How-to Guide 2 min read

How to Compress Scanned Documents Online

Scanner apps and desktop scanners save documents as large PNG or TIFF files — often 2–10MB per page. For email attachments, government portal submissions, and cloud storage, you need them under 1–2MB. This guide compresses scanned documents to the smallest possible size while keeping all text legible and barcodes scannable.

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By ImgToolkit Team · Updated May 2026 · 2 min read · Processed in your browser
PNGJPGWebPGIFBMP

Quick Answer

Scanner apps and desktop scanners save documents as large PNG or TIFF files — often 2–10MB per page. For email attachments, government portal submissions, and cloud storage, you need them under 1–2MB.

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Compress Scanned Document

Step-by-Step Guide

5 steps · takes under 1 minute

1

Identify the source format

Mobile scanner apps (Adobe Scan, Microsoft Lens) typically save as PDF (with embedded JPG). Flatbed scanners save as TIFF, BMP, or PNG. For PDF scans: extract the embedded images. For TIFF/PNG/BMP: go directly to the compressor.

2

Convert TIFF or BMP to JPG or PNG first

TIFF and BMP are uncompressed formats — convert to JPG or PNG using the Convert to JPG tool. A 10MB TIFF document page typically becomes 500KB–1.5MB as JPG at 85% quality.

3

Compress at 75% quality for text documents

Text documents with black-and-white content can be compressed more aggressively than photos. At 75%, text remains crisp and legible. At 70%, start checking that fine print and handwriting are still readable. Avoid dropping below 70% for text documents.

4

Check legibility before submitting

Zoom to 100% and read a sample of the text. Check that barcodes, QR codes, and signatures are still clear. If any element is hard to read, increase quality to 80%.

5

Verify file size meets submission requirements

Government portals typically require scanned documents under 500KB–2MB per page. Email attachments: under 10MB total. Court documents: often 300KB–1MB per page. Confirm the specific requirement before finalising.

Before vs After Compression

Typical result on a 1080×1080px product photo

Before 4.2 MB
📷 Original PNG
After 820 KB
🗜️ −80% smaller
Before: 4.2 MB — slow to load, rejected by email
After: 820 KB — fast loading, visually identical
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Pro tip

Use 75–85% quality for web images — you get 60–80% smaller files with no visible difference at normal screen sizes.

Format & File Size Comparison

Same 1080×1080px photo processed four ways

FormatQualityFile SizeNotes
PNG (original) Perfect 4.2 MB No compression — too large for web
Compressed PNG Visually identical 1.1 MB −74% — transparency preserved
JPG (85% quality) Excellent 310 KB −93% · Best for photos
WebP (85%)BEST Excellent 205 KB −95% · Recommended for web

Based on a 1080×1080px photo. Results vary by image content and complexity.

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Frequently Asked Questions

4 questions answered

What compression quality is safe for scanned documents?

For black-and-white text documents: 70–75% JPG quality. Text remains legible; file size reduces by 60–75% from the uncompressed scan. For colour documents with signatures: 80%. For documents with fine print or very small fonts: 80–85%. Always visually verify text is legible after compression.

Will compressing a scan affect signatures and stamps?

At 75%+ quality, official signatures, rubber stamps, and embossed seals remain visually clear. Some automated signature verification systems are sensitive to compression artefacts — for legally critical documents (court filings, notarised forms), check whether the receiving institution has specific format and quality requirements.

Can I compress a scanned document without making text blurry?

Yes — JPG at 75% quality compresses document size by 60–75% while keeping all standard-sized text (8pt+) clearly legible. Text documents compress differently from photos — the high-contrast nature of black text on white paper compresses very efficiently at this quality level.

What is the best app to scan documents at a small file size?

Microsoft Lens (iOS/Android): outputs compact PDFs and JPGs. Adobe Scan: similar output quality, integrates with Adobe. CamScanner: includes compression options. For lowest file size: Microsoft Lens with 'Document' mode at medium quality. All three produce scans at 200–300KB per page — much smaller than flatbed scanner defaults.

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Compress Scanned Document

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