Deskew PDF
Automatically straighten scanned or tilted PDF pages. Fix skewed documents with precision angle detection.
Upload Scanned PDF Files
About This Tool
Deskew PDF automatically detects and corrects tilted or skewed pages in your PDF documents using advanced projection profile variance analysis. This is essential for scanned documents that were fed into the scanner at an angle.
The tool analyzes the text and content alignment at different angles to find the optimal rotation, then applies the correction. You can adjust the sensitivity threshold (1-30) and DPI settings (72-300) for optimal results.
All processing happens locally in your browser using WebAssembly technology, ensuring your documents remain private and secure.
How to Use
Upload Your PDF
Drag and drop your scanned PDF file or click to select.
Configure Settings
Adjust threshold sensitivity and DPI if needed for better detection.
Process and Download
Click Deskew to straighten pages and download the corrected PDF.
Use Cases
Scanned Documents
Fix pages that were scanned at an angle from document feeders.
Mobile Scans
Correct tilted photos of documents taken with smartphones.
Archive Restoration
Straighten old scanned archives for better readability.
Frequently Asked Questions
How accurate is the angle detection?
The tool uses projection profile variance analysis to detect skew angles up to ±10 degrees with high accuracy. It automatically skips pages with angles less than 0.3 degrees.
Will text quality be affected?
For rotations at multiples of 90 degrees, no quality loss occurs. For other angles, the tool rounds to the nearest degree and maintains good quality.
Can I deskew specific pages only?
The tool analyzes all pages but only corrects those with detected skew above the sensitivity threshold. Pages with minimal skew are left unchanged.
What is the sensitivity threshold?
Values 1-10 correct obvious tilts only, 11-20 detect moderate skew, and 21-30 catch subtle angles. Default is 10 for balanced detection.
How long does processing take?
Processing time depends on file size and DPI. 150 DPI (default) provides good balance between speed and accuracy. Higher DPI is more accurate but slower.