Compress a PDF to 100 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.

Why 100 KB specifically

Almost nobody wants a 100 KB PDF for its own sake. The number comes from upload forms, such as visa applications, university portals, job boards and government e-services, that reject anything larger and say so only after you have filled in the rest of the page. This tool starts from that number instead of from a quality slider: you get the target, it works out what has to give, and it tells you what it did. If the result comes back at 96 KB rather than exactly 100, that is normal; compression cannot hit a byte count precisely, and landing just under the limit is the point.

What gets sacrificed to reach it

Images, in almost every case. A text-only PDF is usually well under 100 KB already, so a file that needs shrinking is a file with photographs or scans in it, and those are resampled to a lower resolution until the total fits. Text and vector graphics are untouched. They cost almost nothing and stay sharp. That is why a scanned document compressed to 100 KB looks softer while a report with a couple of illustrations often looks identical: the report only had to lose detail nobody was reading at full size anyway.

When 100 KB is not achievable

A fifty-page scan cannot become 100 KB and still be readable, and the tool says so rather than handing back grey mush. When that happens the realistic options are fewer pages, greyscale instead of colour, or a higher limit if the form allows one. Splitting the document and uploading the relevant pages is usually better than degrading all of them. If the form's limit is the problem rather than your file, it is worth checking whether it accepts a ZIP. Many do, and a zipped PDF of text compresses further.

Compress a PDF to 100 KB on iPhone or Android

The same page works in Safari on an iPhone and in Chrome on Android, with no app to install: open it, tap the drop zone and pick the document from Files, Downloads or a cloud drive. The compression runs on the phone itself, so a slow connection does not matter and nothing has to finish uploading before the work starts. On an iPhone the result is saved through the Share sheet, where Save to Files keeps it on the phone and Mail or WhatsApp attaches it straight away; Android puts a plain download into the Downloads folder. A portal that only accepts uploads from a desktop browser can still be fed from the phone: compress here, save to a cloud drive, and open that drive on the computer.

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.