Sudoku4John

Enter numbers above to validate

Input Methods

Developer Integration

Performance Benchmarks

Basic
—

Loops through each row, column, and box to check for duplicates

Bitwise
—

Uses bit manipulation to track seen numbers - each bit represents a digit 1-9

Ultra-Fast
Active
—

Combines all checks into one operation and exits early on first error

Run benchmarks to compare algorithm performance

API Reference

POST/api/validate
Validate a single sudoku puzzle

Examples

curl
curl -X POST https://sudoku4john.com/api/validate \  -H "Content-Type: application/json" \  -d '{"grid": "534678912672195348198342567859761423426853791713924856961537284287419635345286179"}'

Try it

POST/api/batch
Validate multiple sudoku puzzles (up to 1000)

Examples

JavaScriptbatch.js
const response = await fetch('https://sudoku4john.com/api/batch', {  method: 'POST',  headers: { 'Content-Type': 'application/json' },  body: JSON.stringify({    grids: [      '534678912672195348198342567859761423426853791713924856961537284287419635345286179',      '123456789578139624496872153952381467641297835387564291719623548864915372235748916'    ]  })});const result = await response.json();console.log(`${result.successCount} valid, ${result.failureCount} invalid`);

Try it

POST/api/ocr
Extract sudoku puzzle from image using AI

Examples

GNU Bashupload.sh
curl -X POST https://sudoku4john.com/api/ocr \  -F "image=@sudoku-puzzle.png"

Try it

Upload an image containing a sudoku puzzle