Compress PDF to 150 KB

Between the 100 and 200 KB limits, and often the one for a single certificate or a short scan. 150 KB is typed in already.

Free to use
Works on any device
Deleted after processing

Text stays vector-sharp
Sized for email
Every page kept
The original is untouched

PDF

Make your PDF 150 KB or smaller

Text stays sharp at every level · your upload is deleted as soon as the smaller file is built

Drag & drop file here

or choose a file from your device

How it works

Compress PDF to 150 KB in three steps

Add the PDF

One document per file works best at this size: a certificate, a mark sheet or a signed form.

150 KB is already typed in

The "To a size" option is already on, with 150 in the size box. Change it only if your form gives a different number.

Zoom in, then download

Open the result and look at the smallest print at full size before you upload it.

150 KB on our test files

The same seven files as our 400 KB test, on the 150 KB setting. Measured on October 31, 2026.

Test file	Before	After	Page DPI after	How it looks
Typed letter, 2 pages	3 KB	3 KB	No pictures	Unchanged
Report, 4 pages with 3 photos	842 KB	145 KB	110	Photos good on screen
Report, 8 pages with 6 photos	1.86 MB	134 KB	72	Text sharp; photos fine on screen
Scanned letter, 1 page, color	1.33 MB	123 KB	150	Close to the original
Scanned letter, 2 pages, color	2.66 MB	80 KB	72	Readable; small print soft
Scanned report, 3 pages, grayscale	4.94 MB	127 KB	72	Readable; small print soft
Scanned report, 10 pages, grayscale	14.8 MB	123 KB	50	Words readable on screen; small print hard

The two page color scan is the one to learn from: at 110 DPI it was 150.9 KB, less than 1 KB over, so it went down a whole step. A slightly higher limit, or one page fewer, keeps the sharper version.

Getting a certificate under 150 KB and still readable

Most of the work happens before the PDF is made:

Crop the photo to the edge of the paper. The table or bed around a phone photo costs space and looks poor.
One document, one file. A certificate and a mark sheet in one PDF have to share the 150 KB.
Look at the smallest print at full size on the result before you upload it.

Frequently asked questions about Compress PDF to 150 KB

What fits in 150 KB?

One scanned page in color at the full 150 DPI (ours came to 123 KB), two or three scanned pages at 72 DPI, or a short typed report with a few photos: our four page report with three photos fitted at 145 KB, photos at 110 DPI.

My two page scan came out at 80 KB. Why so far under 150 KB?

The tool tries fixed steps of sharpness and keeps the first one that fits. Our two page color scan was 150.9 KB at 110 DPI, just over the line, so it went down to the next step, 72 DPI, at 80 KB. If your form counts a KB as 1,024 bytes, its 150 KB limit is really 153,600 bytes, and typing 153 in the size box keeps the sharper step. If you are not sure how it counts, leave 150.

Can a ten page scan get under 150 KB?

Ours did, at 123 KB, but only at 50 DPI: the words read on a screen, while small print is hard to make out. If the form takes several files, split it with Split PDF and upload the parts. If it wants one file, take out the pages you do not need with Organize PDF first.

Will a signature or a stamp still show?

At 150 or 110 DPI they stay clear. At 72 DPI a stamp is still visible, but the fine lines of a signature soften. If they matter, keep the document to one or two pages so it can stay at a higher step.

Does compressing change the text?

Typed text is not a picture, so it stays sharp and searchable at any size. Only scans and photos lose detail.

Full step-by-step guide

All PDF tools · 15 step-by-step guides · How your files are handled

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