Create color-by-number artwork from any photo
Upload a photo and Mosaci automatically assigns a number to every cell matching a color key — ready to print and color.
No credit card · 5 free exports/month
What is color-by-number?
Color-by-number is an artistic technique where an image is divided into sections, each labeled with a number that corresponds to a specific color in a key. The artist fills each section with the matching color, gradually revealing the full picture. Originally a children's pastime, color-by-number has grown into a popular adult mindfulness activity and a best-selling category on Amazon KDP and Etsy. Mosaci automates the entire conversion process — turning any photo into a numbered mosaic grid with an automatic color key.
Why use Mosaci?
- Automatic color reduction — no manual palette selection needed
- Numbered cells with matching color key included
- Choose grid size and color count
- Export a single page or an entire book of pages
- PDFs sized for Amazon KDP publishing
- Works with any photo: portraits, pets, landscapes, patterns
- Free plan with 5 exports per month
- Browser-based — no install required
How it works
- Step 1
Upload any photo
Drag and drop a JPG, PNG, or WebP image. Works best with photos that have clear subjects and reasonable contrast.
- Step 2
Mosaci assigns numbers
The tool reduces your image to a clean color palette and assigns a unique number to each color zone across the mosaic grid.
- Step 3
Export and print
Download a PDF with the numbered grid and color key. Print at home or upload directly to Amazon KDP as a coloring book interior.
Who is this for?
KDP coloring book authors
Produce entire color-by-number book interiors from photo collections. Each export is print-ready with correct KDP dimensions.
Etsy digital product sellers
Create custom color-by-number pages from customer photos for personalized gifts — birthdays, weddings, pet portraits.
Teachers and activity leaders
Generate color-by-number worksheets from any image for classroom art activities or after-school programs.
Adult mindfulness crafters
Turn favorite photos into relaxing color-by-number pages for personal use or gifts.
Frequently asked questions
What is a color-by-number generator?
A color-by-number generator converts a photo into a grid of numbered cells. Each number corresponds to a specific color, so the artist colors each cell according to its number to recreate the original image.
Can I create a color-by-number from my own photo?
Yes. Upload any JPG, PNG, or WebP photo to Mosaci and it automatically generates a custom color-by-number page with a matching color key.
How many colors does Mosaci use?
Mosaci reduces the image to a palette of your choosing — typically 8 to 24 colors — to create a clear, printable layout.
Is the color-by-number generator free?
Yes. Mosaci offers 5 free exports per month. Paid plans unlock unlimited exports.
Related tools & guides
Ready to create your first page?
Join thousands of KDP creators, Etsy sellers, and hobbyists turning photos into print-ready coloring pages with Mosaci.
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