PDF Medic OnlineCompress PDF to 50 KB
Make a PDF smaller than 50 KB for an upload form — the box below is already set.
Files never leave your device
How to Compress PDF to 50 KB
- Press Choose a PDF, or drop the file on the box above. Nothing is sent anywhere: the work happens in your browser.
- Check that Fit a size is picked and that Must be under (KB) says 48.
- Press Compress PDF and wait for the bar to fill.
- Look at the new size and zoom in on the pages. If both are fine, press Download.
What fits in 50 KB
Think of 50 KB as one scanned page, or a few typed ones. These results come from our own test files, so take them as a guide, not a promise.
- A short scanned letter, about ten lines on A4: 29 KB at Small. It fits with room to spare, at a sharper level than Smallest.
- A scanned A4 page about half full of text: about 44 KB at Smallest. It just fits.
- A full A4 page of small print, scanned in colour: about 84 KB even at Smallest. It does not fit.
- A page with one detailed camera photo: about 44 KB at Smallest. It just fits. Two such pages do not.
- A 3-page report with simple illustrations, 2.6 MB to start with: 42 KB at Small.
- Typed text: ten pages with a standard font came to about 26 KB, and this tool can’t make text smaller.
Which level you will probably get
With 48 in the box, a scanned page almost always ends at Small or Smallest. Small keeps up to 1300 pixels on a picture’s long side, about 110 pixels per inch on a full A4 page. Smallest keeps up to 900, about 75 per inch. The difference shows in small print, so look closely when the tool has gone all the way to Smallest.
Two scanned pages share the same 50 KB, so each gets about half. If the form lets you upload more than one file, put each page in its own PDF with Split PDF and compress them one by one: each page then has the full 50 KB to itself.
When 50 KB is the minimum
Forms often state a range, such as 50 KB to 300 KB. Then 50 KB is the floor, and the number to fit under is 300: use the Compress PDF to 300 KB page.
If Fit a size took your file below a minimum, start over and pick Best quality or Balanced instead. They shrink pictures less, so the file stays bigger, and still never bigger than your original. If the original itself is under the minimum, this tool cannot help: it only makes files smaller.
Why 48 and not 50
Here 1 KB is 1,024 bytes, so 48 in the box means 49,152 bytes. That is under 50,000, the limit on a site that counts 1 KB as 1,000 bytes, and under 51,200 on one that counts like we do. Typing 50 would mean 51,200 bytes, which the first kind of site would refuse.
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 50 KB?
Usually one scanned page with a moderate amount of text, or several typed pages. A page full of small print scanned in colour needed about 84 KB in our test, so it will not fit.
Can a PDF with a photo fit in 50 KB?
One photo page usually just fits: our detailed test photo came to about 44 KB at Smallest. Two photo pages will not. Simple pictures with large plain areas take less room than busy ones.
My file came out at 30 KB, but the form wants at least 50 KB. What now?
Press Start over, choose the same PDF and pick Balanced or Best quality instead of Fit a size. Check that the new size sits between the form’s minimum and maximum. If your original is already below the minimum, compressing cannot raise it.
Does compressing to 50 KB remove pages or words?
No. Every page and every word stays. Only the pictures inside the file are saved again with fewer pixels and a lower quality.
Is my file uploaded?
No. Compress PDF to 50 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.