How to Compress a PDF Without Losing Quality

This compressor works by re-rendering each page as an image at your chosen quality and rebuilding the PDF around it. That means it shrinks scanned documents and image-heavy PDFs dramatically — think contracts you scanned, photo-filled reports, or brochures exported at full resolution.

It's less useful for plain text documents. If your PDF is mostly selectable text (like an exported invoice or a Word-to-PDF file), there isn't much image data to compress, and turning that crisp text into a flat image can actually offer little or no savings. If the tool reports 0% saved, it's telling you the file is likely text-based — in that case the original is already about as small as it gets, and you can keep it as is.

Start with Medium and look at the Saved percentage. If the result still looks sharp when you open it, try Low for an even smaller file; if text or fine detail looks fuzzy, step up to High. Because your original is never modified, you can compress, preview, and re-compress as many times as you like until the size-versus-quality trade-off feels right.

A practical rule: pick the lowest quality level where the document is still comfortable to read at normal zoom. For documents you'll only view on screen or email, Low or Medium is usually plenty. For anything you'll print, lean toward High.

Yes. The entire process runs locally in your browser using pdf.js and pdf-lib — your PDF is never uploaded to a server, so it never leaves your computer. That makes it a sensible choice for sensitive material like IDs, medical forms, financial statements, or signed contracts.

There's no account to create and nothing to install. You can even disconnect from the internet after the page loads and the tool will still compress your file, which is the clearest proof that the work is happening on your device and not in the cloud.

"It says 0% saved." Your PDF is probably text-based, so rasterising it doesn't shrink it. That's expected — keep the original.

"The text looks blurry." You compressed too aggressively. Re-run with a higher quality level (Medium or High) for sharper pages.

"My file is very large." Big scanned PDFs take a moment to process because every page is re-rendered on your device; let it finish rather than reloading. If it's near the size limit, the tool will let you know.