Compress PDF Free Online

Compress PDF
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Drop a PDF below. CrunchBox shrinks the images inside it and rebuilds the file smaller. All processing happens in your browser.

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    What PDF compression does
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    Most of a large PDF is its images: scanned pages, photos, screenshots. CrunchBox redraws each image as a JPG at a lower quality and, when it is very large, with fewer pixels, then puts it back in place. It also rebuilds the file and leaves out anything no page uses.

    Text, fonts, and drawings are not touched. Text stays sharp, and you can still select and search it. A PDF that is large because of its fonts or drawings will not shrink much, and the tool says so.

    Everything else in the file is kept as it was: fillable form fields and what you typed in them, bookmarks, links, attachments, and the tags screen readers use.

    How it works
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    1. Drop your PDF into the box above. It is compressed right away at the Balanced level
    2. For a smaller file or a gentler touch, pick another level and click Compress again
    3. To hit a limit, type it in Max file size. CrunchBox uses the gentlest setting that fits
    4. Download the compressed PDF
    • Light: JPG quality 85%, images up to 3000 pixels on the long side
    • Balanced: quality 72%, up to 2200 pixels
    • Strong: quality 55%, up to 1500 pixels

    If the result would not be smaller, the tool tells you and offers no download.

    What it leaves alone
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    Some images are left exactly as they were, because changing them could change how the page looks:

    • CMYK images made for print
    • Transparency layers and masks
    • Black-and-white fax-style scans, which are already small
    • JPEG 2000 images
    • Icons and other small images

    The result shows how many images were recompressed and how many were left. Password-protected PDFs are refused: remove the protection first.

    Signed PDFs: changing any part of a digitally signed PDF makes its signature show as invalid. That is true of every compressor. The tool tells you when a PDF is signed, so you can keep the original.

    Common use cases
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    • Fitting a PDF under portal upload limits (government forms, court filings, benefits applications)
    • Emailing a report or presentation that's too large in its original form
    • Uploading to portals with strict file-size caps (job applications, university admissions, insurance claims)
    • Storing a book, manual, or report that's larger than it needs to be
    • Preparing PDFs for web download so visitors don't wait
    More PDF tools
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    Compress PDF to under 2 MB Fit a 2 MB upload limit Compress PDF for email Fit under Gmail, Outlook.com, Yahoo Mail, and iCloud Mail limits Merge PDF Combine multiple PDFs into one file Split PDF Pull out pages, or cut a PDF into separate files Rotate PDF Turn sideways or upside-down pages the right way Extract PDF Images Get every picture in a PDF as its own file JPG to PDF Combine images into a single PDF
    Privacy
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    Your PDF never leaves your device. Loading, rebuilding, and download all happen in your browser. CrunchBox has no server that could see the contents of your document: receipts, contracts, tax returns, medical records, whatever it is.

    This is why we run entirely in-browser: if we can't touch your files, we can't lose them, leak them, or profile them.