Compress PDF Online
Upload a PDF to preview it, then pick Low (−25%), Medium (−50%) or High (−75%) — each option shows its estimated output size before you compress. The file stays a real PDF with the same pages and layout; only the size shrinks.
Drag & drop your file here
or click to browse your device
Sizes are estimates from your first page. The result stays a real PDF — same pages, same layout, only smaller.
We adjust quality to land as close as possible. If your target cannot be reached without ruining quality, we will tell you honestly.
Why compress a PDF?
Big PDFs are a pain: email servers reject attachments over 20–25 MB, upload forms time out, and sharing a 60 MB scan over chat takes forever. To compress pdf files the smart way, you need to shrink them without turning the text into a blurry mess — which is exactly what GroPDF's compressor does. It rebuilds your document with optimized images and cleaned-up internals, so the file gets much smaller while staying perfectly readable.
How to compress a PDF
- Drop your PDF onto the page (or click to browse). It never leaves your device — compression runs locally in your browser — and you'll see a preview of it right away.
- Pick a compression level: Low shrinks the file by about 25% with near-original quality, Medium by about 50%, High by about 75%. Each option shows its estimated output size before you commit.
- Click the level you want and wait a few seconds while the tool processes your pages.
- Download your smaller PDF and check it looks right. Not happy? Re-run with a different level — it's free and unlimited.
Which compression level should you choose?
Low targets roughly 25% smaller with near-original quality — best for legal documents, portfolios, or anything headed to a printer. Medium targets about 50% smaller and is the sweet spot for everyday sharing, with no visible difference on screen. High targets about 75% smaller for tight attachment limits; text stays readable but photos may look slightly soft. The estimated size on each button is calculated from your actual file, so pick whatever fits your limit.
Tips for the best results
- Scanned PDFs shrink the most. Scans are mostly images, so compression can take a 40 MB scan down to under 10 MB.
- Already-small PDFs won't shrink much. If your PDF is mostly text, there's little fat to trim — that's normal, not a bug.
- Need to send it? After compressing, use Merge PDF to combine related documents before sending, so the recipient gets one tidy file.
Honest limitations
Compression can't work miracles: a PDF that's already optimized, or one made of vector graphics and text, may only shrink by 5–10%. And the High setting is lossy — if you need pixel-perfect images for print, stick with Low or keep the original. Your original file is never modified; you always download a new copy.
Steps at a glance
- Upload your PDF — you'll see a preview of the first page along with the original file size.
- Choose a compression level: Low (−25%), Medium (−50%), or High (−75%), each showing its estimated output size. Or pick a target size like 2 MB, 1 MB, 500 KB, or 300 KB.
- Click Compress PDF and wait a few seconds while the pages are processed.
- Download your smaller PDF. The file name, page count, and layout are unchanged.
Why compress PDFs with GroPDF?
Most PDF compressors upload your file to a server, queue it, and make you wait — or they slap on watermarks and daily limits. GroPDF compresses entirely in your browser, so there's no upload, no waiting in a queue, and no one else ever sees your document. You also get something rare: an honest size estimate before you commit. Each compression level shows its predicted output size, and the target-size mode tells you plainly if your goal can't be reached without ruining quality.
Common use cases
- Shrinking a scanned document so it fits your email provider's attachment limit.
- Reducing a portfolio or CV to upload to a job portal with a strict file-size cap.
- Making a large report small enough to share over WhatsApp or messaging apps.
- Freeing up storage space when archiving old PDFs.
Things to know
Compression works by re-rendering pages as optimized images, so text in the output is part of the page image rather than selectable text objects. Very small text may look slightly softer at High compression. Already-optimized PDFs (for example, ones exported with 'smallest file size' settings) may not shrink much further — the tool will tell you honestly if that's the case.
Frequently asked questions
Will compressing change my PDF's layout or pages?
No. The page count, page order, and layout stay exactly the same. Only the file size shrinks — the visual content is re-rendered at a lower quality setting you choose.
What's the difference between Low, Medium, and High?
Low reduces the size by roughly 25% with barely noticeable quality change — best for documents you'll print. Medium (about 50%) is a good balance for everyday sharing. High (about 75%) gives the smallest file but text and images will look softer, so it's best for screen-only viewing.
Can I compress to an exact size, like under 1 MB?
Yes. Below the three levels you'll find target-size cards (5 MB, 2 MB, 1 MB, 500 KB, 300 KB, or a custom value). GroPDF adjusts quality to land as close as possible. If your target can't be reached without making the PDF unreadable, it will tell you honestly instead of producing a useless file.
Is my file uploaded anywhere?
No. Compression happens entirely in your browser using JavaScript. Your PDF never leaves your device, which also means there's no upload wait and no file sitting on someone else's server.
Why didn't my PDF get much smaller?
Some PDFs are already efficiently compressed — for example, text-only PDFs exported with optimization settings, or files that are mostly vector graphics. In that case there's little redundancy left to remove, and GroPDF will show you a modest estimate rather than promising the impossible.
