Runs on your device
Compress PDF
Make a scanned document small enough to email. Images are downsampled and re-encoded; text is left exactly as it is. If your file cannot be made meaningfully smaller, we say so and give you the original back.
How to compress a PDF
Add your PDF
Drag the file onto the box above, or click it to pick it from your computer. One document at a time. Nothing is sent anywhere — the work happens on your own device.
Pick how hard to try
Recommended keeps images sharp enough to print. Strong is comfortable on screen and visibly softer on paper. Maximum is for when the file has to fit an upload limit and being readable is the only requirement. Each setting is a resolution cap and a JPEG quality, both listed so you know what you are choosing.
Compress
Your browser opens the document, finds the images it can re-encode, scales them down and writes a new file. Pages, text and page order are untouched throughout.
Read the result before you download
You get the real before and after sizes and the percentage saved. If the saving came to less than 5%, the tool says the file is already compact and hands you the original rather than a re-encoded file that is no better.
What you get
It tells you when it cannot help
A text-only PDF has almost nothing in it that browser-side compression can touch. Rather than shuffling bytes and reporting a 1% win, the tool says the file is already compact and returns your original untouched.
Text stays sharp; images are re-encoded
Only embedded images are resampled. Text remains real text — selectable, searchable and sharp at any zoom — because nothing on the page is rasterised. That also means the saving comes entirely from the images, which is why scans shrink and text does not.
Your file stays with you
The compression runs in your browser, on your own device. The document is never uploaded, so there is no copy on a server of ours to leak, to hand over, or to forget to delete.
Free, no account, no watermark
No size limit of our own and nothing stamped on the output. Open the page, compress, close the tab.
Frequently asked questions
Why did my PDF barely get smaller?
Almost certainly because it is mostly text. Compression in a browser works by finding embedded images, scaling them down and re-encoding them, and a text-heavy PDF has few or none — the text itself is already stored as compact drawing instructions, not as pixels, and there is nothing left to squeeze out of it. Documents made of scanned pages are the opposite case and often lose more than half their size. When we cannot save at least 5% we tell you so and give you back the original file rather than a re-encoded one that is no smaller in any way that matters.
Does compressing a PDF lose quality?
Yes, for images, and we are not going to pretend otherwise. Every image that gets re-encoded is scaled down to the resolution cap you chose and written as a JPEG at the quality you chose, and JPEG is a lossy format — that loss is where the saving comes from. Text and vector artwork are not touched at all and stay sharp at any zoom, because nothing on the page is rasterised. If you need images preserved exactly, this is the wrong tool: there is no lossless setting that would also make a scan meaningfully smaller.
What exactly is removed from my document?
Besides re-encoding images, the tool deletes things a reader does not need to display the pages: annotations and comments, form fields and their contents, embedded attachments, page thumbnails, document-level JavaScript, and the XMP metadata packet. All of those are real losses rather than free wins, so the result tells you how many annotations and attachments went. If your document is a form somebody has filled in, or carries comments you want to keep, compress it after you have finished with those — or do not compress it at all.
Are there image types you leave alone?
Several, and deliberately. Bilevel scans stored as CCITT or JBIG2 are already far smaller than any JPEG we could produce from them, so re-encoding one would make your file bigger and blurrier — we skip them. JPEG 2000 is a format browsers cannot write back out. Images with transparency, stencil masks, indexed palettes or CMYK colour are skipped because converting them through a canvas would shift colours or lose the mask. Anything already at or below your chosen resolution is left as it is. The result reports how many images were skipped, so a small saving always has a reason you can see.
Do you shrink the fonts too?
No, and we do not intend to. Subsetting fonts — throwing away the glyphs a document does not use — is the other big lever desktop tools pull, and it is the one thing here we have decided not to attempt. Doing it correctly means parsing and rebuilding glyph tables for every font format a PDF can embed; doing it incorrectly produces a document whose text renders as blanks or as the wrong letters, which you would discover after sending it to someone. A tool that runs in a browser tab is not where that risk belongs.
How do the three settings differ?
Each is a resolution cap plus a JPEG quality. Recommended caps images at 150 DPI at quality 0.75, which stays comfortably printable — a scanned page at that setting still looks like a scanned page rather than a compressed one. Strong uses 120 DPI at 0.6, which reads well on screen and is visibly softer in print. Maximum uses 96 DPI at 0.45: screen resolution, with JPEG artefacts you can see if you look, for when a size limit is the binding constraint. Images already below the cap are not enlarged or re-encoded to fit it.
Is my page count or page order affected?
No. Compression never adds, removes or reorders a page, and never changes the page size. The document you get back has the same pages in the same order at the same dimensions; what changed is the resolution of the images drawn on them and the removal of the extras listed above. If you want fewer pages, use the split tool; if you want them turned, use rotate.