Remove all annotations from a PDF document

remove-annotations.sh

pdftk original.pdf output uncompressed.pdf uncompress
LANG=C sed -n '/^\/Annots/!p' uncompressed.pdf > stripped.pdf
pdftk stripped.pdf output final.pdf compress

Just for convenience for anyone finding this via google like me: This is the code to remove all annotations from all pdfs in a directory.

# these are needed on Mac
export LC_CTYPE=C
export LANG=C

# cd /directory/with/pdfs/

for file in *.pdf
do
    outname=`sed -e "s/\.pdf$/_.pdf/"<<<"$file"`
    pdftk $file output - uncompress | sed '/^\/Annots/d' | pdftk - output $outname compress
    echo "$file: done"
done

Is it possible to reduce the opacity?

this leave me with a PDF with a broken xref table :(

pdfcpu annotations remove my.pdf

works reasonably well :)
https://pdfcpu.io/annot/annot

Still works!