Compress PDF
Shrink a PDF by re-encoding the images inside it at a quality level you choose. You see the size before and after, and can dial the quality back up if it went too far.
Drop your file here
or click to browse
Pages are rebuilt as images, so text stops being selectable. Great on scans, pointless on plain text.
- ProcessingOn your device
- Uploaded to a serverNothing
- InternetNot needed
Don't take our word for it. Turn off your Wi‑Fi, then use this tool. It will work exactly the same, which is only possible because your file never goes anywhere.
Worth knowing
Best results come from image-heavy or scanned PDFs. A file that's mostly plain text is already small and won't shrink much — the tool will tell you when that's the case rather than pretending it worked.
What actually makes a PDF large
Almost every oversized PDF is oversized for one of three reasons, and they call for different fixes. Guessing wastes time, so it is worth knowing which one you have before you compress anything.
Scanned pages
A scan is a photograph of a page. At 600 DPI in colour, one A4 sheet can be several megabytes on its own, and the text inside it is not text at all — it is pixels. This is the most common cause of a huge file and the one that compresses best, often by 80% or more, because scanners routinely capture far more detail than anyone will ever look at.
Full-resolution photographs
A phone camera image dropped into a document is typically 4000 pixels wide. Printed at page width it needs perhaps 2500, and on screen far fewer. The surplus is invisible and costs megabytes per image.
Embedded fonts and duplication
Every font used has to travel with the file. That is normally modest, but a document assembled from several sources can carry the same font several times over. This is why a merged file is often larger than the sum of its parts.
How much compression is too much
- For email and general sharing, aim to get under 25 MB — the limit Gmail and Outlook both apply.
- For anything that will be read on screen, 150 DPI is indistinguishable from the original at normal viewing size.
- For anything that will be printed, stay at 300 DPI. Below that, printed text begins to look soft.
- For documents that must stay legally exact — signed contracts, filed accounts — compress the copy you send, not the one you keep.
If a file is still too large after compressing, the answer is usually to split it rather than to compress harder. Past a point, further compression is visible on every page and saves very little.
More on this: getting a PDF under the 25 MB email limit.
Questions people ask
How much smaller will my file get?
Scanned documents often drop by 60-90%. Text-only PDFs barely change, because there's very little to compress.
Will the text still be selectable?
On the strongest setting pages are rebuilt as images, so text becomes part of the picture. Lighter settings keep text intact — the tool says which is which.
Why did my file barely get smaller?
Because there was little to remove. Compression works by reducing image detail, so a document that is mostly real text has almost no slack in it. A file that will not shrink is usually already efficient — split it instead.
Will compressing make my text blurry?
Not for real text, which is stored as instructions rather than pixels and is unaffected. Text inside a scanned image is a picture and can soften if compressed hard — keep scans at 150 DPI or above.
Can I compress the same PDF twice?
You can, but the second pass gives back very little and the losses accumulate. If one pass has not done enough, reduce the resolution target or split the document instead.
Is compressing a PDF reversible?
No. Discarded image detail is gone for good, which is why it is worth keeping the original and compressing a copy.
How to use it
How-to guides · 5 August 2026 · 2 min
Your PDF is too big to email. Here's how to fix it.
Most email providers cap attachments at 25 MB. Here's why PDFs get so large, which fix actually works for your file, and how to shrink one without uploading it anywhere.
How-to guides · 21 August 2026 · 6 min
Word to PDF without losing your formatting
Converting a .docx to PDF is easy. Getting a PDF that looks exactly like the document did is where it goes wrong, and the reasons are always the same three things.