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Compress PDF

Shrink a PDF by re-encoding its images and re-packing its streams. Text, links and form fields are left exactly as they are. Some detail is discarded to fit the target format; how much depends on the format and your settings.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

PDF · up to 200 MB each

or paste files from your clipboard

Ready when you are

Shrink a PDF by re-encoding its images and re-packing its streams. Text, links and form fields are left exactly as they are. Everything happens in this tab; nothing is sent anywhere.

⌘K to search converters

How to use it

1
Add your files
Compress PDF works with PDF. Drop them in, browse for them, or paste from your clipboard.
2
Choose your options
Tune the output settings — or leave the defaults, which are sensible.
3
Run it and download
Press the button and save the result. Everything happens on your device, and nothing is uploaded.

Privacy, in plain words

Is it safe? Your PDF is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your PDF is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

PDF is the format people use for exactly the documents they would not hand to a stranger. It matters more than it sounds, because of what PDFs usually are:

Tax returns

income, dependants, tax file or social security numbers

Passport and visa scans

the single most useful document for identity theft

Medical letters and results

a diagnosis is not something to leave on a server

Payslips

salary, employer, and usually your home address

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

What actually gets smaller

A PDF is usually large for one reason: the pictures inside it. Text is vectors and weighs almost nothing — a hundred pages of writing is a few hundred kilobytes. A single phone photo dropped into a report can be four megabytes on its own, and a scanned document is nothing but photographs, one per page.

So compressing a PDF means finding those images, decoding them, and re-encoding them smaller. The text, the links and the form fields are copied across untouched. That is why a text-heavy PDF barely shrinks and a scan can lose 90% of its size: the tool is working on the part that is actually big.

Images are re-encoded: Each embedded image is decoded and written back at a lower quality. This is the part that is lossy, and the only part.
Text stays text: Words remain selectable and searchable. Compression does not flatten your document into pictures — that would make it larger, not smaller, and would break copy and paste.
Structure is preserved: Links, bookmarks and form fields survive, because they are cheap to store and expensive to lose.

How much smaller, realistically

It depends entirely on what is in the file, and anyone promising a fixed percentage has not looked at yours. A scanned contract often drops by 70–90% because every page is a photograph. A text report with two logos might move by 5%, because there was never much to remove.

If a file barely changes, that is usually the honest answer rather than a failure: there was no image weight to reclaim. FileTools360 tells you the before and after rather than quietly returning the original and calling it compressed.

When a different tool is the right one

Compression is not the answer to every large PDF, and reaching for the wrong tool wastes a step.

You only need some of the pages: Splitting is far more effective than compressing. Ten pages out of two hundred is a 95% reduction with no quality cost at all.
The file is a scan you want to search: Compressing a scan keeps it a picture. Recognising the text first is what makes it searchable.
You are emailing several documents: Merging them into one PDF, then compressing once, beats compressing each separately.

Measured, not estimated

What this tool actually does to a file

Compressing a six-page document at the default Recommended setting. Measured here rather than in Node because most of the work is re-encoding the images inside the file, which needs a browser.

It depends entirely on the content: across the samples the result ranged from 2.8× smaller to about the same size, with a middle case 1.5× smaller.

Each row is one document, chosen because this tool behaves differently depending on what is inside the file.
Sample	In	Out	Change
An easy clipThe compressible end of the range — a clean tone, or a moving test pattern — where a codec does its best work.	6.7 KB	6.6 KB	−1%
A hard clipThe other end — pink noise, or dense video grain. Close to incompressible by design, and the worst case for every codec.	423 KB	148 KB	−65%

Produced by this site's own converter. The same code that runs in your browser, at the same default settings, so these are the bytes you would download.

Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.

About these formats

Accepts

Portable Document Format

Fixed-layout documents that look identical everywhere.

Extensions: .pdf
MIME type: application/pdf
Best for: Sharing documents · Printing · Contracts and forms
Compatibility: Universal.

Text, links and form fields are left alone: images are re-encoded and the streams are re-packed, so the page stays exactly as a reader sees it. Flattening every page to a picture is available as a deliberate choice, and says so on the control. If the PDF is mostly text there may be little to win — and FileTools360 will tell you rather than hand back a bigger file.

Good to know

Compress PDF — questions

How does Compress PDF work?

Shrink a PDF by re-encoding its images and re-packing its streams. Text, links and form fields are left exactly as they are. Add your files above, adjust anything you want to change, and press the button. The result downloads straight to your device.

Is there anything I should watch out for?

Is Compress PDF safe — are my files uploaded to a server?

No, nothing is uploaded. On most online tools, pressing the button copies your file across the internet onto a computer owned by that website, where it is processed and then sent back. That copy is what "upload" means. This tool does not do it: your file is read and processed by the browser you are using right now, stays on this device the whole time, and is discarded when you close the tab. Turn off your Wi-Fi after the page loads and it still works, which is the quickest way to confirm it.

Can I use this on confidential or personal documents?

Yes — that is the case it was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder: there is no transfer, no copy on anybody else's hardware, no retention period and no staff with access. Nothing about the file is logged either — not its name, not its size, not its contents.