Comparisons

IDML is one of many ways to capture a document — and the clearest way to see what it is for is to set it next to the others.

In short: Every document format makes a trade. A native binary is fast and exact but locked to one application; a PDF freezes a layout into fixed pixels you can print but not easily re-edit; HTML and CSS describe content that reflows forever; an office or structured-XML format captures meaning but leaves visual layout to the reader. IDML sits in a specific spot among all of these: an open, editable description of a fully composed paged layout. This section explains why that combination is unusual, how IDML differs from each neighbor, and when you'd reach for it instead. None of these formats is wrong — each is excellent at the job it was built for.

If you've read What paged media is and What IDML is, you already know the two ideas this section builds on: a page is a finite, fixed surface, and IDML describes a document's intent as readable XML rather than as rendered pixels. The natural next question is the comparative one. There are many formats a document could be stored in — so what does IDML give you that they don't, and what do they give you that it doesn't?

That question matters because choosing a format is choosing what you can do later. A format decides whether a document can still be edited or only viewed, whether its layout is preserved exactly or left to reflow, and whether anyone other than the original application can read and rewrite it. Pick the wrong one and you've quietly thrown away the option you needed most. So it's worth understanding the landscape before committing a layout to any single shape.

This section is conceptual — there are no IDML parts to dissect here. It's the map you consult before the detailed chapters, so that when later pages explain a story, a frame, or a style, you already know why IDML bothers to describe them the way it does rather than the way PDF or HTML would.

• IDML vs. other formats — fair, side-by-side comparisons with native binaries (INDD), fixed-form PDF, the web's HTML and CSS, and structure-only XML.
• Where IDML fits — when to reach for IDML rather than PDF or HTML, and how Paged turns it into real pages.

Frequently asked questions

Why compare IDML to other formats at all? Because the differences are exactly what make IDML useful. IDML's value isn't visible in isolation — it shows up when you notice that a native binary can't be read by other tools, that a PDF can't easily be re-edited, that HTML doesn't hold a fixed page, and that structure-only XML doesn't carry a finished layout. Seeing what each format gives up makes clear what IDML is preserving.

Is one of these formats better than the others? No. Each format is shaped by what it was built to do, and each is genuinely good at it: a native binary for fast in-application work, PDF for faithful final delivery, HTML and CSS for reflowing screens, structured XML for portable meaning. IDML is built for open, editable, fully-composed paged layout — a different job, not a better one. These pages compare honestly rather than crown a winner.

Which page should I read first? Start with IDML vs. other formats for the head-to-head differences, then read Where IDML fits for the practical question of when to choose IDML over a PDF or a web page.