pdfpix

Compress PDF to 300 KB

or drop one here
Compression level
Target size
Choose a PDF file first.

300 KB is 307,200 bytes. It holds 20 text pages, 8 pages with pictures, 10 scanned pages, 16 phone photos of pages or 11 pages scanned in colour. A ten page scanned certificate pack or a twenty page typed report fits. Type 300, press Compress, and the result shows its exact size.

How to compress a PDF to 300 KB

  1. Choose the PDF

    Press Choose a PDF, or drop the file on the page. The file is read in this tab and is not sent anywhere.

  2. The target is already set

    This page opens at 300 KB, so there is nothing to type. Pick a different level, or enter your own smaller number in KB, if you want another size.

  3. Press Compress

    Four methods race: copy the pages into a fresh file, re-encode the placed images, cut each embedded font down to the glyphs the pages draw, and, only when no other method reached the target, redraw the pages as images with the text kept on top.

  4. Read the check, then download

    Every candidate is opened again and its characters are counted against the source. The page shows the size, the method that won and the characters kept before it offers the download.

The four methods are described in full, with the measurements behind them, in how it works.

What 300 KB holds

A scanned page came down to about 29 KB in the public run, so 300 KB holds a 10 page scan. A text page came down to about 14 KB, so a 20 page report fits.

DocumentPages at the default settingPages at the smallest setting
Text documentsPages at the default setting20Pages at the smallest setting20
Text with picturesPages at the default setting7Pages at the smallest setting8
Scanned pagesPages at the default setting10Pages at the smallest setting10
Phone photosPages at the default setting4Pages at the smallest setting16
Colour scansPages at the default setting3Pages at the smallest setting11

A worked example at 300 KB

A 2 page colour scan of a US federal record went from 1.7 MB to 267 KB by redrawing the pages as 150 dpi images with the text kept on top. On the public files above 300 KB, the default methods cut the median file by 81.1%.

The result names the method that won. If it was the structural rebuild or font subsetting, no pixel changed.

Longer scans at 300 KB

Divide the cap by the pages. If the form takes more than one file, split the scan and upload the parts. Each part gets the whole budget.

200 KB and 400 KB are the nearest targets.

Questions

How many bytes is a 300 KB limit?
307,200 bytes at 1,024 bytes to the kilobyte, which is how this tool counts. A form that counts in thousands stops at 300,000, 7,200 bytes tighter. Set 292 KB if a file was refused once.
Is 300 KB enough for a scanned certificate?
Yes. A scanned page came down to about 29 KB in the public run, so 300 KB holds a certificate of up to 10 pages.
Is there a free pdf compressor to 300kb that keeps the text?
This one is free, with no account needed, and it verifies the text. Every output is read again and must keep 98% of the source's non-space characters, or it is refused.
Should I compress a long scan or split it?
Split it if the form takes several files. Each part then gets the whole budget, and the pages keep more detail.

Related tools

Each runs in a browser tab like this one, reads its own output back before the download, and needs no account. The footer links every tool.

Where to go next