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SPCXTools

Compress PDF

Shrink PDF files for email and uploads — losslessly, or with stronger compression for scans and image-heavy documents.

Runs locally — files never leave your device

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How to use Compress PDF

  1. 1Choose a PDF or drop it onto the page.
  2. 2Pick a level — Lossless keeps everything as it is, Recommended and Strong convert pages to compressed images for much smaller files.
  3. 3Click Compress PDF and wait while each page is processed on your device.
  4. 4Compare the old and new size, then click Download compressed PDF.

Make PDF files smaller

Email attachments are often limited to 10–25 MB, and many upload forms accept only a few megabytes. Scanned documents and PDFs full of photos easily exceed those limits. This PDF compressor reduces file size directly in your browser, with three levels to balance quality and size. Your documents are never uploaded, so it is safe for contracts, statements and personal records.

Compression levels explained

Lossless. The PDF is re-saved with a more compact internal structure (object streams), removing redundant data. Everything — text, fonts, links, form fields — stays exactly the same. This works best on PDFs that have been edited many times; for many files the saving is modest.

Recommended. Each page is rendered at 120 DPI and stored as a JPEG image in a new PDF. For scanned documents and image-heavy PDFs, this usually cuts the size dramatically while remaining perfectly readable on screen and fine for printing normal text.

Strong. Pages are rendered at 90 DPI with higher compression for the smallest possible file — ideal when you just need to get under an upload limit.

When image compression works best

Type of PDF Best level Typical saving
Phone or scanner scans Recommended / Strong 50–90%
Brochures and photo-heavy reports Recommended 40–80%
Text documents from Word or Google Docs Lossless 0–20%
Forms you still need to fill in Lossless 0–20%

Other ways to reduce PDF size

  • Remove pages you don't need with Delete PDF Pages, or send only the relevant part using Split PDF.
  • Compress images before creating a PDF: use Compress Image and then JPG to PDF.
  • Scan at a sensible resolution: 150–200 DPI in greyscale is enough for most text documents.

When combining several compressed files afterwards, use Merge PDF.

Frequently asked questions

Which compression level should I choose?
Try Lossless first for PDFs created from Word, Excel or design apps — it keeps text selectable and can remove some overhead, although savings are often small. For scanned documents and PDFs full of photos, Recommended usually reduces the size by 50–90% while staying readable on screen. Strong gives the smallest files for email and upload limits.
Why is text no longer selectable after Recommended or Strong compression?
These levels render each page as a compressed image and rebuild the PDF from those images, which is the most reliable way to shrink scans and photo-heavy pages in a browser. The look of the page is preserved, but text, links and form fields become part of the image. Keep the original if you need searchable text.
Why did my PDF hardly get smaller (or get bigger)?
A PDF made mostly of text and vector graphics is already efficient; turning its pages into images can even make it larger. In that case use Lossless or keep the original. Image-based compression helps most with scans and pictures.
Are my documents uploaded?
No. All compression happens in your browser, so confidential files never leave your computer.
Can I compress a password-protected PDF?
If a password is needed to open the PDF, it can't be compressed here. Remove the protection first with its password in a PDF application.
How can I reach a specific size, like under 1 MB?
Use Strong. If the result is still too large, split the document into parts with Split PDF, or remove unneeded pages with Delete PDF Pages before compressing.

Related tools

Merge PDFCombine several PDFs into one document in the order you choose — without uploading anything.Split PDFSplit a PDF into single pages, fixed-size parts or custom ranges, or extract just the pages you need.PDF to JPGTurn PDF pages into sharp JPG or PNG images at the resolution you need — right in your browser.Compress ImageMake images smaller by quality or to an exact target size in KB — in batches, without uploading.Delete PDF PagesRemove blank, duplicate or unwanted pages from a PDF by clicking them or typing page numbers.JPG to PDFCombine photos and images into one PDF, with A4, Letter or image-sized pages — in your browser.