Export HTML5 or Publish online > export html5 package in CC2025

[Alam5EC6]

I am an InDesign Plugin developer and in the new release of InDesign CC 2025 I found a new feature which export a document as an HTML5 package using as follows

Export as an HTML5 or File > publish online > export html5 package

But I could not find any documentation in InDesign SDK or in scripting api how we could export a document as an HTML5 package.

Looking input either using scripting api or some service that we need to handle in sdk plugin

Any help here will be appreciated. 

[Alam5EC6]

I could not find a solution or documentation on HTML5 export - If someone has found anything then please share here

[Pickory]

Hi, not all the new shiny things made it to the SDK or the scripting world.

I suspect that you could do an ePub export and then expand the .epub package to access the HTML files for processing.

P.

[James Gifford—NitroPress]

Eh. I suspect that way lies madness. 🙂

[Pickory]

Eh? You reckon?

[James Gifford—NitroPress]

EPUB uses a limited and largely crippled variant of HTML — the now formally obsolete XHTML — and does not generally build content in web-conforming ways. I suppose you could get from ID -> EPUB -> Useful HTML/CSS, but even with very broad experience in all those areas, it ain't a road I'd take.

Not sure either PO or "HTML5 Export" are any better, given that they build pages in FXL mode, placing one digital mosaic tile at a time. The only export mode I've found useful is the now "Legacy HTML," which is imperfect but at least generates code you can repurpose.

[Pickory]

Would you like to offer a solution to the question?

[James Gifford—NitroPress]

I'm not a Script Guy™. 🙂

I'd suggest that manual export is not a difficult or time-consuming task and doesn't need to be scripted, at least until this oversight is corrected. (HTML5 export, in fact, bypasses all but one technical setting, so even export settings or a preset aren't needed.)

My entire focus was that EPUB is not any kind of good intermediate format for eventual HTML use, even if it does have a script hook.

[leo.r]

The entire Publish Online functionality has never been open to scripting (as far as I can tell), so not surprisingly HTML5 export (which is part of Publish Online) is not there either. 

[Dirk Becker]

There is a dedicated "InDesign developers prerelease" program in the prerelease site. Ask there. Maybe they're just behind on SDK + documentation or slashed them to cut hours until someone speaks up. Make sure you also mention scripting support.

In the meantime I would try some experiments first, if I had the time:

- add cheap plug-in based drawing, e.g. watermark via draw event. If it shows in the manually produced HTML5 package, you know that the service is local.

- even cheaper - pull the plug on your internet while performing an export. If it still works, it is local.

- set a few breakpoints and look around at the call stack. File requests to add headers to relevant facades to the SDK.

- if it is cloud based, watch out for obscure separate web service SDKs in the developer site.