PDF-Diff
Dev tools
pdf comparison tool
SHOW HN2022
169points
36comments
#356of 2,570 in 2022
Top 14%of 2022 by points
How HN took it
CuriousMostly questions and neutral comments
4 positive, 12 neutral or asking, 0 mixed, 2 critical, out of 18 comments about the project. Thread score +0.09.
Idea: 4 for, 0 againstExecution: 0 for, 2 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Useful for spotting differences in books and schematics
From 2 comments
I made a PDF diff tool for myself for one of my internships >10 years ago. One of my responsibilities was to get sign-off on any changes engineers made to schematics. (It was a…
rcfox on HN> After the first few times comparing PDFs of schematics by eye, I said screw it and wrote a tool to export to PNGs and then compare them pixel-by-pixel. It saved me a ton of…
crecker on HN
Rasterizing before comparing is a clever approach
From 1 comment
Rasterization prior to comparison is a really clever idea. Doing this with PDF spec code would be an absolute nightmare. Checking 2 bitmaps for equality is just a few lines of…
bob1029 on HN
Objections
Page shifts cause every following page to show as different
From 2 comments
Aha. If one paragraph is added on page 1, it might show a diff on every following page in the same chapter after that, if it causes things to shift? It's not easy to decide when…
kzrdude on HNImageMagick's `compare` can do this as well, on a pixel-level. The issue is that in some cases, for example when the change is that a long sentence has been inserted in the…
mr_mitm on HN
Requests
Ignore page boundaries so shifts do not cascade
From 2 comments
Most important for me is the ability to ignore page boundaries. Removing the first half of the first page of one source document shouldn't produce differences on all following…
dloss on HNIt's automatic. As if there were no page boundaries, like in text diffs). But for a paged-based diff-tool it would already be quite useful, if the user could interactively…
dloss on HN
Interactive visual tool with page ignoring
From 2 comments
> It's automatic. As if there were no page boundaries, like in text diffs). But for a paged-based diff-tool it would already be quite useful, if the user could interactively…
crecker on HNIt's automatic. As if there were no page boundaries, like in text diffs). But for a paged-based diff-tool it would already be quite useful, if the user could interactively…
dloss on HN
Questions
Does it use OCR for comparison?
From 1 comment
Do you compare via OCR?
avipars on HN
Alternatives named
diff-pdf
From 1 comment
See also diff-pdf https://vslavik.github.io/diff-pdf/ that I usually use for this. (Seems to be relatively popular; 1.4k stars on GitHub: https://github.com/vslavik/diff-pdf)
svat on HN
DiffPDF
From 2 comments
On Windows I was quite happy with DiffPDF[1]. As far as I remember there used to be an older open source version as well. But I could not found it on first glance. [1]…
smartmic on HNThat would be http://www.qtrac.eu/diffpdf-foss.html There is a fork here: https://gitlab.com/eang/diffpdf
kondyt on HN
Draftable
From 1 comment
https://draftable.com is my go-to tool in this space. It understands text flow and the difference between structural and formatting differences, and is amazing when given PDFs of…
btown on HN
i-net PDFC
From 1 comment
i-net PDFC is my favorite tool in this space (after having tried a dozen others). Awesome features, multi-platform. Free trial version and an online demo available.…
dloss on HN
Beyond Compare
From 1 comment
I just use Beyond Compare from Scooter Software. Best program ever. Been using it for 20 years now. I swear by it as an evangelist user. Diff images, Excel documents, PDFs,…
JakeAl on HN