A word ladder is a sequence of words where consecutive words differ by one letter change. For example: CAT → COT → DOT → DOG.
Lewis Carroll invented word ladders as a kind of puzzle game; his 1879 Vanity Fair article proposed turning HEAD into TAIL with four words in between: HEAD → HEAL → TEAL → TELL → TALL → TAIL.
This tool lets you design your own word ladders, with a variety of different rules and constraints:
- Dictionary: Two dictionaries of English words are available:
- 10,000 English word list by Eric Price
- 370,000 English word list by dwyl — Warning: This currently makes the software run slow.
- You can also add your own extra words, or forbid words from the dictionary that you don't like. Click an × button to remove a word in the current ladder.
- Operations: In addition to allowing single letters replacements,
you can optionally enable:
- Swapping two adjacent letters.
- Inserting a new letter (increasing the word length).
- Deleting a letter (decreasing the word length).
- Objectives:
- You can specify a target word to reach, or just search for ladders from a start word.
- You can look for shortest ladders. With a goal, this finds the fastest way between two words. Without a goal, this finds a longest shortest ladder (the radius of the source in the graph).
- You can search among all ladders. In this mode, you see all the options available at each step, and you can choose which word to go to next. As a starting point, the ladder starts with the shortest one. Each word is labeled with the number of steps to the goal (if there is a goal), so you can tell which choices get you closer vs. farther away. This can be helpful for designing a word ladder of a desired length.
This software was originally created to design word ladders for a folded-paper and blown-glass sculpture called Brush With Words. For this purpose, it includes a link for rendering the current word ladder in our strip folding font.