Free · runs in your browser · the PDF is never uploaded
Compress a PDF to 300 KB
Short answer
Drop the PDF into the compressor below. It’s pre-set to 292 KB so the file passes a 300 KB limit however the site counts kilobytes. Two to three pages usually stay sharp at this size, and around ten plain pages fit at the lowest setting.
What fits in 300 KB
- Comfortably: Two to three pages at good quality, including a page with a photo.
- At the limit: Around ten plain pages at the lowest setting.
300 KB is a common ceiling for multi-page supporting documents, such as a set of mark sheets or a few months of payslips merged into one file.
If you’re merging several documents to meet one field, merge first and compress the result. Compressing each file separately and merging afterwards usually gives a bigger file.
“Good quality” here means around 100 DPI, which looks sharp on a screen. These are rough guides, not promises: a page of plain text compresses far better than a colour photo, so check the preview.
How to compress a PDF to 300 KB
- 1
Drop your PDF into the compressor above, or tap it to choose a file. It’s already in Target size mode at 292 KB.
- 2
Press Compress. A lossless rebuild runs first. If the file is still too big, the pages are re-rendered at lower resolutions, from 150 DPI down to 50 DPI, until it fits.
- 3
Check the preview of the first pages. Zoom in on the small print, such as dates, ID numbers and stamps, because that’s what blurs first.
- 4
Download the file and check its size on your device before uploading. On Windows, right-click and choose Properties; on a Mac, use Get Info. Compare the size in bytes with the limit.
- 5
Upload it. If the portal still says the file is too big, run the compressor again on the original with a slightly lower target.
Why the tool is set to 292 KB, not 300 KB
Kilobytes are counted two ways. Some websites treat 1 KB as 1,000 bytes; others, and this compressor, treat it as 1,024. A file the compressor calls “300 KB” is 307,200 bytes, about 2.4% more than 300,000, and a strict portal will reject it.
292 KB in the tool is 299,008 bytes, which is under 300 KB by either definition. You lose almost nothing in quality and avoid the most common “file too large” rejection.
If it won’t get down to 300 KB
The compressor stops at 50 DPI, because below that the text stops being readable. If even that pass is too big, you get the smallest readable file and a message saying so, instead of a file that technically fits but that nobody can read. These help:
- Merge, then compress. Combine the documents with Merge PDFs, then run the merged file through the compressor once.
- Put the important page first. Reviewers often only look at page one.
- Keep the original. Save the uncompressed file in case the portal later asks for a clearer copy.
- Split the document if the portal has more than one upload field. Split PDF breaks it into parts you can compress separately.
Limits worth knowing
- Re-rendered pages become images with an invisible text layer. Search and copy keep working, but accented and non-Latin characters can be dropped from that layer.
- Large or image-heavy PDFs take a while, because each pass re-renders every page on your device.
- Password-protected PDFs have to be unlocked first.
- A portal can reject a file for reasons other than size, such as the file type or characters in the file name.
Frequently asked questions
How do I get several documents into one 300 KB PDF?
Merge them into one PDF first, then compress the merged file to 292 KB. If it still won’t fit, remove pages that aren’t required or ask whether the portal accepts separate uploads.Will 300 KB be readable when printed?
For two or three pages, usually yes. If the compressor had to use its lowest settings to fit more pages, it will be fine on screen but soft when printed.Is my document uploaded when I compress it?
No. Everything runs in your browser and the file stays on your device.
Guides for upload limits
- PDFs for government formsFrom phone photo to a PDF that passes the portal’s size limit, plus what you can and can’t hide.
- Exam application documentsMake a reusable “upload kit” of your certificates at the sizes exam forms ask for.
- Job and onboarding documentsPayslips, certificates, relieving letters and ID for HR portals, sized and checked.
- Visa application documentsUnlock bank statements, merge by category and get each file under the upload limit.
- PDF upload size limitsTypical caps for email and portals — and how to shrink toward them privately.
Written by Sumit · Last reviewed 12 Oct 2026