Compress a PDF to 500 KB

Make a PDF smaller by re-encoding the images inside it, dropping duplicated objects and clearing metadata, without sending the document anywhere.

Drop your files here

.pdf · up to 300 MB

Choose files

How to Compress PDF

1
Drop your PDF
Add one file or up to twenty at once. Each document is opened by your own browser, so nothing is uploaded and nothing waits in a queue.
2
Pick a compression level
Best quality keeps images at 300 DPI and quality 85. Balanced goes to 150 DPI and quality 65. Smallest file drops to 96 DPI and quality 45. Or pick Target size with a goal such as 500 KB, and the quality and resolution are found for you.
3
Download the smaller file
The result keeps every page, all text and all form fields. Several files come back as one ZIP archive; each name ends in -compressed, or in the target, such as -500kb or -smallest, when you compress to a size.

Where the 500 KB limit comes from

Some systems cap attachments at half a megabyte: a content management system on shared hosting, a helpdesk that keeps every ticket attachment, a learning platform where a whole class uploads homework on the same evening, a procurement portal or a company intranet. Such a cap protects their storage rather than a reviewer's patience. This page starts the compressor with 500 KB selected, the smallest target on the list at which a densely typed page keeps its full 300 DPI.

How many pages stay sharp at 500 KB

Measured with the same JPEG encoder the tool uses, a densely typed page from a 300 DPI scanner weighs about 425 KB at quality 65, where the search starts, so one such page keeps its full resolution. Two already miss the target at quality 45, the lowest the search goes at full resolution, so from there the tool lowers the resolution instead: two or three dense pages come back at 150 DPI, four or five at 96 DPI and six to nine at 72 DPI, all at quality 45 or better. Pages with only a few paragraphs come to between 90 and 170 KB each, so three of them keep full resolution, and four do when they are on the light side. From ten dense pages on, the quality at 72 DPI goes down towards 20, around 25 KB per page: fine for reading on a screen, rough for small print.

Tickets, chats and why zipping a scan does not help

A PDF keeps typed text searchable and copyable, which a photo of the page cannot, so it remains the better attachment for a ticket or a chat. Attach the compressed copy and keep the original: the tool never overwrites your file but saves a new one with -500kb added to the name. Zipping will not get a scanned PDF under the limit, because its weight is JPEG data that is already compressed, and some helpdesks refuse archives anyway. If the measured minimum of a long document is above 500 KB, cut it with Split by size, which makes parts that each stay under a limit you set.

Compress a PDF to 500 KB on a phone and send it from there

The page works in the phone's own browser and takes the document from Files on an iPhone, Downloads on Android or a cloud folder; all the work happens on the phone, so a weak connection only delays opening the page. On an iPhone, tapping download brings up the Share sheet, which sends the file straight to WhatsApp, Telegram or Mail; on Android it lands in Downloads, where the messenger's attach button finds it. Several PDFs can go in together: the main button saves one ZIP, while Download one by one gives each file its own button, which suits a chat better than an archive. A file that cannot get under 500 KB at all, like a dense scan of twenty-odd pages, is left out rather than sent oversized, and the warning next to the download button names it.

The document never leaves your computer

Compression runs inside your browser tab, in a background thread on your own machine. The PDF is not uploaded, not copied to a server and not stored anywhere for us to delete later, which is why contracts, payslips and medical scans can be compressed here. Close the tab and everything still in memory is gone with it.

Frequently asked questions

Why did my PDF barely get smaller?

Because it has little or no raster content. Text, fonts and vector graphics are already compressed inside a PDF and are copied over untouched, so a file of pure text has almost nothing left to squeeze. Files built from scans or photographs shrink the most.

What is the difference between the three levels?

They set two numbers: JPEG quality and the resolution ceiling. Best quality uses quality 85 and 300 DPI, Balanced uses 65 and 150 DPI, Smallest file uses 45 and 96 DPI. Lower numbers mean smaller files and softer images; page count and text are identical in all three.

Will my scanned pages look worse?

At Balanced and Best quality, scanned text stays sharp enough to read comfortably on screen and to print. At Smallest file, photographs and colour gradients show visible artefacts and fine print softens. Try Balanced first and compare before you commit to a harsher setting.

Does my file get uploaded to a server?

No. The document is parsed, re-encoded and rebuilt by your own browser. No part of it travels over the network, and nothing of yours is stored anywhere. Compression also works with the connection switched off once the engine has loaded, which happens with the first file you add.

Is the text layer still searchable afterwards?

Yes. Text is never rasterised here, so every word stays selectable, searchable and copyable, and bookmarks, links and form fields keep working. Only the embedded images are re-encoded, which is what makes the file smaller in the first place.

Why can a password-protected PDF not be compressed?

Because its contents are encrypted, and the images cannot be read without the password. Remove the protection first with the password removal tool, compress the plain file, then apply a password again if you still need one.

How small can a vector or text-only document get?

Usually a few percent at best. Such a file is mostly font data and drawing instructions, both already packed by the format itself. When there is nothing raster to work on, the tool says so plainly instead of handing back a file of the same size.

Can I compress several PDFs at once?

Yes, up to twenty files in one go, with the same level applied to each. Every document is processed separately in your browser and the results arrive together in one ZIP archive, with each file keeping its original name plus a suffix: -compressed for a level, or the target, such as -500kb, when you compress to a size.