Auto-Crop PDF
Automatically detect content boundaries in scanned PDFs and remove scanner borders, extra margins, and whitespace for cleaner documents.
100% Private
Instant Processing
Browser-Based
Features
Smart content boundary detection using computer vision
Removes scanner borders and black edges automatically
Adjustable margin padding around detected content
Processes all pages in multi-page PDFs
Preserves content quality with high-resolution rendering
Falls back to original page if no content boundaries detected
No AI credits required
Powered by PDFSub Engine
Files encrypted during transfer, auto-deleted after processing
How It Looks
Scanned Page
Cropped Result
How It Works
1
Upload a scanned PDF with scanner borders or extra margins
2
The tool analyzes each page to detect content boundaries
3
Pages are cropped to the content area with optional margin padding
4
Download the trimmed PDF with clean edges
Common Use Cases
Removing black scanner borders from scanned documents
Trimming excessive margins from scanned book pages
Cleaning up misaligned scan margins across multiple pages
Standardizing page sizes in a batch of scanned documents
Preparing scanned archives for digital storage
Removing whitespace borders before printing
Frequently Asked Questions
How does content detection work?
Each page is rendered as an image and converted to binary (black/white). The tool finds the bounding rectangle of all non-white content, then crops to that area with optional margin padding.
Can I adjust the margin around content?
Yes. Set the margin value (0-100 pixels) to control how much padding is kept around the detected content. The default is 10 pixels.
Does it handle multi-page PDFs?
Yes. Every page is analyzed and cropped individually. Each page may end up with different dimensions depending on its content.
What if no content is detected on a page?
If a page appears to be blank or content cannot be detected, the original page is kept unchanged.
What file size limit applies?
The same file size limit as your subscription plan allows. PDFs can have up to 50 pages.
Does this use AI credits?
No. Auto-Crop uses computer vision processing, not AI. It does not consume any AI credits.
Is my file processed securely?
Your files are processed securely by the PDFSub Engine - an isolated server with no internet access. Files are encrypted during transfer and auto-deleted after processing.