Free · runs in your browser · the PDF is never uploaded
Compress a PDF to 30 KB
Short answer
Drop your PDF into the compressor below. It’s set to 29 KB so it passes a 30 KB limit either way the portal counts. One plain page is realistic; photos and busy colour scans often cannot fit and stay readable.
What fits in 30 KB
- Comfortably: One clean text or certificate page cropped to the document edges.
- At the limit: Rarely more than one page. Photo-heavy pages may hit the legibility floor.
30 KB sits between the ultra-tight 20 KB fields and the more common 50 KB caps on supporting-document uploads.
Expect the compressor to use a low DPI pass. Check seals and small type in the preview before you submit.
“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 30 KB
- 1
Drop your PDF into the compressor above, or tap it to choose a file. It’s already in Target size mode at 29 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 29 KB, not 30 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 “30 KB” is 30,720 bytes, about 2.4% more than 30,000, and a strict portal will reject it.
29 KB in the tool is 29,696 bytes, which is under 30 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 30 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:
- Crop first with Crop pages so table edges and shadows are not in the frame.
- One page only — delete extras with Delete pages.
- Rescan in black and white if the phone photo is grey and soft.
- 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 compress a PDF to 30 KB?
Use this page. The tool is pre-set to 29 KB, tries a lossless pass first, then lowers resolution until the file fits or hits the readable floor.Why 29 KB instead of 30 KB?
Some portals count 1 KB as 1,000 bytes. 29 KB in the tool stays under 30,000 bytes either way.Does this upload my file?
No. Compression runs in your browser.
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