Compress PDF - Reduce PDF File Size

Most "compress PDF" tools try to keep your text perfectly sharp and just nudge the pictures down a bit, which sounds smart right up until you feed one a scanned document and it barely moves. And a scan is usually the exact file you needed to shrink. Here the approach is inverted deliberately. It rebuilds every page as an image at a lower quality, so a 40-page scan of a signed lease, or a phone-camera stack of receipts, can drop by half or more. The honest trade is that a page which had real selectable text turns into a picture of that text. So it's the right call for scans and image-heavy files, and the wrong call for a born-digital report you need to keep searchable. All of it happens in your browser, which for a file type that's usually a contract, a tax form, or a passport scan, is the part that actually matters.

1. Add your PDF. Drag it onto the box or click to browse. You'll see the file name and its current size.
2. Pick how hard to compress. Less compression keeps pages crisp and trims a little. Recommended is the balanced middle most people want. More compression goes for the smallest file and softens fine detail.
3. Click Compress PDF. It works through the pages one at a time and shows progress as it goes.
4. Check the before and after. You get the original size, the new size, and how much smaller it came out.
5. Download. Your original on disk is left untouched, so the full-quality copy is always still there if the result comes out too soft.

A big multi-page file takes a little longer, since each page is handled on its own. A few dozen scanned pages usually finish in a couple of seconds.

This tool shrinks a PDF by flattening each page into an image. That single design choice explains almost everything about when it helps and when it doesn't.

Scanned documents shrink the most, and it isn't close. A scan is already a stack of photos wrapped in a PDF, so re-encoding those photos at a lower quality is exactly the kind of work that frees up real space. Half off is common, sometimes a lot more. Brochures, portfolios, slide decks exported to PDF, anything where the weight is pictures, all compress well for the same reason.

A text-only PDF is the opposite story. A born-digital document (one your word processor or an export button made, not a scanner) is already small and efficient, so there's very little to squeeze out. Worse, flattening its crisp text into an image can actually make the file a touch bigger while also stripping out your ability to select or search that text. When you hand it a file like that, the tool notices and tells you it was already well-optimized instead of pretending it did something. That warning is doing you a favor, keep the original.

So it comes down to one question about your file. If it's a scan or it's full of images, this is the right tool and you'll see a big drop. If it's a clean text document you need to stay searchable, compressing it here costs you the text layer for almost no size win, so you're better off leaving it alone or reaching for a tool that keeps the text intact.

You can compress as many times as you like for free, so the practical move is to aim at whatever limit you're fighting and check the result.

• Email attachments get bounced around 20 to 25 MB at most providers. Recommended clears that for the large majority of documents in a single pass.
• Web upload forms on job portals and government sites are stingier, often 2 to 5 MB. Start with Recommended, and if you're still over, step up to More compression.
• Quick sharing over chat or on a phone only needs to look fine on a screen, so More compression and its smaller file is usually the smart pick.
• Printing or keeping something for the long term is where Less compression pays off, holding detail while still trimming the file.

There's no penalty for trying. Run Recommended, read the two sizes it reports, and nudge one step in either direction until the file is both small enough and clear enough.

When you compress a PDF on most online tools, you're uploading it. Fine for a flyer. But PDFs are rarely flyers, they're offer letters, bank statements, medical results, passports. Handing one of those to an unknown server just to make it smaller is a real risk people take without a second thought.

Here there's no upload, no account, and no copy sitting in someone else's storage, because the whole job runs on your own machine. There is one thing the page still wants from us, though, and it is worth keeping separate from the privacy question. It does not work offline from a cold start, because the reader that opens your pages arrives on your first press of Compress in two parts, a 431,160-byte script and a 1,181,223-byte helper. The part that writes the smaller PDF back out is already on the page, so it is the reading half that stops you. Compress one document and both parts stay in your browser, which is when the wifi can go off and stay off.