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Compress PDF

Local

Reduce PDF file size in your browser

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Compress PDF
Local
Processing limits
  • Rendered PDFs: up to 500 pages, 8,192 px per side, 32 MP per page, 100 MP in total, and 250 MiB of output.
  • These are memory budgets, not upload limits — a large file is only ever read by your own browser.
Tool Details
Input formatsPDF
Output formatPDF
Max file size100 MB
Max files1
PDF render limits

500 pages · 8,192 px/side · 32 MP/page · 100 MP total · 250 MiB output

ProcessingLocal
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Privacy First

Your files are processed entirely in your browser. Nothing is uploaded to any server.

How do I make a PDF file smaller?

Load the PDF, pick a compression mode, and run it. Safe optimization rewrites the file structure and leaves your pages untouched, so text stays selectable. Balanced and maximum instead rebuild every page as an image, which shrinks image-heavy documents far more but discards the text layer. Compression runs in your browser, so nothing is uploaded.

About the Compress PDF

Compress PDF files locally with either safe structure optimization or page rasterization for image-heavy documents. Balanced and maximum compression modes can reduce quality and remove selectable text.

  • Reduce large PDFs before emailing, uploading to portals, or storing archives.
  • Use safe optimization when you want to preserve selectable text and original page content.
  • Use balanced or maximum compression for image-heavy PDFs where smaller size matters more than perfect sharpness.

How to use the Compress PDF tool

  1. 1

    Upload PDF file

    Select PDF file from your device or drag file into the upload area.

  2. 2

    Choose settings

    Choose settings such as Compression Mode, Remove document metadata before processing.

  3. 3

    Compress PDF

    Run the Compress PDF tool to create the PDF output.

  4. 4

    Download the result

    Download the finished file. The original file stays on your device and is not uploaded.

What is the difference between the three compression modes?

Safe optimization re-saves the document with a more compact internal structure and, if you leave the option enabled, clears the metadata fields. Your page content is not touched, so text stays selectable and searchable — but the saving is modest and depends entirely on how wastefully the original was written. Balanced and maximum take a different approach: each page is rendered to an image and rebuilt from it, at a moderate resolution and quality for balanced and a noticeably lower one for maximum.

What do you lose with balanced or maximum compression?

The text layer, and with it searchability, copy-and-paste, links, form fields, and the accessibility structure screen readers depend on. The pages will look like the original at normal viewing size, but they are pictures of pages now, and small type softens as you zoom. That is an acceptable trade for a scanned brochure you need under an email limit; it is the wrong trade for a contract someone needs to search, or for any document that has to remain accessible.

Why did compression barely change the file size?

Because the size was not where you assumed. A PDF that is large due to high-resolution photographs shrinks dramatically under the rasterising modes. A PDF that is large due to embedded fonts, vector artwork, or a huge amount of text does not, because there is little image data to recompress and the text is already efficiently stored. If safe mode achieves almost nothing and the pages are mostly text, the file is probably already close to as small as it can honestly get.

Are my files uploaded when compressing a PDF?

No. Compression is the tool people most often reach for under time pressure — a portal rejected an upload, an email bounced — and that is exactly when a document gets pasted into the first website available. Here the file is read, rewritten or re-rendered, and saved entirely within your browser, so an oversized tax return or medical record does not become a copy on someone else’s disk.

How to do this offline, on the command line

Ghostscript is what most online compressors run server-side. Running it yourself removes the upload and gives you the presets directly.

Ghostscript

macOS: brew install ghostscript · Debian/Ubuntu: apt install ghostscript

gs -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -dNOPAUSE -dBATCH -sOutputFile=small.pdf big.pdf

Presets from smallest to largest: /screen, /ebook, /printer, /prepress. Ghostscript rewrites the whole file, so check the output before discarding the original.

qpdf

macOS: brew install qpdf · Debian/Ubuntu: apt install qpdf

qpdf --object-streams=generate --compress-streams=y big.pdf smaller.pdf

Lossless — it recompresses structure only and never touches image data, so the saving is smaller but nothing degrades.

Frequently Asked Questions

Will compression change PDF quality?
Safe optimization preserves the original page content. Balanced and maximum modes rasterize pages as images, which can make files smaller but may reduce sharpness and remove selectable text.
How can I compress a PDF without losing selectable text?
Choose Safe optimization. It removes unnecessary structure and metadata where possible without turning pages into flat images.
Are files uploaded for compression?
No. PDFBase compresses files locally in your browser, so your PDF never leaves your device.

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