Word Ladder Puzzles

One letter at a time, all the way across the language

A word ladder asks for something that sounds impossible and then turns out to be everywhere: a path between two words that never leaves the dictionary. COLD becomes CORD, becomes CARD, becomes WARD, becomes WARM — four small moves, each one a real word, and somewhere in the middle an opposite quietly turned into its opposite. The pleasure of the puzzle is discovering how close together English keeps its words: nearly every short word is one letter away from another, and the ladder is just you finding the staircase that was already there.

• 525 hand-picked ladders across three difficulties, each with a proven par
• 13,418 words you're allowed to climb through — any real word counts as a rung
• 1877 the Christmas Lewis Carroll invented the game for two bored young ladies

How this one plays

Every ladder deals you two words and a par — golf borrowed the word from Latin, and word-ladder players borrowed it from golf. Par is the shortest climb that exists: our generator walks every possible route through the whole accepted dictionary before a ladder is dealt, so when the game says par 4, it has proved that no three-step ladder is hiding anywhere. Match par and you've played the puzzle perfectly; the ⛳ in your share line says so.

The next rung always starts as a ghost copy of your current word. Tap the letter you want to change (or use the arrow keys), then type or tap its replacement — if that makes a real word you haven't already used, it clicks into place, with the changed letter picked out in teal. Undo and restart are free without limit, because backing out of a dead end is half the sport. Hint plays the next rung of the shortest route from wherever you are — free, but a hinted ladder can't set a best time, and best times only count clean, on-par climbs. Reveal shows the whole route and voids the ladder; the stats on this site only ever count honest solves. When you're done, copy a spoiler-free emoji result or a challenge link that hands a friend the exact same two words — the URL keeps them scrambled, and your address bar stays clean while you play.

The Christmas puzzle from the man who wrote Alice

Lewis Carroll invented the word ladder over Christmas 1877, for two young visitors who complained — his words — of "the having 'nothing to do.'" Asked for riddles, he had none, "and therefore set myself to devise some other form of verbal torture." The torture took. His diary soon records the game as Word-links; by March 1879 it was running in the London society magazine Vanity Fair under the name Doublets, with an epigraph lifted from the witches of Macbeth — "Double, double, toil and trouble." The two given words were the doublet, the words between them the links, the whole solution a chain.

The first three puzzles Carroll ever posed are period pieces in miniature: Drive PIG into STY. Raise FOUR to FIVE. Make WHEAT into BREAD. Vanity Fair ran Doublets as a weekly competition, scoring each doublet at as many marks as its two words had letters and docking marks for every extra link, with photograph albums for the season's champions. You can play Carroll's own openers above — PIG still drives into STY in five, and WHEAT still bakes into BREAD in six, along with FLOUR into BREAD, whose published six-step chain (through FLOOD and BLOOD — flour's route to bread apparently passes through a horror film) turns out, under modern exhaustive search, to have been perfect: no shorter route exists even today.

The argument Carroll had to settle — and we did too

Within weeks of the competition starting, Vanity Fair's puzzle column was drowning in disputes: competitors shortened their chains with words dredged from the dictionary's least-visited shelves, and the editor couldn't verify half of them. Carroll's fix was to publish his own Glossary — a list of words he was prepared to accept, so the game could be played "whether a dictionary is at hand or not."

Building this page, we hit exactly the argument he did, a century and a half later. Compute par over a tournament word list and some celebrated ladders technically shorten — Carroll's own showpiece, HEAD to TAIL, drops from his five steps to four — but only through words nobody would happily play. Our answer is a two-part promise rather than a smaller dictionary. You may climb through any of the 13,418 accepted words, obscure or not: knowing strange words should help you, never hurt you, and par is computed over all of them, so it's honest against the sharpest possible play. But no pair is dealt unless it can also be solved at exactly par using only everyday words — the hint button draws from that friendly route, and pairs that need dictionary junk to hit their minimum simply stayed out of the pool. Every ladder above passes both tests before you ever see it.

Word golf, and a novelist showing off

The game never stayed in one century or under one name — doublets, word-links, laddergrams, transformations; in the 1920s the inventor of the crossword, Arthur Wynne, even took out a patent on a step-word variant. But its best alias comes from literature. In Vladimir Nabokov's Pale Fire (1962), the deranged annotator Kinbote calls the game word golf and can't resist posting his personal records: "hate—love in three, lass—male in four, and live—dead in five (with 'lend' in the middle)." The novel's index even plays a round with itself, looping LASS through MASS, MARS and MARE to MALE. Try HATE to LOVE in three on paper and you'll discover why Kinbote was bragging — every three-step route leans on exactly the kind of dusty dictionary word our pool politely declines to require, which is why the ladder HATE→LOVE isn't dealt above. Some records are best left to fictional madmen.

The 5,757 words of Donald Knuth

A hundred and sixteen years after that bored Christmas, the word ladder got a second life as serious computer science. Donald Knuth, analysing algorithms at Stanford, built his Stanford GraphBase (1993) around a now-famous dataset: 5,757 common five-letter words, joined by an edge wherever two words differ by one letter. Word ladders turn out to be the perfect demonstration of breadth-first search — the ripple-outward algorithm that finds shortest paths — and they've been a staple of programming courses ever since. It's the same search this page runs to certify every par.

Knuth's graph came with poetry in its statistics. In his list, 671 words connect to nothing at all — change any single letter of ALOOF and you never get a word, so Knuth called them aloof words, and yes, ALOOF is one of them, standing off by itself along with EARTH, OCEAN, SUGAR and LAUGH.

Some pairs of words sit in separate islands of the graph entirely, so no ladder between them exists at any length. Every ladder dealt here lives safely inside the big connected continent — that's what the par proof guarantees.

Why five letters is a different sport than three

Measured against our own dictionaries, the three tiers aren't just longer words — they're different landscapes.

• 3 letters 15.9
• 4 letters 10.7
• 5 letters 5.7

Easy ladders play in a crowded city — the busiest three-letter word, TAT, has 34 neighbours on its own. By five letters the graph frays into ridgelines with real gaps between them, which is why hard pars run longer and why one wrong turn can strand you. You're not in the city any more; you're hiking.

The reliable techniques travel, though.

• Work both ends Solvers since Carroll have climbed down from the top and up from the bottom to meet in the middle. It halves how far ahead you have to see, which is most of the difficulty.
• C_RD Vowels are hinges Most long detours pivot on changing a vowel, because C_RD-shaped families — CARD, CORD, CURD — are where the crossroads live. When a rung feels like a dead end, try its vowel.
• Touch the letter you're protecting Everyone guards the letter the two ends share. The rung you refuse to touch is usually the one the shortest route runs straight through.

If you're enjoying this

The ladder's nearest cousins here are the anagram puzzles and the word scramble — those rearrange a word's letters all at once, where the ladder insists on one change at a time with every stop a real word. The same no-signup, play-forever philosophy runs through the themed word searches, the endless mini crosswords, the codewords and cryptograms for cipher-minded solvers, an unlimited word guessing game, and two genuinely daily puzzles — the daily word search and daily crossword — for when you want a streak with a calendar attached.