Compress PDF to KB: Reduce Your PDF to an Exact File Size
Compress PDF to KB when a form will not take a file that is still in megabytes. One file, up to 50 MB and 30 pages. Strong mode hits an exact KB target.
Your files never leave your device. Compression runs entirely inside your browser using your phone or computer's own processor. Nothing is uploaded to a server, nothing is stored, and the page keeps working even if you go offline after it loads. Re-encoding a photo builds a new file from pixels, so camera metadata such as GPS is removed. Read the privacy policy.
How to reduce a PDF from MB to KB
- Choose one PDF. Files over 50 MB (50,000,000 bytes) or over 30 pages are refused so a phone does not run out of memory.
- Set 100, 200, 300, 500 KB, or your own number. Tap a page thumbnail to leave that page out.
- Compress, read the before and after sizes, and download
name-200kb.pdf. Strong mode warns you that the text is now a picture.
A 10-page scan can be several megabytes because each page is already a photograph of paper. The target is shared across the pages you keep. At 200 KB, ten pages have about 20 KB each before the PDF wrapper. That is enough for a readable scan of a certificate, not for a poster.
Two ways to shrink a PDF
Light: keep text selectable
Light mode rebuilds the PDF with tighter object streams and the pages you kept. Words stay selectable and searchable. Links and form fields that were in those pages stay if the file format allows it. The file often shrinks only a little. If it misses the KB target, the result tells you to switch to strong mode. Use light mode when you still need to copy a sentence out of the document.
Strong: hit an exact KB target
Strong mode is the default because most KB limits are exact. Each kept page is drawn, saved as a JPEG, and placed on a new page of the same size. The search tries a few drawing sizes and JPEG qualities until the finished PDF is at or under the byte ceiling. Text cannot be selected or searched. Links, bookmarks, and form fields are removed. The result card repeats that warning so you do not upload a picture-PDF where a form expected live text.
Tips for scanned certificates and mark sheets
A scan is already a picture, so strong mode matches it. Turn on grayscale when the page is ink on paper. Color spends bytes on the shade of the sheet. Delete blank pages before you compress. Cropping is not offered here; if the scan has a huge empty border, export a tighter PDF from the scanner first, then come back.
Password-protected files are refused. Remove the password in the app that created the PDF. This page does not guess passwords and does not send the file out to be unlocked. A single photo, rather than a PDF, belongs on the image tool. A handwritten signature belongs on the signature resizer.
Your privacy
Your files never leave your device. Compression runs entirely inside your browser using your phone or computer's own processor. Nothing is uploaded to a server, nothing is stored, and the page keeps working even if you go offline after it loads. Re-encoding a photo builds a new file from pixels, so camera metadata such as GPS is removed. Read the privacy policy.
The PDF engine downloads the first time you choose a file, then stays on this device. After that you can disconnect and compress. If you are already offline and it has never loaded here, connect once and choose the file again. Page text is not sent to analytics.
Frequently asked questions
How do I get a PDF under a KB limit?
Type the limit from the form, such as 100, 200, or 500, and press Compress PDF. Strong mode redraws each page so the new file can land at or under that many thousands of bytes.
Will strong mode delete my text?
Strong mode redraws every page as a picture, then builds a new PDF. The words still look the same, but you cannot select them, search them, or copy them.
Links, bookmarks, and form fields are dropped because they do not survive that redraw. Use strong mode when the form only cares about the KB size and a readable scan.
Light mode keeps the original text selectable. It often cannot hit a small KB target. If it misses, the page tells you to switch to strong mode.
Why can a long PDF not reach a very small KB size?
The target is shared across every page you keep. A 200 KB limit on 10 pages is about 20 KB per page before the PDF wrapper.
At that budget each page has to be a small, lower-quality picture. Text becomes harder to read if you push further.
Delete blank pages first, then raise the target if the scan is still soft. Thirty pages and 50 MB are the ceilings here, so a phone does not run out of memory.
Can I compress a password-protected PDF?
No. The page detects the password and stops. It does not guess passwords and it does not send the file anywhere to be unlocked.
Remove the password in the app that created the PDF, save a copy you are allowed to edit, and open that copy here.
If the file is not actually a PDF, you will get a different message asking you to export it again.
Is the PDF uploaded?
No. The file is read in your browser, the same way a photo is. Closing the tab drops it. There is no account and no stored copy on a server.
The engine downloads the first time you choose a PDF. After that, you can turn the network off and still compress. If it has never loaded on this device, connect once and choose the file again.
Do not compress a PDF you are not allowed to change. The size limit on a form is not permission to alter someone else’s document.
Will this work on a phone?
Yes, within the limits above. A short scanned certificate is a normal job for a phone browser.
Very large drawings or dozens of photo pages can still fail if the phone runs out of memory. The page shows an error instead of a broken download.
Use the grayscale switch on scans of stamps and text. Color scans spend bytes on paper tone you may not need.