Other PDF Editing Library

[stefnotch]

pdf-lib seems to be one of the few Javascript PDF editing libraries.

⭐ = worth investigating ❔ = unsure, might be a very difficult option ⛔ = blocked, doesn't work

Others that I've found after digging around even more

• ⭐ https://github.com/pmaupin/pdfrw is a low level library that was used to create https://github.com/osnr/horrifying-pdf-experiments
• ⭐ https://github.com/wcchoi/go-wasm-pdfcpu
  • https://pdfcpu.io/
• ⭐ https://github.com/andytango/mupdf-js
  • https://www.mupdf.com/product/ecosystem.html
  • https://www.mupdf.com/docs/examples/pdf-merge.js
  • https://github.com/julianfbeck/localpdfmerger
• ❔ Pdf.js can be used for low-level PDF editing, see https://github.com/DevelopingMagic/pdfassembler
  • https://www.pdfcircus.com/split-join
• ❔ https://github.com/jsscheller/qpdf-wasm proves that qpdf can be compiled to WASM
• ❔ https://github.com/manuels/unix-toolbox.js-poppler proves that some other PDF library can be converted to Javascript

If we decide to compile one ourselves with WebAssembly, options would include

• ❔ qpdf, mupdf, pdfcpu, libharu
• ⛔ Apache PDFBox: Blocked on https://github.com/mirkosertic/Bytecoder/issues/758 , basically Apache PDFBox has a dependency on freaking java.awt
• ⛔ PyPDF2: Blocked on https://github.com/brython-dev/brython/issues/1992 , basically it uses Python's built-in, native XML parser. Reimplementing that is impractical. Using Pyodide once its sleeker might be a decent option.
• ❔ PdfPig: Apache PDFBox, ported to C#

Interesting PDF debugging tool:

• https://github.com/itext/i7j-rups

Other sites:

• https://news.ycombinator.com/item?id=26323966
• https://shreevatsa.net/pdf-pages/ (same idea, way more primitive UI, has this interesting feature)
• https://pdftableutil.possiblenull.com/app/ (extracts text and tables from PDFs)
• https://parepdf.com/ (compares PDFs by overlaying them in red/blue)
• https://pdfux.com/merge-pdf/ (oha neat)

[stefnotch]

Btw, pdf-lib has this limitation atm: https://github.com/Hopding/pdf-lib/issues/341

[brennanyoung]

Just a FYI: Support for tagged PDF/UA is a deal breaker for some of us. This is an important criterion for judging the PDF authoring landscape.

Accessibility of documents is mandatory in the public sector, according to legislation in North America (USA/Canada), the EU, and various other jurisdictions. That's a lot of documents, and a lot of business.

Most PDF authoring tools don't do PDF/UA, or do it imperfectly.

Any tool which can help to automate the production of accessible PDF files has a chance to pull ahead of the pack.

AFAICT pdfkit is the only one that attempts to support PDF tagging, but I'd be delighted to learn about any others.

[stefnotch]

Good to know that I should take a close look at which libraries at least preserve that information.

pdfkit doesn't support editing an existing PDFs, so I'd need to use a different library if I want to edit an existing PDF document.