How do I reduce the size of a pdf file that contains images?

Question

I have a pdf file that contains images and I want to reduce its size in order to upload it to a site with a size limit.

So, how can I reduce the size of a pdf file from the command-line?

by "images" probably you mean "raster images" but PDF files can also contain vector images, which [can be really large](https://community.adobe.com/t5/acrobat-discussions/pdf-size-is-content-stream-the-problem/m-p/2286382), and which are harder to compress, see also [Replacing vector images in a PDF with raster images](https://tex.stackexchange.com/questions/47076/replacing-vector-images-in-a-pdf-with-raster-images) — milahu, Aug 21 '23 at 17:39

Pandya · Accepted Answer · 2023-05-11T08:46:24.640

63

You can use gs - GhostScript (PostScript and PDF language interpreter and previewer) as follows:

Set pdfwrite as output device by -sDEVICE=pdfwrite
Use the appropriate -dPDFSETTINGS.

From Documentation:

-dPDFSETTINGS=configuration
Presets the "distiller parameters" to one of four predefined settings:

/screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.

/ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.

/printer selects output similar to the Acrobat Distiller "Print Optimized" setting.

/prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.

/default selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file.

-o option to output file which also set -dNOPAUSE and -dBATCH (see Interaction-related parameters)

Example:

$ du -h file.pdf 
27M file.pdf

$ gs -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -q -o output.pdf file.pdf

$ du -h output.pdf 
900K    output.pdf

Here -q suppress normal startup messages, and also do the equivalent of -dQUIET which suppresses routine information comments

edited May 11 '23 at 08:46

answered Apr 05 '16 at 12:53

Pandya

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Doesn't work for me. A searchable PDF output by `tesseract` remains completely unchanged when attempting to shrink it with this command. – Gabriel Staples Dec 30 '19 at 17:44
We can also use `-compress jpeg -quality 50` type of workaround (additionally `-resize 75%`) with `convert` command. – Pandya May 23 '20 at 10:50
do you often talk to yourself? :-D – Student Dec 09 '20 at 10:36
@Student Didn't understand – Pandya Dec 09 '20 at 12:23
@Pandya you can edit your answer instead of commenting – Rainb Mar 31 '21 at 07:32
@Student was probably wondering the reason for asking a question at 5'16 12:53 and answering it yourself at 5'16 12:53. :-) – cheems Jun 30 '21 at 10:25
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@OldMan It was share QA mode – Pandya Jun 30 '21 at 18:00
Wow, finally, a solution to this problem. – polynomial_donut Jul 25 '22 at 10:52
If your current pdf page size is large, you might also need to shrink it down to normal A4 size with addional options `-sPAPERSIZE=a4 -dPDFFitPage` because `/ebook` etc. only shrinks it according to page size – phil294 Mar 17 '23 at 03:43
those documentation links are broken. – starbeamrainbowlabs May 08 '23 at 19:29
@starbeamrainbowlabs Check the updated links :) – Pandya May 11 '23 at 08:50

score 12 · Answer 2 · answered Nov 03 '18 at 14:27

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ps2pdf input.pdf output.pdf

I got the answer from ask ubuntu and it worked for me. It actually reduced 18.1Mb to 1.0Mb

answered Nov 03 '18 at 14:27

Freeman

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Doesn't work for me. A searchable PDF output by `tesseract` remains completely unchanged when attempting to shrink it with this command. – Gabriel Staples Dec 30 '19 at 17:46
This is awesomely simple if you don't care to choose all the options that GhostScript needs. The man pages say that the script accepts the same parameters as `gs`, it gives this example: `ps2pdf -dPDFSETTINGS=/prepress figure.ps proof.pdf` – Cris Luengo Apr 28 '20 at 23:11

score 2 · Answer 3 · answered Jun 20 '23 at 12:12

If the PDF file consists entirely of image data;

pdftk inputFile.pdf burst
mogrify -density 300 -format jpg -quality 20 pg_*.pdf 
convert *.jpg -auto-orient outputFile.pdf

The density value can match the density of the source image (eg 300 dpi), but the jpeg quality should be lower than the source image (e.g. 20).

score 1 · Answer 4 · answered Aug 09 '18 at 16:01

You can try this :

$ time pdftk myFile.pdf output myFile__SMALLER.pdf compress
GC Warning: Repeated allocation of very large block (appr. size 16764928):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 8384512):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 11837440):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 8384512):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 33525760):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 7254016):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 34041856):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 33525760):
    May lead to memory leak and poor performance.

real    0m23.677s
user    0m23.142s
sys     0m0.540s
$ du myFile*.pdf
108M    myFile.pdf
74M     myFile__SMALLER.pdf

It is faster than gs but compresses upto 30% in this case for a 107.5MiB input file.

Doesn't work for me. A searchable PDF output by `tesseract` remains completely unchanged when attempting to shrink it with this command. — Gabriel Staples, Dec 30 '19 at 17:47
This only restores the regular PDF page stream compression if the file happens to be in uncompressed (textual) format. Won't do much usually. — Michel de Ruiter, Jan 23 '22 at 19:27

How do I reduce the size of a pdf file that contains images?

4 Answers4