ICML File Format (.icml)

An ICML file is a single XML document holding one InDesign story's text and its paragraph and character style names, with no page geometry, meant to be opened in Adobe InCopy or imported into an existing InDesign layout rather than viewed on its own.

.icmlDocuments

ICML at a glance#

Full name	InDesign Markup Language
File extension	.icml
Category	Documents
Developer	Adobe
Compression	Uncompressed
FileFlip support	FileFlip writes this format but cannot open one

What a .icml file can hold#

These are the things a ICML file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Embedded metadata	No
Selectable text	Yes
Human readable	No
Schema or validation	No

Strengths and limitations of ICML#

What ICML does well

Carries paragraph and character styles as named tags, so a designer maps incoming text onto an existing InDesign stylesheet instead of restyling it by hand
A plain XML file, so it can be produced by a script without driving InDesign or InCopy directly
Lets a writer edit a story's text in InCopy while a designer works on the same page layout in InDesign at the same time

Where ICML falls short

Only Adobe's own applications open it; there is no independent viewer or general-purpose reader
Holds one story's styled text, not page geometry, so it can't stand in for a finished layout on its own
Adobe has never published ICML as an open standard, so its schema is documented only through Adobe's own developer material and can shift between InDesign versions

Use ICML to move styled text into an InDesign layout from a source that can generate structured XML, keeping paragraph and character styles intact instead of retyping the copy.

Convert content out of ICML once it leaves the InDesign workflow, since almost nothing outside Adobe's own applications reads it.

How to open a .icml file#

A .icml file opens in the programs below, grouped by the platform you are on.

Platform	Programs that open it
Windows	Adobe InDesign, Adobe InCopy
macOS	Adobe InDesign, Adobe InCopy

ICML questions people ask#

What application opens an ICML file?

Adobe InDesign and Adobe InCopy are effectively the only applications that open ICML files, since the format exists specifically to move a story's styled text between the two. There is no independent viewer for it outside Adobe's publishing tools.

What's the difference between ICML and IDML?

ICML holds a single story's text and style names with no page layout. IDML is Adobe's whole-document interchange format, introduced with InDesign CS4 in 2008, and includes complete page geometry alongside every story on it. Both are Adobe's own XML markup, but ICML is the narrower, InCopy-facing piece of that system.

Can I edit an ICML file as plain text?

Technically yes, since it's XML rather than a binary format, but hand-editing it risks breaking the story structure InDesign and InCopy expect. It's meant to be produced by InDesign's own export command and edited through InCopy's interface, not by typing directly into the markup.

Converting ICML files#

FileFlip cannot open a .icml file, so there is nothing to convert it into here. It appears on the site as something other formats can be converted to.

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.