Compress PDF Smaller files, no upload

How to compress PDF files

This free compress PDF tool makes PDF files smaller so they fit email limits and upload forms, and it does the work in your browser instead of on a server. Add a PDF, choose Light, Balanced or Strong, and press Compress PDF. You see the size before and after, and the smaller file downloads automatically. If a level cannot make your file any smaller, the tool tells you instead of handing back a bigger file.

What the three levels really do

Many compressors promise huge savings without saying how they get them. Here is exactly what happens to your file.

Light: lossless

The PDF is rebuilt with compressed object streams and without unused leftovers. Nothing visible changes: text, vectors, images, links and quality stay the same. Savings are usually modest, from a few percent to a third for files exported by older software. Use it for contracts and anything that must stay exactly as it is.

Balanced: re-render image-heavy pages

Pages that are mostly pictures, such as scans, photos and slides made of screenshots, are redrawn as JPEG images at 150 DPI, which is sharp on screen and fine for most printing. Pages that are mostly text are kept as they are, so their text stays selectable. This is where scanned documents lose most of their weight, often shrinking to a fraction of the original size. Any text on a re-rendered scan page becomes part of the image.

Strong: re-render every page

Every page becomes a JPEG at 110 DPI with stronger compression. This gives the smallest file, but text on every page turns into a picture: it can no longer be selected, searched or read aloud by screen readers, and links and form fields stop working. Use it only when size matters more than anything else, and keep your original.

Why your PDF is big in the first place

• Scans and phone photos. A page scanned at 600 DPI in color can weigh several megabytes on its own.
• Uncompressed or lossless images. Screenshots and PNG images inside slides add up quickly.
• Embedded fonts. Full font files are sometimes embedded for every weight used.
• Leftovers. Some editors keep deleted objects and earlier versions inside the file.

If your PDF is mostly text exported from Word or Google Docs, it is probably already small and no tool will shrink it much. That is normal. A quick rule of thumb: a text page needs tens of kilobytes, while a color scan of the same page can need several megabytes. The second kind is where compression pays off, which is why Balanced mode targets those pages and leaves the rest alone.

Private compression, on your device

Well-known compress PDF services upload your file to their servers, process it and offer it back for download. For a bank statement, medical record, passport scan or signed contract, that is a copy you no longer control. This tool uses two open-source libraries, Mozilla's PDF renderer and pdf-lib, inside your browser. Your file is never sent to KissMySkills or anyone else, and you can disconnect from the internet after the page loads and it still works.

Tips to get the smallest file

• Try Balanced first. Only move to Strong if the result is still too big.
• In Advanced settings, 96 or 110 DPI is plenty for documents that will only be read on screen.
• For black-and-white text scans, a lower JPEG quality hardly shows and saves a lot.
• Still too large? Split the file into parts and send them separately.

Need to send the result with a cover note? Our AI email generator drafts it in seconds, the AI text summarizer can add a short summary of the document, and the rest of our free tools are on the free AI generators and tools page.

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