--- title: "Free fill-in (Kriss-Kross) generator with answers | Once Books" description: "A free fill-in (Kriss-Kross) generator that makes a printable puzzle and its answer in one click. Every puzzle fits exactly one way, with no sign-up and no watermark." source: "https://www.oncebooks.com/tools/fill-in-generator" --- 1. [Home](https://www.oncebooks.com/) 2. [Tools](https://www.oncebooks.com/tools) 3. Fill-in generator Free tool # Free fill-in generator, with the answer Pick a size and generate a fill-in puzzle, then print it with its answer. Every puzzle fits exactly one way, with no sign-up and no watermark. It runs on the same engine as our KDP Publisher Studio. PuzzleDesign Difficulty A bigger grid holds more words to place. Every puzzle fits exactly one way. 13×13 grid. Fit all 15 words into the grid so every crossing agrees. Theme ClassicBoldSoftShadedNavyIndigoSkyTealEmeraldForestPlumBerryCrimsonEmberAmberCocoa **Customise colours** Block squares Cell borders Frame Cell fill Letters & numbers Page background Style StandardClean Clean drops the title band and footer, leaving the grid. Generate puzzlePrint / save PDF Two pages: the empty grid with its word bank, and the filled answer. Every puzzle fits one way, checked by the same engine as our KDP studio. ## Want the whole book? This makes one puzzle. Sign up to turn it into a full Fill-in book for Amazon KDP: hundreds of graded puzzles at any trim, as print-ready PDFs. [Build the full book](https://app.oncebooks.com/publisher-studio/fill-in/edit?from=fill-in&v=2&s=eyJkaWZmaWN1bHR5IjoiTUVESVVNIiwiY29sb3JUaGVtZSI6eyJ0aGVtZUlkIjoiY2xhc3NpYyIsIm92ZXJyaWRlcyI6e319fQ) Free to build · pay once to export Preview The skeleton with its word bank, and the filled answer. Hide the preview - Fill-in Medium 3 BAT · PEA · PIE 5 FINCH · FROST · GREEN · HEART · PROUD 7 HEXAGON 8 NOTEBOOK · REINDEER · SKELETON 9 CROCODILE · SNOWFLAKE · SURPRISED 1 Puzzle - Fill-in Medium · Solution 3 BAT · PEA · PIE 5 FINCH · FROST · GREEN · HEART · PROUD 7 HEXAGON 8 NOTEBOOK · REINDEER · SKELETON 9 CROCODILE · SNOWFLAKE · SURPRISED 2 Solution Generate puzzlePrint / save PDF ## How to make a fill-in puzzle 1. Pick a difficulty. Choose a grid size. A bigger grid holds more words to place, so the solve takes longer. 2. Generate the puzzle. Press Generate puzzle. You get a crossword skeleton and a word bank, proved to fit exactly one way. 3. Print the two pages. Press Print / save PDF. You get two pages: the empty grid with its word bank, and the filled answer. ## How to solve a fill-in Fit every word from the list into the grid so that all the crossings agree. There are no clues: the words and the shape are what you have. ### The method 1. Start with the rare lengths. Count how many slots and how many words there are of each length. A length with only one word has only one home, so place it first. 2. Work the crossings. Every white square where two slots meet must hold the same letter in both words, which rules most candidates out fast. 3. Cross words off as you go. Each word is used once. Strike it from the list when placed, so the remaining choices shrink. 4. Let one letter cascade. A placed word fixes letters in every slot it crosses, which often forces the next word, and the next. **The one rule** Every word from the list goes in once, and all crossings agree. **What the answer page shows** The fully filled grid is printed at the back. **How the grades differ** Bigger grids hold more words and more crossings to track. **Good for** Solvers who like a crossword without the trivia. ## Publishing a whole book? This tool makes one puzzle for home or the classroom. To make a fill-in book you can sell on Amazon KDP, Publisher Studio generates hundreds of graded puzzles from a themed word bank, at any KDP trim, as a print-ready interior and solutions PDF. [See the KDP fill-in maker](https://www.oncebooks.com/kdp-fill-in-maker) ## Questions **What is a fill-in puzzle?** A fill-in (also called Kriss-Kross) is a crossword with no clues. You are given the grid and a list of words, and you fit every word in so that the letters where words cross agree. It is solved by logic, not trivia. **Is this fill-in generator free?** Yes. Pick a difficulty, generate a puzzle and print it with its answer, with no sign-up and no watermark. It is free for classroom, home and personal use. **Does every puzzle have one solution?** Yes. Every puzzle is generated and checked by the same engine our Publisher Studio uses, so the word list fits the grid exactly one way. A puzzle is never ambiguous. **Does it include the answer?** Yes. Every puzzle prints as two pages: the empty grid with its word bank on page one, and the filled grid on page two, so you can check your work. **What size are the pages?** The free tool prints at 8.25 by 11 inches, a popular large-print size. Our Publisher Studio will export the same book at any KDP trim, from 5.06 by 7.81 up to 8.27 by 11.69, as a print-ready 300 DPI interior. Short of ideas? Browse our [ready-made printables for this puzzle](https://www.oncebooks.com/fill-in) and print one today.