You can straighten scanned PDF online by deskewing crooked pages, rotating tilted scans, and saving them neatly with Smallpdf.
Scanned PDFs often come out crooked because the paper wasn’t perfectly aligned on the scanner. Even a small tilt makes reading harder, especially for long documents or legal files.
Instead of rescanning, you can straighten PDF pages directly online.
How to Straighten a Scanned PDF: Step-by-Step Guide
With Smallpdf, you can align your text and improve readability in seconds. Here’s how:
Step 1: Open the PDF
Go to Edit PDF.
Step 2: Upload Your Scanned File
Drag and drop your scanned PDF into the editor. You can also import from Google Drive, Dropbox, or OneDrive.
Step 3: Rotate or Align the Pages
Use the rotate option to deskew tilted pages. If your file has multiple pages, check each one to ensure they are straightened.
You can find it in the left corner, as you can see below:
How to Straighten a Scanned PDF
Step 4: Save the Updated PDF
Click Export to download your aligned file or save it back to your cloud storage. If you prefer editing in Word after straightening, you can also convert the document from PDF to Word.
How to Deskew PDF Pages on Mobile Devices
Crooked PDFs aren’t just a desktop issue — mobile scanning apps often tilt pages too. With Smallpdf, you can straighten PDF pages from your phone’s browser.
Upload your file, rotate it into alignment, and save. You don’t need extra apps, but if you prefer working on an app, you can download the Smallpdf app for better navigation.
For reading the updated version comfortably, try Smallpdf’s PDF Reader, which gives you a clean viewing experience once the pages are corrected.
Why Do Scanned PDFs Look Crooked?
Even the best scanners can produce skewed files. Common reasons include:
- The document wasn’t placed flat on the scanner glass.
- The feeder tray pulled the page at a slight angle.
- Low-resolution scans amplified small tilts.
When this happens, lines of text no longer appear straight, making it harder to review or annotate. Straightening the file ensures better readability, especially if you plan to edit or share the PDF.
Alternative Methods to Straighten PDF Pages
While Edit PDF is the easiest option, there are other approaches you can try.
1. Convert and Edit in Word
You can convert your file with Smallpdf’s PDF to Word, then adjust alignment in Word before exporting it back to PDF. This method is helpful if you’re already planning to edit text.
2. Unlock and Edit Secured PDFs
If the scanned PDF is restricted, you may need to unlock it first. Use Smallpdf’s Unlock PDF to remove restrictions before making adjustments.
3. Rotate Pages in a Reader
Sometimes, all you need is a simple rotation. With Smallpdf’s PDF Reader, you can view, rotate, and re-save the document at the correct angle.
These alternatives show that learning how to straighten a PDF doesn’t always mean rescanning — online editing and conversion give you flexible options.
FAQs
1. How can I straighten a scanned PDF without rescanning?
Upload it to Smallpdf’s Edit PDF, rotate the crooked pages into place, and save the updated file.
2. Can I straighten scanned PDFs on my phone?
Yes. Open Edit PDF in your mobile browser, upload the file, rotate the pages, and export the straightened version.
3. What’s the difference between rotating and straightening a PDF?
Rotating flips a page 90 or 180 degrees. Straightening (deskewing) fixes small tilts, aligning text lines horizontally for easier reading.
4. Can I straighten just one page in a multi-page PDF?
Yes. In Edit PDF, you can select the specific page you want to adjust and rotate only that one.
5. Why do scanned PDFs often look tilted or skewed?
Paper alignment issues, feeder errors, or low-resolution scanning can tilt pages. Straightening fixes this after scanning.
6. What are the best free ways to straighten scanned PDFs online?
By using Smallpdf. Just upload your file, align the pages, and download the file. Free, quick, and easy to use.
