Kotlin Compressor

Kotlin compression removes all developer-facing content from a Kotlin source file — comments, blank lines, and trailing whitespace — that the Kotlin compiler ignores at compile time. Kotlin supports three comment styles: single-line //, multi-line /* ... */ (which are nestable — a unique Kotlin feature), and KDoc /** ... */ for API documentation. Our kotlin compressor handles all three correctly, including the nestable multi-line comment depth tracking that simpler regex-based tools get wrong. It also correctly preserves triple-quoted raw strings ("""...""") which can contain text that looks like comments but must not be modified.

1. 1Paste or upload your Kotlin: Paste any Kotlin source code or upload a .kt or .ktsfile. Use the "Load sample" button to try the compressor with a realistic Kotlin class. The line count and byte size update in real time.
2. 2Configure compression options: Toggle any of the 6 compression options — by default, KDoc comments (/** ... */) are preserved so API documentation and license headers are not removed. All processing happens locally in your browser — your Kotlin code never leaves your device.
3. 3Copy or download the compressed Kotlin: The compressed output appears in the right panel. Copy it to clipboard with one click, or download as abacktools-compressed.kt. The stats bar shows original size, compressed size, bytes saved, reduction percentage, and lines removed.

• Single-line comments (//): All single-line comments are removed. The newline at the end of each comment line is preserved to maintain line structure and avoid merging adjacent code tokens.
• Multi-line comments (/* ... */) with nesting: Kotlin uniquely allows nested multi-line comments. The compressor tracks nesting depth correctly — /* outer /* inner */ still outer */ is treated as a single comment block and removed entirely.
• Blank lines and trailing whitespace: Empty lines and lines containing only whitespace are removed. Trailing spaces and tabs on each line are stripped. Multiple consecutive blank lines can be collapsed to a single blank line.
• String literals preserved: Content inside double-quoted strings, triple-quoted raw strings ("""..."""), and character literals is never modified — the compressor tracks all string boundaries character by character.

This kotlin compressor uses character-by-character parsing rather than a full Kotlin AST parser. It handles all standard Kotlin comment and string types correctly, including nestable multi-line comments and triple-quoted strings. However, it does not perform semantic analysis — it cannot detect comments inside complex expressions or handle annotation processors that read comment content at compile time. Always test the compressed output before using it in production builds. For Kotlin Script (.kts) files, the same rules apply — all comment types are handled identically.