Which compression quality level should I choose?

Screen (72 DPI) is ideal for web sharing and email — smallest file size. eBook (150 DPI) balances size and readability. Printer (300 DPI) suits desktop printing. Prepress (300 DPI) retains maximum colour accuracy for professional printing workflows. Custom DPI lets you set any resolution from 50 to 600 DPI for precise control.

How much can PDF compression reduce file size?

Image-heavy PDFs can see reductions of 50–90%. Text-only PDFs with minimal graphics typically see smaller reductions, as the text itself is already compact vector data. Enabling stream recompression and metadata stripping adds additional savings on top of image compression.

Does compression affect text or font quality?

No. PDF text and fonts are vector-based and are unaffected by DPI compression settings. Only embedded raster images are resampled during compression.

What does "Strip Metadata" do?

Strips the PDF Info dictionary (author, title, creator, creation date, etc.). Useful for privacy or reducing file size when sharing documents publicly.

What does "Web-Optimized" (linearize) mean?

Linearization restructures the PDF so the first page can be displayed before the entire file downloads — ideal for large PDFs served over the web. It does not reduce file size but improves load-time user experience.

What does "Recompress Streams" do?

Re-encodes all internal PDF data streams using maximum-level Flate (Deflate) compression via qpdf. This squeezes additional space from the structural parts of the PDF that Ghostscript may not have fully compressed, typically saving 2–10% on top of image resampling.

Compress PDF — Free Online PDF Compressor

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About Compress PDF

Reduces PDF file size by downsampling images and recompressing content. Five quality presets — Screen (72 dpi), eBook (150 dpi), Printer (300 dpi), Prepress (300 dpi with full colour), and Custom (50–600 dpi). Optional extras: strip document metadata, linearise for fast web view, and recompress content streams via qpdf. After conversion the result panel shows the original size vs. the compressed size. Processing is handled server-side by Ghostscript and qpdf.

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When does compression help?

Compression works by downsampling embedded raster images to the target DPI. Image-heavy PDFs (scans, photos, presentations) typically see 40–90% size reduction. Text and vector PDFs (spreadsheets, reports, diagrams) may see little or no reduction — text and vector paths are already stored as compact data that DPI settings cannot shrink. If your PDF returns at the same size, it either has no high-resolution images or its images are already at or below the target DPI. In that case, enabling Recompress Streams may still yield a small additional saving.

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Drop a PDF file here or click to browse

Single PDF file — up to 200 MB

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Screen (72 dpi)

Lowest quality, smallest file. Best for on-screen reading only — not suitable for printing.

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eBook (150 dpi)

Good quality for email, sharing, and digital reading. Recommended for most use cases.

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Printer (300 dpi)

High quality output suitable for desktop printing. Larger file size than eBook.

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Prepress (300 dpi)

Maximum quality with colour profiles preserved. For professional print production.

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Custom DPI

Set any resolution from 50–600 dpi. Combine with recompress streams for maximum control over size vs quality.

Page 1 — Before / After

Original Compressed

Up to 90% file size reduction on image-heavy PDFs
Five quality modes — screen, eBook, printer, prepress, custom DPI
Custom DPI slider from 50–600 for precise image resampling
Strip metadata — removes author, title, and document info for privacy
Linearize — web-optimized output for instant first-page browser display
Recompress streams — maximum Flate compression via qpdf for extra savings
Preserves text layer, fonts, and selectable content
Server-side processing — nothing stored after download