How to Solve a Nonogram

Nonograms are logic puzzles where you fill squares in a grid to reveal a hidden picture. The numbers beside each row and above each column tell you which squares should be filled. With a few simple rules and logical solving techniques, you can solve Nonograms without guessing.

This guide explains how to play Nonograms, how to read the clues, and the best Nonogram solving strategies for beginners. Once you understand how the clues work, even larger and more challenging picture puzzles become much easier to solve.

What Is a Nonogram?

A Nonogram is a picture logic puzzle made up of a grid of empty squares. Numbers called clues are displayed next to the rows and above the columns. These clues tell you which groups of consecutive squares need to be filled.

When all the clues have been correctly solved, the filled squares form a picture or pattern. Nonograms are also known by names such as Picross, Griddlers, and Japanese crossword puzzles.

The puzzle can be solved entirely through logic. You do not need to guess which squares to fill.

How Do Nonogram Clues Work?

Understanding the clues is the most important part of learning how to solve a Nonogram.

Each number represents a group of consecutive filled squares. For example, a clue of 5 means that five squares next to each other must be filled.

If a row has the clue 3 2, it means there must be a group of three filled squares followed by a group of two filled squares. The two groups must have at least one empty square between them.

For example, a valid row for 3 2 could look like:

■■■□■■

The first group contains three filled squares, the second contains two, and the empty square separates the groups.

If a clue contains several numbers, the groups must appear in the same order as the numbers. However, there may be additional empty squares before, after, or between the groups.

Nonogram Rules

Before solving your first puzzle, remember these basic Nonogram rules:

• Each number represents a consecutive group of filled squares.
• Groups must contain exactly the number of squares shown by their clue.
• Separate groups must have at least one empty square between them.
• The order of the clue numbers must match the order of the groups.
• Every row and column must satisfy its clues.
• Squares that cannot be filled can be marked as empty.

The last rule is especially useful. Solving a Nonogram is not just about finding squares that must be filled. Finding squares that cannot be filled is equally important.

How to Solve a Nonogram Step by Step

1. Start With the Largest Clues

Begin with rows or columns containing large numbers. These clues often provide the most information because there are fewer possible positions for the required groups.

For example, if a row contains 10 squares and its clue is 10, every square in that row must be filled.

Even when a large group can move between several positions, some squares may overlap in every possible placement. Those overlapping squares can be filled immediately.

2. Look for Clues That Have Only One Possible Position

Some clues can only fit in one location. These are the easiest squares to solve and should be handled first.

If a row contains five squares and its clue is 5, the entire row must be filled. Similarly, if a column has exactly enough space for its clue groups, their positions can often be determined immediately.

3. Use Overlapping Squares

One of the most useful Nonogram strategies is identifying squares that must be filled regardless of where a clue's group starts.

Imagine a row with 10 squares and a clue of 7. The group of seven could start in several positions, but the middle squares overlap in every possible placement. Those overlapping squares are guaranteed to be filled.

This technique becomes increasingly useful as puzzles get larger.

4. Mark Squares That Must Be Empty

Once you know where a group ends, mark the next square as empty. This is important because separate clue groups must have at least one empty square between them.

Empty squares also prevent you from accidentally extending a group beyond the number specified by its clue.

If your Nonogram interface provides an empty-square or X marker, use it. Keeping track of known empty squares makes larger puzzles much easier.

5. Switch Between Rows and Columns

Nonograms are solved by constantly using information from both directions. A decision in a row can determine a square in a column, which can then reveal new information about another row.

After making progress on a row, check the affected columns. Then use the newly solved columns to return to the rows.

Think of the puzzle as a chain of deductions: row → column → row → column.

Understanding Overlapping Clues

Overlapping is one of the most powerful techniques for solving difficult Nonograms.

Suppose a row contains 10 squares and the clue is 7. The group of seven could occupy several positions, but the squares in the middle will be included in every possible placement.

Those guaranteed squares can be filled even though you do not yet know the exact starting and ending positions of the group.

Once those squares are filled, check the corresponding columns. They may provide enough information to determine additional squares in the original row.

How Multiple Nonogram Clues Work

Multiple numbers in a row or column represent multiple groups.

