Koi vs. Sublime Text

This comparison examines both editors across five categories: performance, workflow, customization, AI, and ownership.

• Performance
• Workflow
• Customization
• AI
• Ownership
• Summary

At a glance:

• Koi focuses on editing performance, local-first development, and document-based workflows.
• Sublime Text is a mature cross-platform editor with flexible layouts and a large package ecosystem.

Performance

Typing latency

Lower latency means the editor responds more quickly to each keypress. All measurements in milliseconds.

Dual pane displays the same document simultaneously in two editor panes while typing in one pane.

sqlite3.c (151,639 lines)

Dual pane:

gcc.c (753,821 lines)

Dual pane:

• Sublime Text was tested with auto-complete disabled for gcc.c because enabling it made editing the larger test file unusable.

Large file handling

Large file performance measures whether an editor can open and navigate very large files while remaining responsive.

An editor passes when it opens and becomes responsive with syntax highlighting working throughout the document within 30 seconds.

• Sublime Text meets the benchmark requirements at 1M and 5M lines. It does not meet them at 10M lines.

Large file memory usage

Memory is measured after opening, navigating, and editing the file and allowing the editor to settle.

Large file typing latency

P95 latency for each file size that remained usable in the large-file benchmark.

Test environment

Typing latency is measured using Keypress.sh, which records the time between a simulated keypress and the updated frame appearing on screen. Graphical applications are launched directly from their bundled Mach-O executables.

See Benchmarks for the complete methodology, configurations, raw measurements, and results for other editors.

Workflow

Koi and Sublime Text share several workflow concepts, including multiple windows, multiple panes, and tab multi-select.

Both editors support selecting multiple tabs and automatically displaying them side by side.

• Koi extends this around a shared document model. A document can remain open and synchronized across multiple Koi windows, and tabs can be reorganized between those windows without creating independent copies of the document.
• Sublime Text provides more flexible pane layouts and supports macOS, Windows, and Linux.

Customization

Editor configuration

Both editors are designed around editable configuration files.

• Koi keeps most editor configuration in a single configuration file.
• Sublime Text uses JSON-based settings, keymaps, themes, syntax definitions, project files, and other resource files.

Automation and plugins

Both Koi and Sublime Text use Python for editor automation.

Koi scripts can directly access the editor API and add commands from a user scripts file.

For example:

1. Write command, def sort_imports(): ...
2. Save
3. Run

Sublime Text also exposes an extensive Python API for commands, views, windows, selections, completions, events, and other editor functionality.

Sublime has the more mature extension ecosystem. Package Control provides thousands of packages covering languages, LSP support, linting, themes, terminals, Git integrations, snippets, and other functionality.

AI

Koi includes local AI functionality directly in the editor.

• Koi can use local models through Ollama for code completion and inline commands.
• Sublime Text does not include an AI assistant in the core editor.

Ownership

Both Koi and Sublime Text can be purchased without a recurring subscription.

• Koi Personal licenses are a one-time purchase and include future updates for the lifetime of the product. Team and Business licenses are renewed annually. Non-commercial use is free.
• Sublime Text can be downloaded and evaluated for free, but a license is required for continued use. Current Sublime Text licenses include three years of updates.

Summary

Choose Koi if you value:

• Lower measured typing latency
• Larger file support
• Local-first AI
• Context-aware auto-complete
• Multi-window document management
• Python automation
• No account or subscription
• One-time purchase

Choose Sublime Text if you value:

• A mature package ecosystem
• Cross-platform support
• Flexible pane layouts
• Python plugins
• Broad language and tooling support
• A long-established editor and plugin ecosystem

Related:

• Code Editor Performance Benchmarks
• Koi vs. Zed
• Koi vs. BBEdit