Compress a PDF to 500 KB
Get a PDF under 500 KB and keep it sharp, without uploading it.
Runs entirely in your browser
Loading the tool…
Your file is opened by this page and never uploaded. It is not sent anywhere, and the page keeps working with the network off.
The gentlest setting that gets under it is found for you.
Lower squeezes harder. Below about 50% the difference starts to show on photographs, and sooner on text that was scanned.
Scanned pages are often far larger than anything that will read them.
- —Original
- —Compressed
- —Saved
500 KB is a generous limit, and that changes what compressing is for. At 100 or 200 KB the question is whether a file can fit at all; at 500 KB most can, and the question is how little needs to change. This page opens on 500 KB and keeps the gentlest setting that gets there, which for many files means pictures re-saved at high quality and not scaled down at all.
Typical files at this size are a scanned contract or form of several pages, a short report with photographs in it, or a set of receipts for an expense claim. Their text and fonts come through unchanged, and the pictures are only squeezed as far as the limit needs, so what you download should look the same as what you opened.
If the file is far over 500 KB, several megabytes of scan, the search goes further down the scale, and the result tells you the setting it ended on. That is the moment to look at the file before sending it.
How to use it
- Choose your PDF. It is read in this tab and never uploaded.
- Leave the size this page opened on, or pick another under Smaller than.
- Press Compress: the gentlest setting that gets under the size is found for you.
- Download the result, which is already named as the compressed copy.
Questions
Will the result look different from the original?
Usually not noticeably. A file a little over 500 KB only needs its pictures re-saved at a high quality, which is invisible on screen. The more the file has to lose, the harsher the setting, and the status line says which one it used so you know when to check.
How many scanned pages fit in 500 KB?
Somewhere around five to ten at an ordinary scanning resolution, depending on how much of each page is picture and how dark it is. Typed pages are far smaller and are rarely the problem.
Is it better to choose 1 MB if the form allows it?
Yes. Always compress to the limit the form actually sets, or just under it: every step below that is quality given away for nothing. Compress to 1 MB opens on that size.
Is my PDF uploaded to do this?
No. It is read and rebuilt in this tab, by WebAssembly and your browser's own image encoder, and the page is served with a rule that forbids it from opening a connection anywhere. Turn the network off after the page loads and it works the same, which is the way to check rather than take it on trust.
What if it cannot get small enough?
It says so, with the smallest size it reached and why. Only the pictures inside a PDF can be squeezed; its text, fonts and structure are already compressed, so a file that is mostly those has a floor. Below that the way down is fewer pages: Split PDF takes out the ones the form does not need.
What 500 KB holds
| Contents | Under 500 KB? |
|---|---|
| A scanned form or contract, a few pages | Yes, with little visible change |
| A short report with photographs | Usually, at a medium setting |
| Receipts for an expense claim | Yes, several to a file |
| Twenty or more scanned pages | Hard; split it, or ask for a larger limit |
Other sizes
The same tool opened on another limit. Any of them will aim at any size once you are there.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.
This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.