Compress PDF
Compress PDF online free: pick a level or set an exact size like 200KB or 1MB. Runs in your browser, so your PDFs are never uploaded.
Drag & drop PDF files here
Everything happens in your browser: your PDFs are never uploaded anywhere.
Good quality and a much smaller file. About 170 dpi.
How to compress a PDF
Three steps, all in your browser.
Add your PDF
Drag and drop one or more PDFs, or click to browse. Nothing is uploaded.
Choose level or size
Pick Light, Balanced, Strong, or Maximum, or switch to file size and enter the limit you need.
Compress and download
See how much smaller it got, then download the compressed PDF.
Nothing uploaded
PDFs are compressed in your browser, so contracts, IDs, and scans never leave your device.
Level or exact size
Pick a preset, or give it a target like 200KB and it finds the best quality that fits.
Text stays sharp
Only the images inside are recompressed, so text stays selectable and searchable unless you choose to flatten.
Frequently asked questions
Drop your PDF into the box above, choose a level (Light, Balanced, Strong, or Maximum) or switch to "By file size" and enter a target, then click Compress. Everything runs in your browser.
Most of a PDF's size is usually the pictures inside it: scanned pages and photos. Images stored as JPEG are recompressed at a lower quality and, if they are larger than they need to be, at a smaller pixel size. Text, fonts, and links are not touched, so text stays sharp and searchable.
A PDF made from a document (Word, LaTeX, a web page) is mostly text and fonts, not images, so there is little to recompress. Images stored in other ways, such as PNG-style images, images with transparency, or CMYK images, are also left as they are, and the result tells you how many images were skipped. To shrink a text-only PDF much further, use the Maximum level, which flattens every page into a picture.
Flattening turns each page into a picture of itself. That can reach very small sizes, but the text can no longer be selected, searched, or copied, and links stop working. It is off unless you choose Maximum or allow it when a size target can't be met any other way.
Some PDFs can't get that small without flattening (for example, long text documents). When that happens the result says it got as close as it could, instead of claiming success, and you can choose to allow flattening and try again.
The result is at or under your target, as close to it as the search gets, so quality is not thrown away for nothing. MonsterConvert counts 1 KB as 1,000 bytes, so the file also passes a site that counts 1,024. If the PDF is already smaller than the target, it is returned unchanged.
Rewriting a PDF invalidates a digital signature and can break PDF/A conformance, so you'll see a warning when either is detected. Password-protected PDFs can't be compressed: unlock them in your PDF viewer first (open it and Print -> Save as PDF), then add that copy.
No. The PDF is compressed inside your browser using WebAssembly, so it never leaves your device. That makes it safe for contracts, IDs, and other private documents.
Because everything runs on your device, very large PDFs need a lot of memory. Files over 50 MB show a warning, and files over 250 MB are refused. If yours is that big, split it first and compress the parts.