Compress a PDF to 300 KB
For university portals, tender submissions and municipal e-services. The compressor searches quality settings until your file fits under 300 KB — and it runs on your own device, so nothing is uploaded.
The compressor is on the front page. Set your target and go — nothing is uploaded.
Open the compressorWhat 300 KB actually means in practice
300 KB sits in a comfortable middle. It is loose enough that a scanned document has room to breathe, and tight enough that an unprocessed phone photograph will still miss it. In practice a colour scan at 150 DPI lands close to this figure for a handful of pages.
If you are close but not under, the quickest win is almost always greyscale rather than harder compression — it removes two of the three colour channels at a stroke, and for black text on white paper you lose nothing that matters.
How to do it
- Open the compressor on the front page and choose your PDF.
- Leave the method on Target size.
- Type 300 into the target box.
- Press Compress. The tool tries progressively lower resolutions and quality levels, measuring the real output each time.
- Download the result. It is the best-looking version that still fits under 300 KB.
If you cannot get there
When the tool reports a smallest achievable size above your target, it has genuinely exhausted its options. Things that actually help, in rough order of effectiveness:
- Scan in greyscale or black and white. Colour scans carry three channels of data for documents that are almost entirely black text on white paper. This alone often halves the size.
- Crop the margins. Phone photographs of documents usually include a desk, a hand, and a lot of empty space, all of which cost bytes.
- Reduce the page count. Many forms ask for specific pages, not the entire document.
- Rescan at a sensible resolution. 600 DPI is for archival reproduction. 150 DPI is fine for a form upload and a quarter of the size.
Common questions
Can any PDF be compressed to 300 KB?
No. Every document has a floor below which it cannot go while remaining readable. 300 KB is realistic for five to eight text pages, or three to four scanned pages. Beyond that, the honest answer is to reduce the page count or scan in greyscale rather than to compress harder.
Will the text still be selectable?
Not in Target Size mode. Guaranteeing a hard byte ceiling requires rasterising the pages into images, which flattens the text layer. Lossless mode preserves selectable text but cannot promise a specific output size.
Is my document uploaded to a server?
No. Compression runs entirely in your browser. The file never leaves your device, and the tool keeps working if you disconnect from the internet after the page has loaded.
Why does the form still reject my 300 KB file?
Check whether the limit is stated in KB or KiB, and whether the form also restricts page dimensions or requires a specific PDF version. Some portals also reject files whose name contains spaces or non-English characters.