Compress a PDF to 500KB

Five hundred kilobytes is the forgiving limit. Unlike the tighter caps, this one usually costs you nothing you would notice — provided the tool does not overshoot.

Files never leave your browser

Drop a PDF here or click to choose — already set to 500 KB

At this size the risk is the opposite one

On tight limits the danger is that the file will not fit. At 500 KB it almost always fits, and the danger becomes the tool being too eager: you ask for 500 KB, it returns 90 KB, and your certificate is suddenly a grey smear at full zoom.

That happens because most compressors do not aim at your number at all. They apply a fixed quality preset, and whatever comes out, comes out. If it happens to be far under the limit, they call it success.

Here the number is the target, not a ceiling to run away from. The tool climbs quality until it is about to exceed 500 KB, then stops one step short. A three-page scan that would fit at 120 KB comes back near 480 KB instead — the same document, considerably sharper, and equally acceptable to the form.

When 500KB is the right target to pick

Use it when the form's real limit is 500 KB, obviously — but also in two other situations where people wrongly reach for a smaller number.

When the limit is 1 MB or 2 MB. Set the target to the limit, not below it. There is no prize for a smaller file, and every kilobyte under the cap is detail you threw away.

When you are emailing scanned documents. Mail providers generally accept 20–25 MB per message, so a single 500 KB attachment is never the problem. Compressing to 500 KB keeps a folder of scans small enough to send together while staying readable on the other end.

What still changes, even at a comfortable size

One thing is true at every target and is worth repeating here, because at 500 KB the result looks so close to the original that it is easy to miss: the text in the finished PDF is an image. It cannot be selected, copied or searched.

For scans and photographed documents that costs nothing — the text was never selectable to begin with. For a PDF exported from Word, it is a genuine loss, and the better route is to export again from the original document with images downsampled, rather than compressing the finished PDF.

The tool says which resolution it settled on so you can check the result at full zoom before you upload it. And as with every tool here, the file is read from your disk, rebuilt in your device's memory, and handed straight back — it is never sent anywhere.

Nothing is uploaded, and you can prove it

The file is read from your disk, rebuilt in your device's memory, and handed straight back as a download. There is no server here doing the work, which is also why there is no daily limit, no account and no watermark.

That is not only a promise. This page is served with a Content Security Policy containing connect-src 'self', which instructs your browser to refuse any connection to another address. Open your browser's network tab and watch nothing leave — or load the page once, disconnect from the internet, and compress anyway. It still works.

Other PDF size limits

Set any other limit, quality or resolution on the main Compress PDF page, or read how upload size limits actually work.