Compress PDF files
Shrink PDFs that are too big to email or upload. Smart mode recompresses the images inside the PDF while keeping text sharp and selectable; extreme mode rasterizes pages for the smallest possible files. Everything runs in your browser.
100% private: files are processed in your browser and never uploaded to any server.
How it works
- Drop one or more PDFs into the box — compression starts automatically in smart mode.
- Adjust the mode or image quality if you need a smaller file, and compress again.
- Download each compressed PDF — the size saving is shown next to every file.
What is actually taking up the space
Before compressing, it helps to know why a PDF is big. Vector text and simple graphics weigh almost nothing; the size nearly always comes from images — photographs, logos and, above all, scanned pages, which are really just pictures of paper. A 20 MB PDF is almost never 20 MB of text. Compression works by targeting that image data, which is why results vary so much between an image-heavy scan and a plain text document.
Smart mode versus extreme mode
Smart mode is the right default. It keeps the PDF's structure and only re-encodes the embedded images at a lower resolution or quality. Text stays vector-sharp, selectable and searchable — you simply get a lighter version of the same document. It shrinks the heavy part and leaves the light part alone.
Extreme mode is the fallback for when you must hit a hard size limit. It rasterizes each page into a single flat image and rebuilds the PDF from those, which reaches much smaller sizes but turns the text into a picture — no longer selectable or searchable. Use it only when a strict cap leaves no choice, and prefer smart mode the rest of the time.
Why some PDFs barely shrink
If a PDF is mostly text, or its images are already well compressed, smart mode has little to remove — you might save only a few percent, and that is normal, not a failure. The document was already efficient. When you genuinely need it smaller, extreme mode will get there by rasterizing, at the cost of selectable text. There is no way around that trade-off: keeping crisp selectable text and reaching a tiny size are, for a text document, in direct tension.
Frequently asked questions
What is the difference between smart and extreme mode?
Smart mode only recompresses the images embedded in the PDF: text stays vector-sharp, selectable and searchable. Extreme mode converts each page into a compressed image — files get much smaller, but text can no longer be selected. Use extreme only when you must hit a strict size limit.
Why did my PDF barely shrink?
If a PDF is mostly text or its images are already highly compressed, smart mode has little left to squeeze. Switch to extreme mode for a guaranteed reduction — at the cost of selectable text.
Does compression reduce visual quality?
Smart mode at the default quality is visually indistinguishable for most documents. Lowering the quality slider trades visible detail for size, which matters mainly for photos and scans.
Is my PDF uploaded to compress it?
No. Compression runs entirely in your browser — your document never leaves your device, no matter how large it is.
Will compression blur my text?
In smart mode, no — text is never re-rendered, so it stays perfectly sharp. Only in extreme mode does text become part of a page image, where heavy compression can soften it.