Editor Comparison · Updated: Sep 26, 2026 · View as Markdown

Koi vs. Sublime Text

Performance ⋅ Privacy ⋅ Local AI ⋅ Language support ⋅ Scripting ⋅ Pricing

	Koi	Sublime Text
Cross-platform	Koi is Mac-only.	Mac, Windows, Linux.
Telemetry or tracking	None.	Yes
Local AI	Yes	Via packages.
Typing latency	Very fast: 16.6 ms.	Fast: 30.4 ms.
Large file editing	Usable through 20M lines.	Degraded at 5M lines, failed 10M.
Extensibility	Python scripting.	Python scripting and plugins.
Open source	Proprietary software.	Proprietary software.
One-time purchase	One-time purchase with lifetime updates.	No

Performance

TL;DR

Koi measured about 1.82x faster than Sublime Text in typing latency.

At 5 million lines, Koi used 698 MB of memory and remained responsive. Sublime Text used 1.10 GB and did not pass the 10-million-line test.

In our tests, Koi measured a lower typing latency and remains usable with larger files. On a 753,821-line C file:

	Koi	Sublime Text
Typing latency, p95	16.6 ms	30.4 ms
Dual-pane latency, p95	16.4 ms	32.2 ms

The difference becomes more visible with multi-million-line files.

	Koi	Sublime Text
1M lines	207.6 MB	259.6 MB
5M lines	698.3 MB	1.10 GB
10M lines	1.10 GB	-
20M lines	2.32 GB	-

Koi continued syntax highlighting and editing through the 20-million-line test. Sublime Text met the benchmark requirements at 5 million lines, but did not become usable within the benchmark limit at the 10-million-lines test.

See Benchmarks for the test methodology, memory usage, raw measurements, and results from other editors.

Privacy

Koi does not make network requests during normal use. There is no telemetry, automatic update check, or background download of language servers or other tooling.

Sublime Text includes telemetry for reporting anonymous usage information such as computer specifications, startup time, installed packages, and edited file types. File names and contents are not included.

Sublime Text also makes network requests for update checks. These checks can be disabled.

	Koi	Sublime Text
Account required	No accounts.	No
Telemetry	No telemetry.	Yes
Network requests during normal use	None.	Yes
Offline mode	Not needed.	No
Privacy policy document	Koi's Privacy Policy	-

Sublime Text's Package Control adds additional network activity when installed. By default, it checks for package updates and submits aggregate package usage data.

Local AI

Koi includes local AI functionality directly in the editor.

Code completion can run continuously against a small local model through Ollama. Inline commands can also use local models without an account or API key.

Sublime Text does not include AI functionality in the core editor. AI integrations are available through third-party packages and external tools.

	Koi	Sublime Text
Built-in AI features	Yes	No
Local model support	Yes	Via packages

Koi treats local AI as part of the editor rather than an extension.

Language support

Both editors include broad syntax support out of the box.

Koi currently ships with 30+ built-in lexers. They are handwritten, maintained as part of Koi, and included with the application.

Sublime Text also includes syntax definitions for 30+ languages. Additional languages are available through Package Control.

Koi owns and maintains its lexer implementation directly. Sublime Text uses declarative .sublime-syntax definitions and can add additional languages through packages.

See Lexer design in Koi for why Koi uses handwritten lexers.

Scripting

Koi exposes editor functionality directly to a user scripts file. A custom command can be as simple as:

@command("Word count")
def word_count():
    import re

    text = selected_text()
    count = len(re.findall(r"\b[\w'-]+\b", text))

    message(f"Word count: {count:,} words")

Save the script and run it.

Sublime Text has a mature Python API covering commands, views, windows, selections, completions, events, and other editor functionality.

	Koi	Sublime Text
Python API	Yes	Yes
Custom commands	Yes	Yes
Edit and reload directly	Yes	Yes
Package manager	No	Yes

Sublime Text has the larger extension ecosystem.

Koi keeps scripting closer to the editor. Personal commands don't need to become packages.

Pricing

Both editors are commercial software.

Koi is free for non-commercial use. A personal license is a one-time purchase and includes future updates for the lifetime of the product.

Sublime Text can be evaluated for free. A personal license includes three years of updates. After that, a paid upgrade is required to use newer versions.

	Koi	Sublime Text
Free editor	Non-commercial use	Evaluation
Lifetime license	Yes	No
Paid cloud services	No	No
Open source	No	No
Pricing page	Koi's Pricing	Sublime Text's Store