Word Ladder Generator

Pick a start and an end word with the same number of letters. The generator finds the shortest chain of real words between them, changing one letter at a time, and prints it as a worksheet.

Try:

Loading the word list…

Why word ladders are great spelling practice

Each rung asks: which single letter can I change and still have a word? Students have to think about vowel sounds (COLD → CORD), consonant blends and letter position. It's phonics work that feels like a game, and it suits every level from three-letter CVC words (CAT → COT → DOT → DOG) to tricky vowel teams.

Tips for teachers

  • For early readers, use three-letter words and show every other rung as a hint.
  • Read each rung aloud as a class; the sound change is the learning.
  • Ask students to write a clue for each rung, turning the ladder into a mini crossword.
  • Challenge: can anyone find a ladder shorter than the one on the answer key? (They can't: it's already the shortest.)

How the shortest ladder is found

The computer tries every one-letter change of the start word and keeps the real words: that's step 1. Then every change of those words: step 2. Because it explores in rings, the first time it touches the end word, no shorter ladder can exist. Computer scientists call this breadth-first search.

Find a ladder to see its search rings.

Highlighted words are the ones on your ladder. Notice how fast the rings grow: that's why a computer can do in milliseconds what takes a person several minutes.

Questions teachers ask

What is a word ladder?

A puzzle invented by Lewis Carroll in 1877 (he called it "Doublets"): change one word into another by altering one letter at a time, and every step must be a real word. COLD → CORD → CARD → WARD → WARM.

Does the generator find the shortest ladder?

Yes. It searches outward from the start word one letter change at a time (breadth-first search), so the first time it reaches the target word, the path is as short as possible using its dictionary.

Why is there no ladder between my two words?

Both words must have the same number of letters, and every step needs to be a common English word. Some words have no one-letter neighbours at all, and longer words (six letters and up) rarely connect.

How do I print a word ladder worksheet?

Choose which rungs to show as hints and press Print. The worksheet shows the start and end word with empty rungs; the full ladder prints on the answer page.

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