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Head-to-head · PDF Compression Software

PDFOptim vs FS PDF Compressor

  • Updated Oct 2026
  • Both researched from official sources
  • 3 checks side by side
Higher score PDFOptim #3 in PDF Compression Software 9.0/10 Free plan Free plan✓ 2 of 3 features Visit PDFOptim
FS PDF Compressor #4 in PDF Compression Software 8.9/10 Free plan Free plan✓ 2 of 3 features Visit GitHub

PDFOptim leads on 0 checks, FS PDF Compressor on 0, and 3 are even. Who comes out ahead on the 3 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scorePDFOptim · 9.0/10
  • Free planboth

PDFOptim scores higher on our rubric for pdf compression software: 9.0 against 8.9 out of 10; our editors rank them #3 and #4.

PDFOptim is the better fit for users wanting previews and cross-platform workflows. FS PDF Compressor is the better fit for privacy-focused users wanting free desktop compression.

  • PDFOptim fits best

    Users wanting previews and cross-platform workflows

  • FS PDF Compressor fits best

    Privacy-focused users wanting free desktop compression

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Side by side

Feature PDFOptim 9.0/10 Visit ↗ FS PDF Compressor 8.9/10 Visit ↗
At a glance
Editor score 9.0 8.9
Ranking #3 in PDF Compression Software #4 in PDF Compression Software
Best for Users wanting previews and cross-platform workflows Privacy-focused users wanting free desktop compression
Pricing model Free plan + paid Free
Starting price $4.99/mo Free
Free plan ✓ ✓
Free trial — —
Deployment Cloud, Desktop, Mobile Desktop
Platforms Web, macOS, iOS, Windows macOS, Windows, Linux
Integrations 1 integrations 4 integrations
Features PDFOptim 2/3 · FS PDF Compressor 2/3
Batch compression ✓ ✓
Offline desktop app ✓ ✓
API access Not checked yet Not checked yet
Specs
Compression modes Balanced Balanced
Maximum file size 25 MB Not checked yet
Supported platforms web, macos, ios, windows macos, windows, linux
Our review
Pros
  • Side-by-side previews help compare compression quality before saving.
  • Presets cover Web, Standard, Print, and Custom compression needs.
  • Native batch processing supports scanned and vector PDF optimization.
  • Local processing without uploads, accounts, analytics, or telemetry
  • Batch compression for multiple PDFs and folders
  • Native integrations across macOS, Windows, and Linux file managers
Cons
  • The Free plan allows only 3 operations per day.
  • Free files are limited to 25 MB; paid plans allow up to 200 MB.
  • Apple Shortcuts is the only listed integration.
  • Desktop-only workflow across macOS, Windows, and Linux
  • Three profiles provide less granular quality control
  • Compression depends on the bundled Ghostscript runtime
Our verdict

PDFOptim is a PDF compression product with browser-based tools and native applications for macOS, iOS, and Windows. It is designed for users who need to reduce PDF sizes across devices, compare output quality before saving, or process…

Read the review →

FS PDF Compressor is a free, open-source desktop utility for reducing PDF file sizes locally. It is suited to privacy-focused users, individuals handling documents on their own computers, and teams that need batch compression without…

Read the review →
  1. PDFOptimPDF Compression Software 9.0Free plan
  2. FS PDF CompressorPDF Compression Software 8.9Free plan

Strengths and trade-offs

  • PDFOptim — where it wins

    • Side-by-side previews help compare compression quality before saving.
    • Presets cover Web, Standard, Print, and Custom compression needs.
    • Native batch processing supports scanned and vector PDF optimization.

    Where it doesn't

    • The Free plan allows only 3 operations per day.
    • Free files are limited to 25 MB; paid plans allow up to 200 MB.
    • Apple Shortcuts is the only listed integration.

  • FS PDF Compressor — where it wins

    • Local processing without uploads, accounts, analytics, or telemetry
    • Batch compression for multiple PDFs and folders
    • Native integrations across macOS, Windows, and Linux file managers

    Where it doesn't

    • Desktop-only workflow across macOS, Windows, and Linux
    • Three profiles provide less granular quality control
    • Compression depends on the bundled Ghostscript runtime
  • PDFOptim9.0/10 · Free plan

    A flexible PDF compressor with previews, batch processing, and cross-platform coverage.

    Visit PDFOptimFull verdict →
  • FS PDF Compressor8.9/10 · Free plan

    A privacy-focused, open-source desktop compressor with batch workflows and three quality profiles.

    Visit GitHubFull verdict →

More comparisons

All PDF compression software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update