Show HN: JavaScript-first, open-source WYSIWYG DOCX editor (github.com)

130 points by thisisjedr ↗ HN
We needed a JS-first WYSIWYG DOCX editor and couldn't find a solid OSS option, most were either commercial or abandoned.

As an experiment, we gave Claude Code the OOXML spec, a concrete editor architecture, and a Playwright-based test suite. The agent iterated in a (Ralph) loop over a few nights and produced a working editor from scratch.

Core text editing works today. Tables and images are functional but still incomplete. MIT licensed.

16 comments

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Ah these poor fools. Having built this exact product (OOXML compatible editor in React) before, it took all of two minutes to find a bug. The issue is that the OOXML spec is not in fact definitive - Word is, and trying to implement it from the spec will produce something that works maybe 80% of the time then fall over completely when you hit one of hundreds of minor, undocumented edge cases. Assuming of course that CC did not just hallucinate something. And then there's the more fundamental problem that HTML/CSS has unresolvable incompatibilities with OOXML. This is why Google Docs for instance use canvas for rendering.
When I saw the title I couldn't help but ask myself: how?

The spec is over 5000 pages long - no way in hell a human could parse this in a reasonable timeframe and no agent today has nearly the necessary context.

EDIT: also, like you said: the spec is secondary to the implementation and was only published (and not even in complete form originally!) because Microsoft was asked by the EU to do that.

Arent there any commercial libraries available already?

Somehow this reminds me of PDF

So it’s like Google Docs? What am I looking at exactly?
Whats a Ralph loop?
Excellent work! To put out the importance of the project - as of today there is not many google docs/word online alternative that is completely open source.

I'm yet to dig the code on how pagination is implemented but if the page breaks mimick word's - this is huge!

How far can Claude can take this beyond a cool demo.

Does it become exponentially harder to add the missing features or can you add everything else you need in another two days? I'm guessing the former but would be interested to see what happens.

Are you going to continue trying? I ask because it's only been two days and you're already on Show HN. It seems like if you waited for it to be more complete, it would have been more impressive.

Two very minor suggestions for the demo:

1. I don't know what the "Docxtemplater" button does, but it eats my document without warning and that's annoying.

2. It would be nice if the page came with some example .docx files we could see it work on.

Someone has to do it:

Please auto-ban any "We gave Claude/Gemini/Grok/OpenAO/Qwen/Mistral/WhateverLLMAI the spec and..."

"and..." resolves to:

- "and now we have this impressive result you won't believe!"

100% of the time this is attention seeking, live debugging - no value at all.

Don't waste people's time. Any sound and reasonable story about results without misusing the public's eye is welcome, for example:

- One year after - 10 hard problems we found - extensive pro/contra comparison with other solutions - maintaining such a AI app for one year

Otherwise: please auto-ban.

> As an experiment

The threshold for caring about experiments is exponentially higher in 2026 thanks to half baked vibe slop.

Non-functioning software and demoware comes fast and cheap, regardless of author.

> we gave Claude Code the OOXML spec

Having used the former a lot and read the latter in detail, uhhh…

Trim down the claims here, clarify the editor subset you plan to be supporting, and map the “last 90%”’s to honestly reflect the product you are pushing.

If “tables” and “images” aren’t there I’m quite skeptical about content controls and other key OOXML constructs being addressed meaningfully. The full OOXML footprint chokes OpenOffice out of procurements, rich OOXML documents choke half-way-there implementations (which was the whole point of the format).

As is pointed out elsewhere in the thread - there are fundamental constraints that have kept Google, Apple, and others from pursuing this route. Relatively simple docs are one thing, but OOXML is full of dragons and parity with Word has eluded more than a few tech giants.

There is HugeRTE, a fork of tinymce. I don't know how long they searched for a tinymce alternative
Thank you for sharing this and making it open source! I appreciate that when clicking the link you end up immediately in the tool. I saved it. This surely will be useful at some point.
Is there any good open source that actually work with web docx editing ?