How to Use the Codeword Solver

Updated March 2026 Written by the Codeword Solver team Reviewed for accuracy against the live solver

What is a codeword puzzle?

A codeword (also called a code-cracker) is a crossword-shaped grid where every letter of the alphabet is replaced by a number from 1 to 26. There are no clues. Instead, you start with a small set of pre-revealed letter–number pairs and use logical deduction to fill in the rest.

The key rule: each number always maps to the same letter everywhere in the grid, and different numbers represent different letters. Once you decode number 7 as the letter R, every square labelled 7 becomes R. This cascade effect is what makes codewords solvable — and it is also the exact constraint that this Codeword Solver enforces when you enter a pattern.

How to enter a pattern

The solver uses four character types in a pattern:

A–Z
Known letters. Type the letter exactly as it appears in the grid. The solver will only return words with this letter in this position.
.
Unknown, unlinked position. A dot means "any letter, with no constraint." Use this when you know the position is blank but have no information about which letter it could be.
1–9
Unknown, coded positions. A digit represents one unknown letter from the codeword grid. Every position with the same digit must be the same letter, and different digits must represent different letters. If a digit appears only once in a pattern, it does not create a repeated-position clue by itself — but it still stands for one specific unknown letter and remains distinct from the other digit groups in that pattern.
?
Unknown, unlinked position (alternative). A question mark is identical to a dot — use whichever feels clearer in your pattern.
1

Choose the word length

Use the length dropdown to set the number of letters in your word. This controls how many input boxes appear — one per letter position.

2

Fill in the pattern

Enter a letter in any box where you know the letter already. Leave boxes blank (or enter a dot) for completely unknown positions. Use the same digit in every box that shares a codeword number — for example, if positions 2 and 5 are both numbered 14 in your grid, enter the same digit in both boxes. If two boxes have different codeword numbers, use different digits. In other words, 3422 means A B C C, not . . C C.

3

Choose a dictionary and search

Select Original for most puzzles. Click Search. Every result satisfies your positional letters and your linked-letter constraints simultaneously.

4

Review results by priority

Results are grouped to help you scan large candidate sets more easily. Most likely shows the strongest everyday, codeword-friendly candidates first. Possible shows additional valid matches that still fit the pattern. On very broad searches you may also see a lower-priority rare or obscure group. If too many words match, add more known letters, use linked digits accurately, or exclude letters you have already decoded elsewhere in the grid.

The Codeword Solver form showing a 7-letter pattern. The input boxes are filled left to right: C, then the digit 1 in positions 2 and 3 (indicating those two squares share the same unknown letter), then T, then three empty positions. The results panel below shows 2 matches: Coothay and Cooties.
Entering a pattern with linked positions: the digit 1 appears in two boxes, meaning those squares must be the same letter. The solver returns only words that satisfy this constraint — here, 2 matches for the pattern c11t…

Worked examples

Example 1 — known letters and a simple unknown

  • Situation: You know the word is 6 letters, starts with S, and ends with E. The other positions are completely unknown and unlinked.
  • Pattern: S....E
  • What the solver does: Returns every 6-letter word starting with S and ending with E.
  • Likely matches: scarce, source, sleeve, sponge, stance, strife, …
  • Next step: Cross-check against other decoded letters in the grid. If number 3 (position 3 in this word) is already decoded as O from another word, switch to S.O..E to narrow further.

Example 2 — linked positions (repeated codeword number)

  • Situation: You have a 5-letter word. Positions 1 and 4 share the same codeword number in the grid, and position 3 is already decoded as T.
  • Pattern: 1.T1.
  • What the solver does: Returns only words where position 1 and position 4 are the same letter, and position 3 is T.
  • Example match: altar
  • Why this matters: Entering ..T.. would return many 5-letter words with T in position 3, including words where positions 1 and 4 are different letters. That would break the actual codeword rule.
O

Original (111k words) — start here

Standard British English covering everyday and moderately specialist vocabulary. The right starting point for most people and most puzzles. Most mainstream UK newspaper and magazine codewords are solvable entirely within Original.

B

Big (362k words)

Adds rarer, archaic, technical, and specialist entries. Use only when Original returns nothing useful and you believe the puzzle setter has drawn on less common vocabulary — common in specialist publications, themed puzzles, and more challenging broadsheet supplements. Expect a longer results list and more manual filtering.

Definitions. Where a definition is stored for a matched word, it appears alongside the result. Not every entry has a stored definition, but where one exists it helps you evaluate whether the candidate makes sense in context.

Language coverage. Dictionaries cover British English as the primary standard. Where American English variants are codeword-safe — consistent spelling, unambiguous, appropriate for puzzle use — they are included alongside the British form.

Common mistakes to avoid

1
Using dots when positions are linked. If two positions share the same codeword number, enter the same digit in both — not a dot. A dot means "any letter, including different ones." The solver cannot enforce your linking constraint if you use dots.
2
Starting with long words. A 9-letter word with only two known letters returns hundreds of candidates. Decode short words first to get more letters, then return to long words with a richer pattern.
3
Using Big before Original is exhausted. Big includes many obscure words that are unlikely to appear in mainstream puzzles. Start on Original. Only switch to Big if Original genuinely returns nothing relevant.
4
Skipping cross-checks. Every time you decode a letter, immediately verify it is consistent with every other word that contains the same number. One wrong assumption compounds quickly.
5
Not using the Remove field. Once you have decoded several letters and know they do not appear in a particular word, entering them in Remove can cut a long results list to a handful of candidates in one step.

Why this is not a crossword or anagram solver

Crossword solvers and anagram tools handle different problems. This solver was built specifically for codeword logic:

  • Crossword solvers match patterns to dictionaries but do not enforce the linked-letter constraint — they return every word that fits length and known letters, leaving you to filter manually.
  • Anagram tools rearrange a set of letters you already have. In a codeword, you typically have positional information and linking constraints, not a complete set of letters.
  • This Codeword Solver enforces positional letters, digit-linked constraints, and removal exclusions in one pass. Results satisfy every rule you have described for the selected dictionary. Definitions are shown where available. See the methodology page for the full explanation of how matching, ranking, and dictionary curation work.

The Codeword Solver works best when you combine what you know — decoded letters, linked positions, and ruled-out letters — with steady grid cross-checking. Start with short words, confirm each new letter against the rest of the puzzle, and move up through Pocket, Original, and Big only when the narrower dictionary stops being useful.

Good luck with your puzzle.