Compress PDF
Shrink a PDF's file size by re-optimizing its pages.
🔒 Processed locally — nothing is uploadedOne PDF file — add multiple with Pro
Related tools
A 40MB PDF that won't attach to an email is almost always a scanned document with high-resolution images baked into every page. Here's honestly what this tool does about that, and where it will and won't help.
Why PDFs get so large
A PDF's size usually comes down to what's embedded inside it: high-resolution scanned images, uncompressed photos, or embedded fonts. A ten-page scanned document at 300 DPI per page can easily reach 30–50 MB, while a ten-page Word-exported PDF with the same text might be under 500 KB — the difference is almost entirely about images, not text.
How this tool actually compresses a PDF
Each page is re-rendered as an image at a controlled resolution and re-saved into a new PDF at your chosen quality level — the same underlying approach a scanner-compression tool uses. This is genuinely effective at shrinking image-heavy and scanned PDFs, often by 60–90%, because it directly controls the resolution and compression of what's actually taking up the space.
Choosing a compression level
Best quality keeps resolution high and is a safe choice when the PDF will be viewed zoomed-in or printed. Recommended balances file size and clarity for typical screen viewing and email attachments. Smallest file pushes resolution and JPG quality down aggressively — good for hitting a strict upload limit, at the cost of visibly softer text and images if someone zooms in.
Where this approach won't help
If your PDF is already mostly text — an exported Word document, an e-book, a text-based report — it's likely already small, and rasterizing it will probably make it larger, not smaller, while also losing the selectable text. This tool is specifically built for the common case that actually causes oversized PDFs: scanned documents and image-heavy files.
Check what's actually making your PDF large
Before compressing, it's worth a quick sanity check: open the PDF and see whether it behaves like a document (you can click and select individual words of text) or like a scan (clicking just selects the whole page as if it were one image). If you can select individual words, you're likely looking at a text-based PDF that's large for some other reason — embedded fonts, high-resolution images used as illustrations, or unnecessarily large embedded photos — and this tool's rasterizing approach will trade that selectable text away for a size reduction that might be modest. If clicking selects the whole page, it's already an image-based scan, and this tool is exactly the right fit.
Frequently asked questions
Will I still be able to select or search the text afterward?
No — compressing rebuilds every page as an image, so the output behaves like a scan even if the original had real text. Keep your original file if you need searchable text later.
My PDF didn't get much smaller — why?
If the original was already mostly text with few or no embedded images, there's very little for this approach to compress. That's a sign the file was already efficient.
Which compression level should I pick for email?
"Recommended" is a good default for email attachments. If you're still over the limit, try "Smallest file" next.
Is this the same as what online "PDF compressor" tools do?
Most tools that dramatically shrink scanned PDFs use this same rasterize-and-recompress approach — the difference here is it happens entirely locally instead of on a server.
Can I compress just certain pages, not the whole document?
Not currently — compression applies uniformly to every page. If only some pages are large, consider extracting just those with our Split PDF tool first, then compressing that smaller portion.
How does this compare to desktop tools like Adobe Acrobat?
The underlying approach for image-heavy files is similar — reducing image resolution and re-encoding — though desktop tools sometimes offer additional options like font subsetting that this tool doesn't attempt.