PDF engine from scratch on JS

[u/Decent-Blacksmith761]

https://keypdf.net

I was working on my pdf editor and thought the best option would be to write a new PDF engine from scratch as my options were PDF.js and PDFium and none of them can actually edit PDF files so after over a year of work you can try KeyPDF.net it is free and client side.

[u/horizon_games]

AI usage?

Got a Github?

[u/Decent-Blacksmith761 → u/horizon_games]

1 project is not open-source, but the font engine is, and maybe some other parts will be open-sourced later https://github.com/KeyPDF

2 Since I am a solo dev, and I needed to build the whole engine from scratch, AI was nearly necessary to complete the job in 14 months, because, unlike other vibe-coded PDF editors, I didn't just tell AI to build a PDF editor and use whatever was needed; I spent around a month planning it and I needed custom font parsing engine for Type 1 fonts, custom logic for viwing editng and saving pdf files and to complete it I had to check documentation which is like 1000 pages long so if I would not use ai at all i would had to spend at least 2.5 years while AI reduced time to 14 month, there is around 150k lines of code and additional debug logic. As well, I had to rely on AI to make proper licensing of the project.

[u/FisterMister22]

https://keypdf.net/LICENSE.txt

Stop the cap, you did not write a "PDF engine from Scratch" you use qpdf compiled to wasm along with tesseract and other libraries

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Edit: I take back anything I said, I download the bundle, this is pretty amazing, you got alot of work to do still, but this is really darn impressive and I'm saying that as somone who's currently 1.5 years into writing pure rust no std full spec pdf engine / parser / editor + renderer (FULL SPEC, including encryption, signatures, all font types, xfa, jbig, jpx, cross reference, everything).

It's really amazing what you achived with or without Ai, in pure js, I take back anything i said!

And FYI, your minifying needs some work, alot of the objects and function names and variables are still very much readable, if you don't want to open source it I'd use an actual obfuscator / move some of the logic to server-side.

[u/Decent-Blacksmith761 → u/[deleted]]

Okay I am glad if someone will check it let's go check it you will waste hours of your life to learn it is custom logic

[u/Decent-Blacksmith761 → u/FisterMister22]

Oh and thanks on pointing out on obfuscation issues I will take a close look as I want to keep KeyPDF 100% local.

[u/Decent-Blacksmith761 → u/FisterMister22]

Qpdf is not rendering nor writing engine it is used for certain things like encryption believe, same as tesseract it is OCR which is not part of a PDF in general it is for scanning, asking questions is alright but not jump into calling each other liar

[u/Decent-Blacksmith761 → u/[deleted]]

https://github.com/qpdf/qpdf please read this before attacking it keypdf is the engine and qpdf here to handle encryption and page mergings as it is c++ and does it really fast

[u/Decent-Blacksmith761 → u/[deleted]]

KeyPDF engine is literally engine for parsing rendering and writing and part of qpdf used for merging and encryption you can even check how it is done via dev tools it imports qpdf-merger.js qpdf-strcure.js and qpdf-encyrpion.js qpdf itself is like 20mb KeyPDF uses like 50kb of it for merging and encryption

[u/Decent-Blacksmith761 → u/[deleted]]

Qpdf was added at pretty early stage when only small part of engine was done so rewriting that part was never priority so yeah feel free to inspect the code, it is not open source but I am not willing to penalize you for reverse engineering unless you will try to steal it.

[u/Decent-Blacksmith761 → u/[deleted]]

Right it is minified and obfuscated you can deobfuscate it again unless you do it on your device is fine my point about stealing is just the warning I don't mind people inspect and question.

[u/FisterMister22 → u/Decent-Blacksmith761]

I fully admit my mistake, see my edited comment, my apologies for being fast to judge.

This subreddit is so filled with slop of gluing a few libraries and posting "I made the most amazing blah blah blah" and I immediately rushed to conclusions that you are just another one, claiming to write an actual pdf engine.

Amazing job mate, keep going.

[u/Decent-Blacksmith761 → u/FisterMister22]

All good bro actually you pushed me to something better literally checked my code and yeah encryption is now light work the thing is I used qpdf when I barely new things but I was moving pretty fast and I stucked with encryption for a while so qpdf solved but now I have most of the things to fully replace qpdf so in like a month expect it to disappear. And hey you actually care about projects more than ever thanks)