What this IDML preflight checks
The inspector validates ZIP boundaries, entry paths, CRC-32 evidence, the exact leading uncompressed mimetype, META-INF/container.xml, and designmap.xml. It follows design-map component paths, checks the standard Fonts, Styles, Graphic, and Preferences resources, parses bounded XML parts without DTD expansion, inventories document content, and reports malformed, missing, unlisted, duplicated, case-mismatched, or unsafe members.
Dependencies and identifiers
Every parsed Self definition is indexed across the package. The dependency audit resolves high-value references such as ParentStory, AppliedMaster, paragraph, character, object, cell and table styles, color references, and font names. It also reconciles the Document StoryList with actual story parts and counts the text frames hosting each story.
Comparing two exports
The optional comparison matches stories, spreads, links, fonts, and styles using their IDs or stable names, then compares meaningful inventory summaries. It separately reports package entry changes using paths, sizes, and CRC values. This avoids pretending that ordinary ZIP ordering or compression differences are layout changes while still exposing altered component bytes.
Important preflight boundary
This is a bounded structural diagnostic, not Adobe InDesign, a complete IDML schema validator, or a visual rendering comparison. It does not render pages, prove fonts or links exist on another workstation, validate every DOM object and enumerated value, execute plug-in data, resolve operating-system aliases, compare visual appearance, repair packages, or guarantee that InDesign will open or reproduce the document identically. Confirm deliverables in the intended InDesign version and run the organization’s normal print-production checks.
Frequently asked questions
Does this upload publication text or asset paths?
No. ZIP expansion, XML scanning, reference checks, comparison, and exports run locally in the browser.
Why is a file: link not automatically an error?
IDML commonly records the original external location of a placed asset. Browser security prevents this page from checking that workstation path, so the URI and declared link state are shown without inventing an availability result.
Does a clean report mean the layout is unchanged?
No. The comparison exposes structural and inventory differences, but typography, reflow, color management, transparency, plug-ins, and rendering require InDesign and visual review.
Authoritative references
The Adobe IDML File Format Specification defines the UCF package, design map, components, object identifiers, resources, and XML vocabulary. Adobe’s current InDesign ExportFormat reference identifies IDML as InDesign Markup output.
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