How to open .KT files on Windows
To open .KT files on Windows, install and open IntelliJ IDEA or Android Studio.
Step-by-step instructions
- Install and open IntelliJ IDEA or Android Studio.
- Use File → Open and select the folder/project containing the .kt file (recommended), or open the .kt file directly for viewing/editing.
Common issues
The file opens in the wrong app or shows as plain text without Kotlin features
Operating systems may not associate .kt with a Kotlin IDE, or you may be opening a single file outside its project so the IDE cannot resolve dependencies.
- Open the containing project/folder in IntelliJ IDEA or Android Studio instead of opening only the file.
- Set your file association to your preferred editor/IDE if you want .kt to open there by default.
Kotlin code has errors because imports/dependencies cannot be resolved
A .kt file often relies on other source files and build configuration from its project; opening it alone can cause unresolved references.
- Obtain the full project (not just the .kt file) and open the project in the IDE.
- If the project uses a build system, let the IDE finish project sync/indexing so it can download/resolve dependencies.
The file extension is misused and the content is not Kotlin source
While .kt is commonly used for Kotlin source, a file may be mislabeled or unrelated; it may not contain valid Kotlin code.
- Open the file in a plain-text editor to confirm it contains Kotlin code (e.g., package/import statements, Kotlin syntax).
- If it is not Kotlin, ask the sender for the correct file type or the correct project/context.
Security note
.kt files are plain-text source code, but they can contain code that does harmful things if you compile and run it; do not build/run untrusted Kotlin projects.