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.
Editions
Free
- All four languages — Kotlin, Java, Groovy, Scala
- dump() visualization: tables, trees, JSON, images
- Inline tests, My Extensions, killable isolated runs
- Search Scripts, tabs, layouts, themes
Pro
- Database connectivity + schema explorer + typed queries
- Debugger — breakpoints, stepping, live variables
- AI assistant (Anthropic, OpenAI, or local Ollama)
- Code completion & Maven dependencies (@file:DependsOn)
Every install includes a 14-day Pro trial. Pro pricing is being finalized — it'll be announced here.
FAQ
Do I need Java installed?No. ByteRunner bundles its own JDK 21 runtime — download, install, run. Compiling and debugging work out of the box.
Windows says "unknown publisher" when I install. Is that expected?For now, yes — the installers aren't code-signed yet (signing is in progress). Choose "More info → Run anyway". Installers only ever come from this site and the ByteRunner-releases GitHub repo.
Does my code leave my machine?No — queries compile and run locally. The only network calls are the update check and the AI assistant if you enable it (and even that can run fully local via Ollama).
How do updates work?ByteRunner checks this site on startup and tells you when a new version is available. Nothing is auto-installed; you download when you're ready.
What platforms are supported?Windows 10/11 today, via Setup.exe or MSI. macOS and Linux builds are planned.
Get ByteRunner
ByteRunner runs on Windows. The app checks for updates on startup and tells you when a new version is available.