Meet KetraTerm: a modern, high-performance terminal available as a JetBrains IDE plugin
Modern TUIs, agentic coding tools, AI CLIs, interactive dashboards, and other advanced terminal applications increasingly depend on precise Unicode layout, modern keyboard protocols, mouse tracking, TrueColor, alternate screen buffers, shell integration, and fast incremental rendering.
The current default terminal in JetBrains IDEs still has rendering and compatibility issues with some modern TUI applications and terminal workflows.
I wanted to see whether a new terminal engine, designed from the beginning for modern workloads and built entirely on the JVM, could provide a better experience without sacrificing performance.
So I built KetraTerm from scratch in Kotlin.
A JVM terminal does not have to be slow
Performance was one of the main design requirements from the beginning.
KetraTerm uses compact primitive-backed storage instead of allocating a separate object for every terminal cell. Its parser and terminal mutation paths are designed for a low allocation profile, reducing garbage-collection pressure during heavy output and rapid full-screen updates.
The renderer tracks dirty regions and redraws only the rows and cells that actually changed instead of continuously repainting the complete terminal.
Terminal processing, frame publication, and UI painting are also decoupled. This allows application output to continue being processed while the UI renders stable frames.
The result is an engine designed for demanding terminal workloads such as:
- modern TUIs;
- agentic development tools and AI CLIs;
- continuously updating dashboards;
- large builds;
- verbose logs;
- applications that redraw many times per second.
Modern terminal compatibility
KetraTerm supports:
- Unicode 17.0;
- grapheme clusters and combining characters;
- wide and zero-width characters;
- complex emoji sequences and fallback fonts;
- terminal-aware character width handling;
- gap-free box-drawing and block rendering;
- 24-bit TrueColor;
- modern underline styles and independent underline colors;
- alternate screen buffers;
- modern mouse tracking and high-resolution mouse coordinates;
- bracketed paste;
- Kitty keyboard protocol;
- CSI-u and xterm modifyOtherKeys;
- application cursor and keypad modes.
Its Unicode support is not limited to decoding UTF-8. KetraTerm handles grapheme segmentation and display width as part of the fixed-cell terminal model, helping multilingual text, emoji, combining marks, and complex TUI layouts remain correctly aligned.
Shell integration and notifications
KetraTerm supports OSC 133 and OSC 7 shell integration.
This allows it to understand command boundaries, prompts, exit statuses, and the current working directory instead of treating the entire session as an unstructured stream of text.
It also supports native desktop and in IDE notifications.
Already running inside JetBrains IDEs
The KetraTerm plugin embeds the complete KetraTerm terminal engine directly inside IntelliJ IDEA, Android Studio, PyCharm, WebStorm, CLion, and other compatible JetBrains IDEs.
The same engine also powers a standalone desktop terminal for Windows, macOS, and Linux.
KetraTerm 0.1.0 is now publicly available: desktop archives are available through GitHub Releases, and the source code is available under the Apache 2.0 license.
Development remains active. New features, compatibility improvements, performance refinements, and deeper IDE integrations will continue to be released.
If you use a modern TUI, agentic tool, shell workflow, or Unicode-heavy application that behaves incorrectly in your current IDE terminal, try the same workflow in KetraTerm.
Whether KetraTerm handles it better or still exposes a bug, please report the result. Real-world compatibility reports will help make KetraTerm better.
JetBrains plugin:
https://plugins.jetbrains.com/plugin/32589-ketraterm
Website:
https://ketraterm.github.io/KetraTerm/
GitHub and desktop downloads:
https://github.com/ketraterm/KetraTerm