OpenAnyFile
Works
Viewing, inspecting and verifying. You get the source with language-aware colouring and line numbers. File details, exact byte size and the detected signature are always shown.
How to open a .kt file
You have a KT file and nothing on your machine will touch it. Here is what the format actually is, and how to read one in about four seconds without installing anything.
What is a .kt file?
Kotlin Source is a code format developed by JetBrains, first appearing in 2011. It is normally produced by Android apps, JVM backends.
Google's preferred Android language since 2019. Fully interoperable with Java in the same project.
| Full name | Kotlin Source |
|---|---|
| File category | Code |
| MIME type | text/x-kotlin |
| Developer | JetBrains |
| Introduced | 2011 |
| Usually created by | Android apps, JVM backends |
| OpenAnyFile engine | syntax highlighter |
| Opens without upload | Yes — parsed locally in your browser |
Open a .kt file in your browser
OpenAnyFile routes .kt to its syntax highlighter, which highlights the source with language-aware colouring and line numbers.
- Open the OpenAnyFile opener in this browser — nothing to download or sign up for.
- Drag your .kt file onto the drop zone, click to browse for it, or paste it with Ctrl+V.
- The extension is detected and the file is handed to the syntax highlighter.
- Your KT opens on its own viewer page: the source with language-aware colouring and line numbers.
- Use fullscreen for a closer look, or download the file back out unchanged. Nothing is transmitted anywhere — the parsing happens in your own browser process.
What you can and cannot do with it here
Does not work
Editing and re-saving. OpenAnyFile is a reader, not an editor — for changes you still need special software or an equivalent.
Why your {ext} file is never uploaded
Most online viewers work by sending your file to their server, processing it there, and leaving a copy behind on infrastructure you do not control. OpenAnyFile does not. Your .kt file is read through the browser's local File API and decoded by JavaScript and WebAssembly running on your own machine. There is no upload step and no server-side copy — open your browser's network tab while you do it and watch: the file never appears.
Frequently asked questions about KT files
Can I open a .kt file without installing special software?
Yes. OpenAnyFile's syntax highlighter runs in your browser, so you can read a KT file with nothing installed. You get the source with language-aware colouring and line numbers. For full editing you still need the original application — this is a viewer, not an editor.
How can I tell what a .kt file actually contains?
The .kt extension carries no fixed signature, so the extension alone proves nothing. Opening it in OpenAnyFile shows the raw header bytes and detected type, which is the only reliable way to identify one.
Is it safe to open a KT file online?
With OpenAnyFile, yes, because nothing is uploaded. The file is read locally through your browser's File API and never leaves your device, so there is no server copy to leak, log or retain. That matters most for the kind of file people are least willing to hand to a random converter site.
What is a .kt file, exactly?
Kotlin Source — a text/x-kotlin format created by JetBrains since 2011. Google's preferred Android language since 2019. Fully interoperable with Java in the same project.
Does the same viewer handle formats related to KT?
Yes — the same engine also opens .html, .xml, .sql, so you can compare related files without switching tools.
Related formats
These open with the same engine, so if you have one of these sitting next to your .kt file, it will open too: