Online Tool Store
Kotlin Code Formatter
Kotlin Code Formatter is for a quick tidy of pasted code; a project should enforce the same style in its build rather than relying on anyone remembering.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Developer
Kotlin Code Formatter
Frontend preview — no upload or external service.
Formatted Kotlin
A 40-line file reformatted to 4-space indentation with trailing commas preserved and chained calls broken one per line at the 100-column limit.
How the Kotlin Code Formatter works
- Paste the Kotlin source — a file, a class, or a single function.
- Set the indentation and maximum line length your project uses.
- Copy the formatted output, or apply the same settings in your build so the formatting is enforced rather than manual.
FAQ
Does this match ktlint or the IDE formatter?
It follows the official Kotlin coding conventions, which both are based on. For a project already using ktlint or detekt, run that in the build — a formatter in the pipeline beats one anybody can forget.
Will it change my code's behaviour?
No. Formatting only alters whitespace and line breaks. It does not reorder statements, add imports, or change semantics.
Why does formatting belong in the build?
Because a shared style enforced by tooling removes an entire category of review comment. Formatting arguments in a pull request are a waste of everyone's time when a tool can settle them.
How we compare
| Feature | Online Tool Store | A CLI script | An IDE plugin |
|---|---|---|---|
| Nothing uploaded | ✓ | ✗ | Depends |
| Kotlin conventions | ✓ | ✓ | ✓ |
| No install | ✓ | ✗ | ✗ |
| Configurable line length | ✓ | ✓ | Sometimes |
Kotlin Code Formatter is for a quick tidy of pasted code; a project should enforce the same style in its build rather than relying on anyone remembering.