How to Compress a PDF to Fit an Email or Upload Limit

You try to attach a PDF and get "file too large". Or a job portal, visa form or university application says the upload must be under 2 MB — and your scanned documents are 12 MB. The fix is to compress the PDF, and you can do it for free without installing anything.

A stack of envelopes tied with string

Why PDFs get so big

Text takes almost no space in a PDF. What makes files heavy is images: scanned pages, phone photos of documents, and pictures pasted into reports. A single page scanned at high resolution can easily be 1–3 MB, so a 10-page scan quickly passes common limits.

That's also why compression results vary so much. A PDF full of scans can shrink by 70–90%. A PDF that is mostly text is already compact, so there is little to remove.

How to compress a PDF

Open the free Compress PDF tool and choose your file.
Pick a compression level (see below) — Strong is the best starting point.
Click Compress PDF and check the before/after size.
Download the compressed PDF.

The file is processed in your browser and never uploaded, which matters for IDs, contracts and bank documents. If a level can't make your PDF smaller, the tool tells you instead of handing you a bigger file.

Which compression level should you choose?

Basic — lossless. It cleans up the file's internal structure; text stays selectable and searchable. Best for text documents, but the savings are usually small.
Strong — each page is redrawn as a compressed image at 120 DPI. This gives big savings on scans and photo-heavy files and still reads well on screen and when printed at normal size.
Extreme — pages become images at 90 DPI. The smallest file, with visibly softer detail. Fine for documents that will only be read on screen.

One trade-off to know: after Strong or Extreme, text can no longer be selected or searched, because each page is now an image. If you need copyable text, use Basic.

Getting under a specific limit

Upload forms often ask for 1, 2 or 5 MB, and Gmail attachments are capped at 25 MB. If your file is still too big:

Step down a level. Try Extreme if Strong wasn't enough.
Split it. Upload forms often accept several files. Use PDF Split to break the document into parts, then compress each one.
Remove pages you don't need with Delete PDF Pages — blank backs of scanned pages are a common culprit.
Fix the source. If you're scanning, a 150–200 DPI scan is plenty for most forms and starts out much smaller than 600 DPI.

Labelled office binders on a shelf

FAQ

Does compressing a PDF reduce quality? Basic doesn't. Strong and Extreme reduce image resolution, which is how they save so much space — at normal viewing sizes the difference is small.

Why didn't my PDF get smaller? It's probably mostly text, or it was already compressed. Big savings come from scanned and image-heavy PDFs.

Can I compress a password-protected PDF? Remove the password first with Unlock PDF, compress, then add it back with Protect PDF if needed.

Is my file uploaded? No. Compression runs entirely in your browser.

Try it now

Shrink your file with the free Compress PDF tool.