PDF Compression Made Text Blurry? Here's How to Fix It

You compressed your PDF to meet an upload limit, but now the text looks like it was printed on a potato. Don’t worry — this is fixable.

Here’s how to get readable text while still hitting your size target.

Why Text Gets Blurry

The Compression Trade-off

PDF compression reduces file size by:

1. Lowering image resolution (DPI)
2. Increasing JPEG compression
3. Reducing color depth

When these settings are too aggressive, text becomes unreadable.

Common Causes of Blurry Text

1. DPI too low: Below 150 DPI, text starts to blur
2. Over-compression: Extreme size reduction damages quality
3. Wrong mode: Black & white mode on grayscale documents
4. Poor source: Original scan was low quality
5. Multiple compressions: Compressing an already-compressed file

Quick Fixes

Fix 1: Increase Target Size

The simplest fix — allow a larger output file.

Before: Target 5MB → Blurry result After: Target 10MB → Clear text

If your limit allows, increase target by 20-50%.

Fix 2: Switch to Grayscale

If you’re using black & white mode, switch to grayscale.

Black & white: Only pure black and white pixels (harsh on text) Grayscale: 256 shades of gray (smoother text edges)

Grayscale files are slightly larger but much more readable.

Fix 3: Increase DPI

DPI (dots per inch) directly affects text clarity.

DPI	Text Quality	File Size
72	Very blurry	Smallest
100	Blurry	Small
150	Acceptable	Medium
200	Good	Medium-Large
300	Excellent	Large

Recommendation: Use 200 DPI for most documents.

Fix 4: Start from Original

If you’ve compressed multiple times, go back to the original:

1. Find your original scan or PDF
2. Compress once with correct settings
3. Never re-compress the output

Each compression cycle degrades quality.

Detailed Troubleshooting

Problem: Small Text is Unreadable

Symptoms: Body text is okay, but footnotes, captions, or fine print are blurry.

Solutions:

1. Increase DPI to 250
2. Increase target size by 30%
3. Consider splitting document (compress main text less, appendices more)

Problem: Text Has Jagged Edges

Symptoms: Letters look pixelated or stair-stepped.

Solutions:

1. Switch from black & white to grayscale
2. Increase DPI
3. Check if original was scanned in black & white

Problem: Text Has Artifacts

Symptoms: Blocks, smearing, or “ringing” around letters.

Solutions:

1. Reduce compression level (increase target size)
2. Use a different compression tool
3. Check if original PDF was already heavily compressed

Problem: Numbers Are Confusing

Symptoms: Can’t tell 0 from O, 1 from l, 5 from S.

Solutions:

1. This is critical — increase quality significantly
2. Use at least 200 DPI
3. Verify output before submitting

Settings Guide by Document Type

Text-Heavy Documents (Reports, Contracts)

Mode: Grayscale
DPI: 200
Target: 70-80% of original size

Forms with Checkboxes

Mode: Grayscale (not black & white)
DPI: 200
Target: 60-70% of original size

Documents with Fine Print

Mode: Grayscale
DPI: 250
Target: 80-90% of original size

Mixed Text and Photos

Mode: Color
DPI: 200
Target: 50-70% of original size

Prevention: Getting It Right First Time

Before Scanning

• Scan at 200-300 DPI (not 72 or 600)
• Use grayscale for text documents
• Ensure good lighting and alignment
• Clean the scanner glass

Before Compressing

• Know your size limit
• Start with moderate settings
• Plan to verify output

Compression Settings

For readable text, never go below:

• DPI: 150 (200 preferred)
• Target: 50% of original (for scanned docs)
• Mode: Grayscale for text

Quality Verification Process

After compression, always check:

Step 1: Open at 100% Zoom

Text should be clearly readable at normal viewing size.

Step 2: Check at 150% Zoom

Simulates viewing on high-DPI screens or slight enlargement.

Step 3: Spot-Check Problem Areas

• Footnotes and captions
• Table data
• Numbers and codes
• Signatures

Step 4: Print Test (If Critical)

For important documents, print a page to verify quality.

When to Accept Some Blur

Sometimes you can’t avoid all quality loss:

Acceptable Blur

• Background images in figures
• Decorative elements
• Non-critical appendices
• Documents for temporary use

Unacceptable Blur

• Primary text content
• Numbers and data
• Legal signatures
• Medical information
• Anything that will be referenced

Tool-Specific Tips

SecureCompress

• Use “Grayscale” mode for text documents
• Set DPI to 200 for balanced quality
• If text is blurry, increase target by 20%

Adobe Acrobat

• Use “High Quality” preset as starting point
• Adjust image settings individually if needed
• Check “Optimize for Fast Web View”

Preview (Mac)

• “Reduce File Size” often over-compresses
• No control over settings
• Use only for non-critical documents

Real-World Examples

Example 1: Resume Too Blurry

Problem: Compressed resume is unreadable Original settings: 100 DPI, 2MB target Fixed settings: 200 DPI, 5MB target Result: Clear, professional-looking resume

Example 2: Tax Form Numbers Unclear

Problem: Can’t distinguish 0 from 8 Original settings: Black & white, 150 DPI Fixed settings: Grayscale, 200 DPI Result: All numbers clearly readable

Example 3: Contract Fine Print Gone

Problem: Terms and conditions unreadable Original settings: 150 DPI, aggressive compression Fixed settings: 200 DPI, 80% of original size Result: All text readable, file still under limit

Summary

To fix blurry text after compression:

1. Increase target size — the easiest fix
2. Use grayscale — not black & white
3. Set 200 DPI minimum — for readable text
4. Start from original — don’t re-compress
5. Verify before submitting — check at 150% zoom

Quality and size are a trade-off. Find the balance that keeps your text readable while meeting your size requirements.

Download SecureCompress — compression that keeps text readable.