Compress PDF
Make a PDF smaller by re-encoding its images, with the text left intact. Everything runs locally with zero file uploads.
- In
- Out
Drop a PDF to compress
Photos and scans inside it are downsampled and re-encoded; text stays sharp. The file never leaves your device.
Reduce a PDF's file size without uploading it
This PDF compressor makes a document smaller by finding the photos and scanned pages inside it, downsampling the ones stored at more resolution than a page needs, and re-encoding them as JPEG at the quality you choose. Everything else — the text, vector drawings, fonts, links and bookmarks — is copied across untouched, so the result stays sharp, searchable and selectable. The whole job runs on your device: the PDF is never sent to a server.
How to compress a PDF
- Drop a PDF on the page or choose one from your device.
- Pick a compression level. Recommended suits most documents; Strong is for when the file has to fit an email or upload limit.
- Compare the first page before and after, and check the new size and how many images were re-encoded.
- Download the smaller PDF, or send it straight to another tool such as Merge PDF.
What actually makes a PDF big
Text is cheap: a hundred pages of it rarely add up to more than a megabyte. What makes a PDF weigh tens of megabytes is almost always images — phone photos dropped into a report at their full 12-megapixel resolution, scans saved losslessly at 600 DPI, screenshots stored as uncompressed bitmaps. A page printed on A4 never needs more than about 2,000 pixels across, so most of those pixels are paid for and never seen.
That is where this tool works. Each image is decoded, scaled down so its longest edge fits the limit of the chosen level, and stored again as JPEG. An image is only replaced when the new version is clearly smaller; one that is already well compressed is left exactly as it was.
What the compression levels do
- Light
- Images up to 2,400 px on the longest edge, JPEG quality 82. Differences are hard to see even zoomed in; good for documents that may be printed.
- Recommended
- Images up to 1,600 px, quality 68. Sharp on screen and fine on paper, and usually the biggest saving for the least visible change.
- Strong
- Images up to 1,100 px, quality 50. For getting under an email attachment or form upload limit; photos soften, text is unaffected.
- Custom
- Set the JPEG quality and the longest image edge yourself, including keeping every image at its original size.
Why some PDFs barely shrink
A PDF that is mostly text, or one exported by a program that already compressed its images well, has little left to take out. This tool does not rasterise pages, strip fonts or throw away the text layer to reach a number — those tricks make a file smaller by making it worse. Instead it re-encodes what can be re-encoded and repacks the file's internal structure, and if the result is not smaller than the original it tells you and lets you keep the original.
A few image types are deliberately left alone: CMYK and spot-colour images for print, black-and-white fax-style scans (which are already tiny), JPEG 2000, and transparency masks, where lossy compression would leave halos around edges. If you need the pages as pictures instead, use PDF to JPG; to shrink any other kind of file, try Compress & Archive.
Private by design
Contracts, bank statements and medical records are exactly the PDFs people need to shrink, and exactly the ones that should not be uploaded to a stranger's server. Here the file is read and rewritten in your browser, the images are re-encoded by a Rust codec compiled to WebAssembly running in a Web Worker, and nothing leaves your device. You can switch off your connection after the page has loaded and it still works. Turn on Remove document metadata to also drop the title, author and creating software stored in the file.
Frequently asked questions
- How do I compress a PDF for free?
- Drop the PDF into the compressor, choose a level and download the result. There is no sign-up, no watermark and no file-size limit beyond what your device's memory can hold.
- Does compressing a PDF reduce its quality?
- Only the images change, and only as much as the level you pick. Text, vector graphics and fonts are copied exactly, so they stay perfectly sharp. On Light or Recommended, image changes are hard to notice.
- How do I compress a PDF to under 1 MB or 200 KB?
- Start with Strong. If the result is still too big, switch to Custom and lower the quality and the longest image edge. A PDF whose size comes from text or fonts rather than images cannot be pushed much further without losing content.
- Why did my PDF hardly get smaller?
- Its size is not coming from images, or its images were already well compressed. The tool never makes a file larger: if the result would not be smaller, it tells you and offers the original.
- Is the text still searchable after compression?
- Yes. Pages are not turned into pictures; the text layer, links and bookmarks are kept as they were.
- Can I compress a password-protected PDF?
- No. An encrypted PDF has to be unlocked with its password in a PDF reader and saved without protection first.
- Is my PDF uploaded anywhere?
- No. The file is processed entirely in your browser and never sent to a server.