Compress PDF

How to compress a PDF

Add your documents, choose how much image quality to keep, and download the smaller versions. The size before and after is shown for every file, so you can check whether the result is under the limit that brought you here before you download it.

Everything runs in your browser. Once the page has loaded, the tool works with the network disconnected, which is the simplest proof that no document is being sent anywhere.

What actually gets smaller

Almost all of the space in a large PDF is taken up by pictures: scanned pages, photos pasted into a report, a high-resolution logo repeated on every page. Compression re-encodes those images at a lower quality and rewrites the file around them.

That means the result depends far more on what is in your document than on the setting you choose:

• A scanned document — a contract photographed or run through a scanner — is effectively a stack of photographs, and usually loses most of its size.
• A report with photos or charts falls somewhere in between, depending on how many there are and how large they were to begin with.
• A text-only export from Word, Pages or Google Docs will barely move. There is nothing to squeeze: text is already stored compactly, and no tool running in a browser can change that.

If your file is in the last group, you will be told plainly instead of being shown a tiny saving dressed up as a win. Splitting the document and sending only the pages that matter is often the better answer, and that tool is linked below.

Choosing a setting

The lowest setting is meant for email attachments and upload forms, where the document only has to be readable on a screen. The middle setting keeps more detail in photographs and is a reasonable default for anything being shared for reference. The highest setting preserves the most detail for documents that may be printed, but gives you a larger file in return.

If the first result is not small enough, try a lower setting rather than compressing the same file twice — a second pass over an already compressed document usually adds size rather than removing it.

What is kept, and what is not

Text stays text: selectable, searchable, and readable by a screen reader. Page size, orientation and links are carried through unchanged.

Document metadata — the author name, the software that produced the file, the creation date — is dropped. That is a small privacy improvement, and it is worth knowing before you send a file on to someone else.

Digitally signed documents are refused rather than quietly broken, because rewriting a file invalidates the signature it carries.

Nothing is uploaded

The documents worth compressing tend to be the ones worth keeping private: contracts, medical scans, tax paperwork, identity documents for an application form. Sending one to somebody else’s server to save a few megabytes means handing over the whole document, not just its size.

There is no server here to receive it. The compression happens on your own device, no copy is created anywhere else, and there is nothing to delete afterwards.

Why did my PDF barely get smaller?

Because there was little in it to compress. Compression works on the pictures inside a document, and a file exported from Word or Google Docs is mostly text, which is already stored efficiently. When that happens you are told so, rather than being handed a file that is 2% smaller and called a success.

Will the text still be selectable and searchable?

Yes. The pages are not turned into pictures. Text, links and page structure are left exactly as they were, and only the images inside the document are re-encoded.

Can I compress a password-protected PDF?

Not directly. Unlock it first in the program you normally open it with, then compress the unlocked copy. The tool tells you when a file needs unlocking instead of failing silently.

What about a digitally signed document?

A signed PDF is refused rather than processed. Compressing rewrites the file, and a signature stops matching the bytes it was calculated over, so a "compressed" signed contract would arrive with its signature broken.