For example, the clue 2 4 means:

• A group of exactly two filled squares.
• At least one empty square.
• A group of exactly four filled squares.

The groups can have additional empty squares around them, but there must always be at least one empty square separating two different groups.

The same rule applies when a clue contains three or more numbers.

Common Nonogram Solving Mistakes

Guessing Too Early

A good Nonogram should be solvable through deduction. If you find yourself guessing frequently, look for additional information in the intersecting rows and columns before committing to a square.

Forgetting the Required Empty Space

Separate groups must have at least one empty square between them. Forgetting this rule is one of the most common beginner mistakes.

Ignoring Empty Squares

Empty squares are valuable information. Once a square is known to be empty, it can restrict the possible positions of clue groups and help solve both its row and column.

Only Looking at Rows

Every filled or empty square affects both a row and a column. If you get stuck, switch directions and examine the columns for new information.

Tips for Solving Nonograms Faster

• Start with the largest or most restrictive clues.
• Look for clues that nearly fill an entire row or column.
• Use overlapping groups to identify guaranteed filled squares.
• Mark known empty squares as soon as possible.
• Check both rows and columns after every significant deduction.
• Use completed rows to solve their intersecting columns.
• Avoid guessing when another logical deduction is possible.
• When stuck, look for a row or column where the remaining possibilities are highly restricted.

Nonogram Example

The examples below show how Nonogram clues correspond to filled squares and how a completed puzzle can reveal a picture.

What Happens When You Get Stuck?

Getting stuck is normal, especially when solving larger Nonograms. Instead of guessing, return to the clues and look for rows or columns where the remaining possibilities are limited.

Check whether a filled group has reached its required length. If it has, the squares immediately next to that group may need to be empty. You can then use those empty squares to narrow down the possibilities in the intersecting column or row.

Another useful approach is to find a row or column where several squares have already been solved. The remaining unsolved squares may have only one possible arrangement.

How to Get Better at Nonograms

The best way to improve is to solve puzzles regularly. Start with smaller, easier grids so you can become comfortable reading clues and recognizing patterns. As your solving skills improve, move to larger and more challenging puzzles.

Focus on solving logically rather than guessing. Over time, you will begin to recognize restrictive clues, overlapping groups, and useful empty spaces much faster.

Play Nonogram Online

Ready to put these techniques into practice? Play a free Nonogram puzzle online and use the numbered clues to reveal the hidden picture.

Choose your preferred difficulty to get started:

• Easy Nonogram Puzzles (5 × 5) – Perfect for beginners learning to read clues and solve simple picture logic puzzles.
• Medium Nonogram Puzzles (10 × 10) – Practice overlapping clues and develop more advanced solving strategies.
• Hard Nonogram Puzzles (15 × 15) – Take on larger grids that require careful reasoning and more complex deductions.
• Impossible Nonogram Puzzles (20 × 20) – Test your skills with our largest and most challenging Nonogram grids.

Start with an easier puzzle and work your way up to more challenging Nonograms as you develop your logic and picture-solving skills.

Frequently Asked Questions About Nonograms

What is a Nonogram?

A Nonogram is a logic puzzle where numbered clues tell you which groups of squares to fill in a grid. Correctly filled squares eventually form a hidden picture.

How do you read Nonogram numbers?

Each number represents the size of a consecutive group of filled squares. Multiple numbers represent multiple groups, and each group must be separated from the next by at least one empty square.

Do Nonograms require guessing?

No. Properly designed Nonograms can be solved using logical deductions. When you get stuck, examine the rows and columns for additional constraints instead of guessing.

What is the difference between Nonogram and Picross?

Nonogram and Picross generally refer to the same type of picture logic puzzle. Other names include Griddlers and Japanese crossword puzzles.

What is the easiest way to solve a Nonogram?

Start with the largest and most restrictive clues. Fill squares that are guaranteed by the clues, mark squares that must be empty, and repeatedly use the information from rows to solve columns and from columns to solve rows.

Can I play Nonograms online?

Yes! You can play free Nonogram puzzles online at several difficulty levels: Easy, Medium, Hard, and Impossible. Choose a difficulty and practice solving picture logic puzzles directly in your browser.