SimpleSize.app
Sign in
Back to Tools

Compress PDF

Reduce PDF size online: make a PDF smaller while its text stays sharp and searchable. Free, no signup.

Drop PDF file here or click to browse
Select a PDF file to compress (up to 100 MB)
Recompresses the images inside the PDF and keeps text as text. Choose a level from Aggressive to High quality; if the PDF cannot get smaller, you get the original back.
Your PDF is compressed on our server in a temporary folder that is deleted as soon as the result is sent back. Nothing is stored.

Why a PDF is large, and what this PDF compressor shrinks

Most of a PDF's size is usually its images: photos, charts saved as pictures, and on a scanned document every single page. Embedded fonts and images repeated on many pages add the rest. Text itself takes very little space.

This PDF compressor rewrites the file with Ghostscript. It recompresses and, if you ask, downscales the embedded images, keeps only the characters of each font that the document uses, stores a repeated image once and packs the rest of the file tighter. Text and vector drawings stay text and vectors, so they stay sharp and searchable.

  • Scans and photo-heavy PDFs

    Shrink the most, because nearly all of their weight is images.

  • Exported documents

    Shrink well when they hold pictures or full embedded fonts, less when they are mostly text.

  • Text-only PDFs

    Are small already. The gain is little, and sometimes there is none, in which case you get your original back.

Want the theory behind it, lossless versus lossy? It is in PDF compression explained.

Making a PDF from photos?

Since images are most of the weight, shrink the photos with the image compressor before you put them in the PDF.

Pick a compression level

The three levels in the Compression Level menu:

LevelWhat happens to the imagesUse it for
Aggressive (screen) Strongest recompression and lower resolution Reading on a screen, uploads with a small size cap
Balanced (ebook) Default Clear recompression, images stay sharp on screen Email, sharing and most everyday PDFs
High quality (printer) Light recompression at print resolution Printing, and documents you will keep

Two more controls fine-tune it. Image quality sets how strongly the photos inside the PDF are recompressed: lower is smaller. Downscale embedded images caps their resolution in DPI, which is the biggest saving on a scan made at a high DPI. What DPI means for a page is explained in what is image DPI.

How to reduce PDF file size

  1. Drop the PDF

    Pick a PDF up to 100 MB. It must be a complete, unlocked file.

  2. Choose the level

    Start with Balanced. For a smaller PDF, lower Image quality or downscale the images; for print, pick High quality.

  3. Compress and download

    Click Compress PDF, check the new size, and download the smaller file.

  • 100 MB per PDF
  • Original back if it cannot get smaller
  • Not stored deleted as soon as it is sent back

What stays the same in a compressed PDF

Kept

  • Text, selectable and searchable
  • Vector drawings, tables and page layout
  • Page order and page orientation

Changed

  • Embedded images, recompressed and optionally downscaled
  • Fonts, reduced to the characters the document uses
  • Digital signatures, which no longer validate after any rewrite

Signing a PDF? Compress it first and sign the smaller file, because any change to a signed PDF breaks the signature.

PDF compressor questions

Pick High quality and keep the original DPI. Text and drawings never lose quality at any level, because only the images inside are recompressed, and High quality keeps those at print resolution.

It is probably mostly text, or it was optimized before. The tool automatically tries a stronger pass when the first one does not help, and if nothing comes out smaller you get your original back instead of a bigger file.

Use Balanced first. If it is still too big, lower Image quality or downscale the images to 150 DPI, which still reads well on screen. The limit of each provider is in email attachment limits, and for storage rather than email, see compress files for Google Drive.

Yes, and scans shrink the most, because every page is an image. Use Downscale embedded images to lower their resolution; which DPI suits reading or printing is covered in PDF compression explained.

Yes. Text stays text, so you can still select, copy and search it. A scanned PDF without a text layer had nothing to search in the first place.

Yes. A signature covers the exact bytes of the file, and compression rewrites them. Compress first, then sign.

Yes, with no account and no watermark, for PDFs up to 100 MB. Your file is deleted as soon as the result is sent back.