pdfpix

Compress PDF to 150 KB

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

150 KB is 153,600 bytes. Government upload fields ask for it more than any other number between 100 and 200. The bench did not run a 150 KB target, so no hit rate on this page is measured for it. The two targets either side were measured, and they bracket what to expect.

How to compress a PDF to 150 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 150 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 to expect at 150 KB

The measured points either side are 23 of 56 at 100 KB and 18 of 38 at 200 KB. Reach rises as the cap loosens, so 150 KB sits between roughly 41% and 47% on that same mixed corpus. Your own file is not a corpus, and its kind matters far more than the average.

Scans met their target on 16 of 18 cases across the whole run. Text documents managed 10 of 50. A scanned form at 150 KB is a normal ask. A twelve page text report at 150 KB usually is not. The tool is free and caps nothing, so running it as a size reducer at 150 KB costs one attempt and tells you the answer for your own file.

What to drop first when 150 KB is close

Look at what the tool reports after a miss. If the winning method was font subsetting, the file is font heavy and the next saving is in removing pages, not in quality. If a page render won and stopped at its quality floor, the pages are photographic and there is nothing left to give.

Pages are the cheapest thing to cut. A cover sheet, a blank verso from a duplex scan, and a page of instructions the reader already has are often a third of the file. Removing pages before compressing changes the arithmetic more than any setting does.

Running it

Open the compress tool, choose the file, set the target to 150 KB and press Compress. Four methods race, every candidate is read back and checked, and you get the result with the method that won and the size it reached.

Nothing is uploaded. The file is read from disk into the tab, worked on there, and written back to your downloads folder. It is an online tool only in the sense that the page came from the web: the compression runs on your own machine. The 200 KB target is one chip away if the form turns out to be more generous than the label.

Questions

How many bytes is a 150 KB upload limit?
153,600 bytes at 1,024 bytes to the kilobyte, which is how the tool counts. A form counting in flat thousands stops at 150,000, a difference of 3,600 bytes. Target 145 KB if a file that looked like it fitted was refused.
Why is 150 KB so common on government forms?
The field was sized for one scanned page at a modest quality, and those limits are rarely revisited once a system is live. The number reflects storage per applicant rather than anything about the document you are sending.
My file stopped at 170 KB against a 150 KB target. What now?
You are one page or one quality step away. Remove any page the form does not need and run it again. If every page is required, rescanning the source in greyscale usually closes a gap that size on its own.
Does compressing to 150 KB remove the document metadata?
No. The title, author, subject and keywords are carried across to the output on purpose, so the compressed file says the same things about itself as the source did. If clearing those fields is what you actually want, use the privacy scan tool, which lists what the file carries before it strips anything.

The other pdfpix tools

All 30 of them run in a browser tab like this one. Each reads its own output back and checks it before offering the download, and none of them needs an account.

Where to go next