Compress Scanned PDF Online

1. Upload your scanned PDF (up to 50 MB).
2. Choose a compression level (Low, Medium, High, or Maximum).
3. Click 'Compress Scanned PDF' — takes 10-60 seconds depending on page count.
4. Download the smaller PDF.

Scanned PDFs are usually the largest — each page is a full-resolution image. Our compressor re-encodes those images at screen-appropriate quality, typically achieving 70-90% size reduction.

Scanned PDFs are image-based — every page is a full-resolution photo of a document. This makes them 5-20x larger than text-based PDFs of the same length. A 50-page scanned document can easily be 50 MB. Our compressor re-encodes the page images at screen-appropriate quality, typically achieving 70-90% size reduction while keeping text fully readable.

The compressor analyzes each scanned page, downsamples the embedded image to 150 DPI (or the target resolution for the chosen level), re-encodes it as efficient JPEG, and removes page-level metadata. Text remains fully legible. Output is PDF 1.7.

• Emailing large scanned documents (many clients cap at 25 MB).
• Uploading scanned PDFs to systems with size limits.
• Reducing cloud storage costs for scanned archives.
• Preparing scanned documents for web download.
• Meeting upload caps on job portals and forms.
• Shrinking a multi-page scanned book or manual.
• Optimizing receipts, invoices, and contracts.

At Medium (150 DPI), scanned text is fully legible on screens and most documents look identical to the original at normal viewing size. Higher compression levels reduce detail but keep text readable for typical documents.

• Best for scanned (image-based) PDFs — text PDFs use the general PDF compressor.
• Text is raster — not searchable without OCR.
• At Maximum level, fine detail may be lost.
• Handwritten documents may not compress as much as printed text.
• Encrypted PDFs must be unlocked first.
• Very small scanned PDFs (under 500 KB) may not benefit.

• Output PDF opens in every browser, reader, and OS.
• Text remains legible at Medium level.
• Editable in Adobe Acrobat, PDF-XChange.
• Printable at the downsample resolution.
• Accepted by every document management system.

• Medium (150 DPI) is the sweet spot for scanned PDFs — 70-85% smaller with no visible loss.
• For print-quality scans, use Low (200 DPI).
• For very large scans, Maximum can achieve 90%+ reduction.
• Text remains legible at every level except Maximum.
• Keep the original scan if the highest fidelity matters.

Text is barely readable after compression

Use a lower compression level (Low or Medium). Higher levels downsample more aggressively.

PDF is barely smaller

The PDF may already be optimized, or it may not be a true scanned PDF. Check if it's text-based.

Photographs lose detail

Photographs in scanned documents compress less efficiently. Use Low for photo-heavy scans.

• PDF Association — ISO 32000
• Ghostscript — PDF compression