PDF Medic OnlineCompress PDF to 500 KB
Make a PDF smaller than 500 KB for an upload form — the box below is already set.
Files never leave your device
How to Compress PDF to 500 KB
- Press Choose a PDF, or drop it on the box above. If your papers are in several PDFs, join them first with Merge PDF.
- Fit a size is already selected, with 475 in Must be under (KB).
- Press Compress PDF. The file is worked on in your browser and never uploaded.
- Check the new size and a few pages, then press Download.
What fits in 500 KB
500 KB is room for a short set of documents rather than a single page. Our own test files gave these results; yours depend on what is on the pages.
- Full A4 pages of small print, scanned in colour: one page at Balanced (about 358 KB), two at Small (about 362 KB), or five at Smallest (about 417 KB).
- Pages with one detailed camera photo each: one page came to about 194 KB at Balanced, and three pages to about 279 KB at Small.
- Typed pages with no scans hardly count: ten of them came to about 26 KB.
Several papers in one upload
When a form asks for one file holding several papers, such as a certificate, a mark sheet and a letter, join them first with Merge PDF and compress the joined file here. Then the size check covers exactly the file you will upload.
If you compress each paper first and merge them afterwards, the merged file is roughly the sum of the parts, and you have to add the sizes up yourself. Compressing once at the end is simpler.
If the form accepts more than one file, you can also go the other way: split a long PDF into parts with Split PDF and compress each part under 500 KB. Each part then keeps more detail.
Why the result can be far below 500 KB
Fit a size tries four fixed levels, from Best quality down to Smallest, and keeps the first that fits. A 3-page photo report of 2.6 MB shows what that means: at Best quality it came to 680 KB, too big, so the tool took the next level, Balanced, at 128 KB. There is no step in between, so you get a file much smaller than you were allowed.
That file is still the best of the four that fits. If you would rather use more of the 500 KB, take a page or two out, or split the file as described above. The main Compress PDF page explains what each level does to pictures.
Why 475
This tool counts 1 KB as 1,024 bytes, so 475 means 486,400 bytes. A site that counts 1 KB as 1,000 bytes puts its 500 KB limit at 500,000 bytes, and 486,400 is safely under it. With 500 in the box, the file could reach 512,000 bytes and be refused there.
Everything happens in your browser: your file is never uploaded to any server. You can check: once your file is open, turn on airplane mode — the tool still works.
Questions
How many pages fit in 500 KB?
In our tests, five full pages of small print scanned in colour fitted at Smallest, two at Small, and one at Balanced. Pages with less on them, or typed pages, fit in larger numbers.
Should I compress each file before merging, or after?
After. Merge first with Merge PDF, then compress the one file here, so the size you see is the size you upload.
Why is my file only 128 KB when the limit is 500 KB?
The level above it was over 475 KB, and the tool has no step in between. It keeps the best of the four levels that fits, which can be much smaller than the limit.
Can I reduce a PDF to under 500 KB without installing a program?
Yes. This page works in any modern browser on a phone or computer. There is nothing to install and no account to make.
Is my file uploaded?
No. Compress PDF to 500 KB runs in your browser on your own device. The file is never sent to our server or anyone else. Once your file is open you can even turn on airplane mode.
Is it free?
Yes. No sign-up, no limits on how many files, and no watermark is added to your file.
Does it work on a phone?
Yes, in any modern browser on iPhone, Android, Mac, Windows or Linux. Very large files work best on a computer, because a phone browser has less memory.