I do a lot of backend document (docx file) generation work, and updating our templates and backend code is one of my least favorite development tasks. Cryptic errors, minute-plus rebuild loops. I’d much prefer building these reports in JS rendered HTML (e.g., Vue or React), but existing HTML-to-docx libraries in the OSS ecosystem don't produce output that's actually valid, editable Word structure.
I'd had good luck applying Karpathy's Autoresearch pattern (agent runs iterations against an objective score, keeps what improves, discards what doesn't) to a couple of other problems, and figured OOXML fidelity was a good fit.
The Autoresearch process goes like this: render HTML and take a screenshot, use dom-docx to convert to docx, rasterize the docx file with LibreOffice and take another screenshot, score the browser HTML screenshot vs LibreOffice screenshot and measure layout fidelity + editability + speed as a quality metric, feed score back in, and repeat to drive higher fidelity within the constraints of editability and performance. It’s a beautiful thing to watch.
Burned some tokens and ran that loop against 37 real-world HTML patterns such as nested lists, tables, flex layouts and blockquotes (stuff that often breaks converters) and "brute forced" my way to what I hope is a high-fidelity HTML to docx converter.
A few things about where it landed:
- Native OOXML output, real Word structure, not a screenshot or a 1x1 table pretending to be a document
- Works in Node, in the browser (no Playwright needed for the default path), and as a CLI (npx dom-docx input.html -o output.docx)
- MIT licensed
- Full benchmark methodology + results vs the established OSS alternatives: https://github.com/floodtide/dom-docx/blob/main/docs/BENCHMA...
Live demo if you want to test HTML conversion in the browser: https://dom-docx.com
Happy to answer anything about the scoring loop or anything else.
PS: This is the first thing I've open sourced and I'm excited to see where it leads!
show comments
ape4
Just adding, since I don't see it mentioned in the readme, that its written in Typescript. That's what makes this interesting. I imagine Pandoc can do this but its not Typescript (its Haskell).
show comments
jkwang
The screenshot-to-docx scoring loop is a clever way to verify layout fidelity. Very useful for anyone generating reports from HTML.
show comments
conwy
Awesome, thanks so much for open-sourcing!
Will use it to generate my C.V. in Word format.
rkagerer
I'd be thrilled if this could lead to higher fidelity print and Save-to-PDF functionality in browsers.
noufalibrahim
Surely I can't be the only one who misread the heading and clicked expecting to see DOOM implemented using just HTML DOM. :-/
show comments
eagleinparadise
Can this go docx -> html -> docx?
show comments
virajk_31
I have done something similar for PPTX, keeping the fidility intact was really challenging with computed values & OOXML counterparts and again challanges with different XML implementations like that of MS & Libre..
show comments
topaztee
this is cool.
I'm curious how many tokens ($) it cost you to build?
i'm also building in this space (an MCP for agents to manipulate docx)
show comments
jrm4
Good work on the effort to the author.
And every time y'all, how absurd is it that this still has to exist? It never stops being wild to me.
Hey HN, author here.
I do a lot of backend document (docx file) generation work, and updating our templates and backend code is one of my least favorite development tasks. Cryptic errors, minute-plus rebuild loops. I’d much prefer building these reports in JS rendered HTML (e.g., Vue or React), but existing HTML-to-docx libraries in the OSS ecosystem don't produce output that's actually valid, editable Word structure.
I'd had good luck applying Karpathy's Autoresearch pattern (agent runs iterations against an objective score, keeps what improves, discards what doesn't) to a couple of other problems, and figured OOXML fidelity was a good fit.
The Autoresearch process goes like this: render HTML and take a screenshot, use dom-docx to convert to docx, rasterize the docx file with LibreOffice and take another screenshot, score the browser HTML screenshot vs LibreOffice screenshot and measure layout fidelity + editability + speed as a quality metric, feed score back in, and repeat to drive higher fidelity within the constraints of editability and performance. It’s a beautiful thing to watch.
Burned some tokens and ran that loop against 37 real-world HTML patterns such as nested lists, tables, flex layouts and blockquotes (stuff that often breaks converters) and "brute forced" my way to what I hope is a high-fidelity HTML to docx converter.
A few things about where it landed:
- Native OOXML output, real Word structure, not a screenshot or a 1x1 table pretending to be a document - Works in Node, in the browser (no Playwright needed for the default path), and as a CLI (npx dom-docx input.html -o output.docx) - MIT licensed - Full benchmark methodology + results vs the established OSS alternatives: https://github.com/floodtide/dom-docx/blob/main/docs/BENCHMA...
Live demo if you want to test HTML conversion in the browser: https://dom-docx.com
Happy to answer anything about the scoring loop or anything else.
PS: This is the first thing I've open sourced and I'm excited to see where it leads!
Just adding, since I don't see it mentioned in the readme, that its written in Typescript. That's what makes this interesting. I imagine Pandoc can do this but its not Typescript (its Haskell).
The screenshot-to-docx scoring loop is a clever way to verify layout fidelity. Very useful for anyone generating reports from HTML.
Awesome, thanks so much for open-sourcing! Will use it to generate my C.V. in Word format.
I'd be thrilled if this could lead to higher fidelity print and Save-to-PDF functionality in browsers.
Surely I can't be the only one who misread the heading and clicked expecting to see DOOM implemented using just HTML DOM. :-/
Can this go docx -> html -> docx?
I have done something similar for PPTX, keeping the fidility intact was really challenging with computed values & OOXML counterparts and again challanges with different XML implementations like that of MS & Libre..
this is cool. I'm curious how many tokens ($) it cost you to build?
i'm also building in this space (an MCP for agents to manipulate docx)
Good work on the effort to the author.
And every time y'all, how absurd is it that this still has to exist? It never stops being wild to me.