in WebCrypto, which means Safari 17 and newer.
Colophon
- Publisher
- ARLing s. r. o., Ivanská cesta 32E, 821 04 Bratislava, Slovakia. Company ID 56583486, VAT ID SK2122352100.
- Who makes it
- Andrej in Bratislava looks after the products and the support and answers at support@arling.sk. Our own program typesets every page; the covers are commissioned and disclosed.
- Payment and delivery
- Stripe handles the sale through Managed Payments as the merchant of record, and ARLing supplies the files. At checkout you will see “Sold through Link”, your bank statement will show LINK.COM* ARLING, and Link sends you the receipt. After the payment the licence key is put straight into this browser, so the plan is on at once. No e-mail is sent from us and there is no account to make; on another computer you paste the same key by hand.
- Free allowance and terms
- Two puzzles a day are free, with no account and no e-mail. A plan is a signed key kept in your browser, and it can be cancelled in the Stripe portal at any time. Terms, withdrawal and privacy are public.