Free Deskew Tool
Deskew a scanned PDF online free
Automatically straighten scanned pages that came out slightly crooked. Use the tool below, then download the corrected file.
Browser-based auto-straighten
Open a scanned PDF and automatically straighten pages that were scanned slightly crooked. Works best on text-heavy pages — it estimates the skew angle from the horizontal lines of text.
Your files are handled safely
✔ Processing happens in your browser
✔ Your file is never uploaded to a server
✔ Your files are not stored or saved anywhere
✔ No account or sign-up required
Why Use It
Common reasons to straighten a scan
Fix crooked phone scans
Straighten pages photographed at a slight angle instead of re-scanning them.
Automatic angle detection
The tool estimates the skew angle from the page's own text lines — no manual rotation slider needed.
Cleaner archives
Straightened pages are easier to read and look more professional once shared.
How It Works
Simple 3-step workflow
1. Choose your scanned PDF
Choose the PDF file with crooked pages.
2. Run auto-straighten
The tool detects and corrects the skew angle on each page.
3. Download the straightened PDF
Save the corrected file.
Honest Limits
Best for text-heavy scans
Automatic deskewing estimates the angle from lines of text — it works best on typical documents and may be less accurate on pages that are mostly images or very sparse text.
FAQ
Deskew questions
How does the tool know which way to straighten a page?
It analyzes the horizontal lines formed by text on the page and finds the rotation angle that makes those lines sharpest — the standard approach for automatic deskewing of text documents.
Does this work on photos or pages without much text?
It works best on text-heavy scans. Pages that are mostly images or have very little text may not be detected accurately.
Will this reduce image quality?
Each page is re-rendered as an image to apply the rotation, similar to Compress PDF or Grayscale PDF, so there's a small amount of re-encoding involved.
Is my file uploaded to a server?
No. Detection and straightening both happen entirely in your browser. Nothing is uploaded or stored.