Compress PDF
Shrink your PDF file size right in your browser. Your file never leaves your device — compression happens 100% locally.
Drag & Drop PDF Here
or click to select a file from your computer
Shrink your PDF file size right in your browser. Your file never leaves your device — compression happens 100% locally.
or click to select a file from your computer
Almost always, images. A page of text is a few kilobytes — characters, coordinates, and a font. A scanned page is a photograph, and a colour scan at 600 DPI can be several megabytes on its own. If your 40 MB document is mostly scans, the scans are the entire problem and everything else is rounding error.
The other common causes are embedded fonts that were never subsetted, so the whole typeface ships instead of the glyphs you used; images placed at far higher resolution than they are displayed at, where a 4000-pixel logo appears two centimetres wide; and accumulated revision history, since PDFs can be saved incrementally with every earlier version still inside the file.
Compressing a PDF is not a single operation. Different tools do different things, and the trade-offs are worth knowing before you press the button.
Two checks save time. If the document is a scan and you need the text searchable, run OCR before compressing — recognition accuracy drops once you have thrown pixels away. And if the file only needs to be smaller for email, check the actual limit first: Gmail and most providers cap attachments around 25 MB, many corporate mail servers at 10 MB, and some at 5 MB. Knowing the target stops you compressing far harder than necessary.
If a document will not shrink usefully, it is often because it was already compressed. A PDF exported from a modern application is usually close to optimal, and squeezing it further mostly costs quality for a few percent of size. In that case, splitting the document or sending a link is the better answer.
Compression runs entirely in your browser. The file is read into memory by your own machine, processed there, and written back out to your downloads — there is no upload endpoint, so nothing is transmitted to us or anyone else. You can verify that by disconnecting from the internet after this page has loaded and compressing a file anyway; it will work. See the About page for the full mechanism.
The trade-off is that very large documents are limited by your device’s memory rather than by a server farm. On a phone or an older laptop, a several-hundred-page scanned file may be slow or may not complete. That is the cost of not uploading, and we think it is the right one for documents that matter.