How to open an IDML file without InDesign

You can open an IDML file without InDesign by loading it into Design, the page layout app in Madosuite, which runs in a browser tab for free. Design opens .idml files, and it can export them to PDF or EPUB once you have checked the pages.

One thing first: Design is pre-alpha. It opens IDML, but you should check every page before you rely on the result. More on that under “What may not carry over”.

What an IDML file is

IDML is the file InDesign writes when someone chooses to share a layout in an open format. It is a zip archive of XML files. You can unzip it and read the text, but unzipping does not show you the layout: the frames, columns, styles and page positions only make sense in a layout app.

That is why people send IDML instead of INDD. It is easier for other programs to read. If you were sent an .indd file instead, Design can import that too.

Open the IDML file

Go to the Madosuite desktop. No account is needed.
Open the Store and add Design. It takes one click.
Open Files, press Upload and pick your .idml file.
Open the file with Design.

The file goes into the home folder of the Linux machine that Madosuite runs in your browser, on your own device. It is not uploaded to us. Note that clearing the site’s data in your browser deletes the files in that folder, so keep your own copy of anything important.

Check the layout

Design is built around the same ideas as other layout apps: spreads, parent (master) pages, layers, text frames, threaded text across columns, paragraph and character styles, tables, text wrap and named swatches, including CMYK process colours. Walk through the document with those in mind:

Page through every spread. Look for text that has moved to the next frame or page.
Check that threaded stories still flow in the right order across columns.
Look at headings and body text. If the paragraph and character styles came through, the type should match the original’s look.
Check the swatches. Named colours and CMYK process colours should be listed by name.
If the sender also gave you a PDF of the layout, put the two side by side. Fonts are the most common place where a layout shifts, because a missing font changes line breaks.

If you only need to read the document, you can stop here. If you need to change it, edit the text and frames in Design, then save.

Export to PDF or EPUB

Design can save and export the document in these formats:

PDF, as PDF/X-4 or PDF/A-2b. Line breaks in the PDF are the same as on screen.
EPUB, for an e-book version.
IDML, if you need to send it back to someone who uses InDesign.
PPTX, as an editable slide deck.
PNG, as page images.

Save or export from Design, then open Files and download the result to your computer.

For the PDF route on its own, see IDML to PDF. For e-books, see IDML to EPUB.

What may not carry over

Design is pre-alpha. That is the stage named in its roadmap. Expect rough edges, and check the pages before you send or print anything.
Known gaps are listed by the developers in the app’s own gaps document. If a feature in your layout is not one of those listed above, assume it may not come through and check it by eye.
Fonts. Japanese text needs fonts that are built into the app; without them it falls back to system fonts, and a browser has none. Check any Japanese text closely.
Your original stays safe only if you keep it. Export to a new file name rather than overwriting the IDML you were sent.

Design is one of the ArtCraft team’s open-source Crafting Apps (MIT or Apache-2.0), shipped in Madosuite under the name Design.

Why not just use InDesign

If you work with layouts every day, InDesign may still be the tool your team expects. As of 14 November 2026 Adobe lists InDesign at US$22.99 a month on an annual plan, billed monthly, with a 7-day free trial. If you only need to open, check or convert a file someone sent you, a free app in a browser tab is often enough. Our InDesign alternative page compares the two.

To try it with your own file, start from the IDML page or the Design app page.