PDF Compressor

Important: this compressor rebuilds PDF pages as images, so text may no longer be selectable or searchable after compression. It is designed for scanned documents, image-heavy PDFs, brochures and photos — not ordinary text or vector PDFs. Compression also requires JavaScript enabled; with JavaScript off you can read this guide but the tool controls will not appear.

Compress PDF online, in your browser

This free PDF compressor shrinks scanned and image-heavy PDF files without uploading them anywhere. It opens your PDF, renders each page to an image at a resolution you choose, compresses that image, and rebuilds a new, smaller PDF — all inside your browser. Because it works on the page images, it is ideal for scans and photo-heavy documents where most of the file size is pixels rather than text.

How to use the PDF Compressor

1. Click the upload area to choose a PDF, or drag and drop one onto it.
2. Check the file details — name, page count and original size.
3. Pick a compression level: High quality, Balanced or Smallest size.
4. Press Compress PDF and watch the per-page progress.
5. If the result is smaller, download the compressed PDF; if it isn’t, the tool offers your original instead. Press Clear to start again.

What PDF compression does

Compressing a PDF reduces its file size so it is faster to email, upload or store. For scanned and image-based PDFs, the images are usually the largest part of the file, so re-encoding them at a sensible resolution and quality can cut the size dramatically. This tool does exactly that, and then measures the real result rather than promising a fixed figure.

Why image-heavy PDFs benefit most

A scanned page is really a photograph of paper, and often stored at a much higher resolution than you need on screen. Re-rendering it at, say, 100–150 DPI and saving it as a JPEG can shrink it a lot while still looking clear. Ordinary text or vector PDFs, on the other hand, are already compact and store text as characters — turning them into images usually makes them larger and removes the selectable text, so this tool is not the right choice for them.

Best PDF compression settings

• High quality (~150 DPI) — best-looking output and still smaller for most scans; choose this when clarity matters.
• Balanced (~100 DPI) — the recommended middle ground between size and quality for everyday documents.
• Smallest size (~72 DPI) — the biggest reduction with lower visual quality; good for quick sharing where fine detail isn’t important.

There is no single “right” setting — try Balanced first, and switch to Smallest size if you need a smaller file or High quality if the text looks too soft. The tool always shows the real before-and-after sizes so you can decide.

Quality vs size, and selectable text

Lower DPI and lower JPEG quality make smaller files but reduce sharpness; higher settings look better but save less. Whichever you pick, remember the key trade-off: because pages are rebuilt as images, any selectable or searchable text becomes part of the image and can no longer be highlighted, copied or found with search. If keeping the text layer matters, this tool isn’t the right fit for that file.

Why some PDFs may not get smaller

If a PDF is already optimised, or is mostly crisp text and vectors, rasterising it can produce a file that is the same size or larger. This tool never hides that: it compares the actual byte sizes after processing, and if the result is not smaller it says so plainly and recommends keeping your original file. You will never see a made-up reduction percentage.

Privacy and local processing

Your PDF is processed locally in your browser and is never uploaded. There is no server processing, no cloud service and no account — the PDF renderer and image encoder run on your own device, so it is safe to compress private contracts, statements and personal documents. When you close the tab, nothing remains.

Is it private?

Yes — this is the whole point. Your PDF is compressed in your browser and is never uploaded, stored or shared. There is no tracking and no sign-up.