Why an Online InDesign Version Converter Is Better: The Ultimate Guide to Effortless File Compatibility

: The most universal way to "back-save" a file is to open it in the newer version and select File > Export to save it as an InDesign Markup (IDML)

How to Use an Online InDesign Version Converter (Step-by-Step)

Open InDesign documents in previous versions - Adobe Help Center

online converter

An would accept an uploaded .indd file, detect its version, and output a target-version .indd or .idml (InDesign Markup Language) file.

Markzware’s Online ID Converter

Recommendation: Start with or ConversionTools’ InDG – both offer free trials and are industry standards.