How to Compress Scanned PDF Files
Scanned PDFs are notoriously large. Reduce scanned document file size by 50-70% while keeping text perfectly readable. Free and instant.
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Upload your scanned document and reduce its file size in seconds.
Compress Scanned PDF Free →Why Are Scanned PDFs So Large?
Unlike regular PDFs that store text as data (very small), scanned PDFs store every page as a full image. Here's how sizes compare:
💡 Our PDF compressor can reduce these scanned files by 50-70% — turning a 50MB scan into a 15MB file, or a 10MB scan into 3MB.
Best Compression Mode for Scanned PDFs
✅ Strong Mode (Recommended)
Best for most scanned documents. Achieves 50-70% reduction while maintaining text readability. Use this for receipts, contracts, and everyday scans.
Balanced Mode
Use when image quality matters (e.g., scanned photos, architectural drawings). Provides 30-40% reduction with excellent visual quality.
Target Size Mode
Use when you need an exact file size (e.g., under 1MB for uploads). Set your target percentage and let the compressor optimize.
Light Mode
Minimal compression (10-15%). Use when you need maximum quality preservation for high-value original scans like legal documents or certified copies.
How to Compress a Scanned PDF: Step by Step
1. Upload Your Scanned Document
Go to our PDF compressor and upload your scanned PDF. Our tool automatically detects image-heavy PDFs and optimizes accordingly.
2. Choose Strong Mode
For scanned documents, Strong mode provides the best size-to-quality ratio. It aggressively compresses the embedded images while keeping text readable.
3. Download Your Compressed Scan
Review the compression results — you'll see the exact reduction percentage and new file size. Download and use your compressed scan for email, uploads, or storage.
Types of Scanned PDFs We Compress
Contracts & Legal Docs
Signed agreements, notarized documents
Receipts & Invoices
Expense reports, tax documents
Medical Records
Lab results, prescriptions, reports
Certificates & Diplomas
Academic records, certifications
Property Documents
Deeds, titles, appraisals
Book & Article Scans
Research papers, textbook chapters
Compress Scanned PDF — FAQ
Why are scanned PDFs so large?
Scanned PDFs contain full-page images instead of text data. A single scanned page at 300 DPI can be 5-10MB because the scanner captures everything as a high-resolution image. A 10-page scanned document can easily reach 50-100MB.
How much can I compress a scanned PDF?
Scanned PDFs typically compress the best of any PDF type. Expect 50-70% reduction with Strong mode. A 20MB scanned document can often be compressed to 5-8MB while maintaining readability. Some heavily scanned PDFs can see up to 80% reduction.
Will compressing a scanned PDF affect text readability?
With Balanced mode, text remains perfectly readable. Strong mode may slightly soften image quality but text is still clear and legible. For critical documents like contracts, use Balanced mode. For archival or reference copies, Strong mode is fine.
Can I compress a multi-page scanned document?
Absolutely! Our compressor handles multi-page scanned PDFs with ease. Each page's images are individually optimized. The free tier supports up to 10MB (enough for several scanned pages), while Pro handles up to 100MB (dozens of scanned pages).
Does compression affect OCR (searchable text) in scanned PDFs?
If your scanned PDF has an OCR text layer, compression preserves the searchable text. Only the underlying images are compressed. You can still search, select, and copy text after compression.
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