ByteRunner
An interactive scratchpad for the JVM
Write a few lines of Kotlin, Java, Groovy, or Scala and see the results instantly — as tables, trees, and charts, not a wall of text. Query databases, debug, and test, all in one lightweight desktop app.
data class Person(val name: String, val age: Int)
val people = listOf(
Person("Alice", 30),
Person("Bob", 25),
)
dump(people, "People") // renders as a sortable table
Users.where { u -> u.age gt 21 } // typed queries against your database
.select { u -> listOf(u.name) }What it does
Four JVM languagesWrite Kotlin, Java, Groovy, or Scala and run it instantly — no project setup, no build files, no boilerplate.
Rich results with dump()Call dump() on anything. Collections become sortable tables, objects become expandable trees, and JSON, XML, and images render natively.
Databases built inConnect to PostgreSQL, MySQL/MariaDB, SQLite, H2, SQL Server, or DynamoDB. Browse schemas, then query with SQL or a typed API like Users.where { u -> u.id gt 5 }.
A real debuggerSet breakpoints in the gutter, step through your script, inspect variables live, and evaluate expressions while paused.
Tests, inlineDeclare @Test methods right in a query and run them with one command — pass/fail per test, with failure messages and timings.
My ExtensionsKeep your helper functions in one per-language file and use them from every query — no imports, no copy-paste.
AI assistantAsk about your code, your schema, or an error with full context. Works with Anthropic, OpenAI, or a fully local Ollama model.
Runs you can killRun risky code in an isolated process whose Stop button actually stops it — even a runaway infinite loop.
Get ByteRunner
ByteRunner runs on Windows. The app checks for updates on startup and tells you when a new version is available.