How to Solve Fill-In Puzzles: 7 Strategies That Work
Fill-in puzzles look deceptively simple — every answer is printed right there in the list — yet newcomers often stall on their first grid. The secret is that fill-ins reward a system, not luck. Here are the seven strategies experienced solvers use, from the moment the grid appears to the satisfying final entry.
1. Start with the longest words
The longest entries are your anchors. A nine-letter slot can usually only fit one or two words from your list, so it's the easiest place to commit. Work through the word list from longest to shortest and pencil in anything that clearly matches a slot of the same length.
2. Count every slot first
Before writing anything, scan the grid and note the length of each slot. Compare that against the word list grouped by length. If your list has three five-letter words and the grid has exactly three five-cell slots, you know the whole length group fits together — you just need to figure out which word goes where.
3. Use crossing letters as your main hint
Where a horizontal slot and a vertical slot meet, the shared cell constrains both. Once you place even one correct letter, every word crossing that cell gains a fixed letter. This is why fill-ins are best solved by working outwards from the first confirmed word, letter by letter.
4. Look for distinctive letters
Words with rare or repeated letters are easier to spot. In a word fill-in, a slot with a Q, X or Z visible in the crossings narrows things fast. In a number fill-in, keep an eye on which digits repeat — a slot that crosses another at a 7 twice in a row tells you a lot about the number hiding there.
5. Pencil lightly and stay flexible
You will change your mind. Write lightly (or use the printout's margin), and don't be afraid to erase a whole word when the crossings say it's wrong. A wrong word placed early blocks everything around it.
6. Work the edges and corners
Slots along the edge of the grid have fewer neighbours, which can make them easier to isolate — but they also get fewer crossing hints. Save the most heavily crossed, central slots for when you have more letters in place.
7. Use the answer key only when you're stuck
Half the fun is the aha moment. But if you're genuinely stuck, peeking at one answer and then solving the rest from it is a perfectly good way to learn. Every puzzle on this site has a show-answers button and a printable answer key for exactly that reason.
Practice makes progress
The best way to learn is to solve one every day. Generate a fresh word fill-in puzzle or a number fill-in puzzle in seconds, print it, and time yourself — you'll notice your speed improve within a week. New to the format? Start with our beginner's guide.