less median time to an editable file than the same-revision Code-OSS source build
A CALMER CODE-OSS EDITOR
A quieter place
to write code.
Open a project. Write code. Review your changes. Lean VS Code keeps the familiar tools and dials back the stuff that tries to grab your attention.
The editor, editing its own source. Take a closer look by opening the image.
MEASURED AGAINST ORIGINAL CODE-OSS
Less waiting.
Less overhead.
p95 to an editable file, versus 1.73 s for Code-OSS
On an Apple M3 Max, signed Lean v0.4.0 reached an editable file in 1.262 s median / 1.310 s p95 versus 1.608 / 1.727 s for Code-OSS 1.139.1 built from the fork's upstream base revision, across 30 paired warm-cache launches per app with isolated profiles and a 100 KiB file. The Code-OSS comparator was an unminified source build while Lean was minified; this is not a like-for-like comparison with an optimized or official VS Code distribution. Idle-memory readings varied between runs, so v0.4.0 makes no lower-memory claim. See raw results and the method
The release opens this test file about 346 ms sooner at the median than the original Code-OSS source build. The editor, Git review, terminal, and extension support stay available.
A DEVELOPER'S YEAR
Small waits add up.
6.8 hours
illustrative saving versus the Code-OSS source baseline
In the past year, Matti's ILOapps commits touched more than 70,000 files. In the v0.4.0 benchmark, Lean reached an editable file 346 ms sooner than the same-revision Code-OSS source build at the median. That would add up to about 6.8 hours if the app started separately for every file touch. The goal of saving a full second per launch would mean about 19.4 hours per 70,000 starts; that goal has not yet been measured.
Illustration: 70,276 file touches × 0.346 seconds ≈ 6.8 hours. The Code-OSS comparator was an unminified source build; Lean v0.4.0 was minified, so this is not a like-for-like optimized-distribution claim. The benchmark measures fresh app startup, not annual time saved; existing-window file opens follow another path. Git history covers 95 local ILOapps repositories, 26 September 2025–26 September 2026, and 14,206 Matti-authored non-merge commits across 39 active repositories. Repeated changes to a file count again; dependency/build paths and commits touching more than 100 files were excluded.
THE GOOD PARTS STAY
Your workflow already fits.
Get straight to the work
Files, project search, the integrated terminal, and local Git review are ready when you need them.
Choose your extras
A smaller set of extensions comes built in. Find more through Open VSX or install a local VSIX.
Keep your setup separate
Lean VS Code has its own app identity, settings, and extensions, so it can sit beside VS Code.
WHY THIS FORK EXISTS
Sometimes you just want to open a folder and code.
Code-OSS is a great foundation. Lean VS Code is a take on what happens when the editor puts writing code and reviewing local changes first.
It ships with fewer built-in extensions and turns off unsolicited AI prompts, recommendations, experiments, and telemetry by default. Signed app updates from GitHub are the one background check enabled by default; you can change when Lean VS Code checks in Settings. The editor and extension platform are still there; you decide what to add.
Read the project story on GitHubMADE FOR THE EVERYDAY LOOP
See what changed.
Keep moving.
Inspect local Git changes side by side in the familiar diff view, then get back to your code.
See the open-source project
READY TO TRY IT?
Open the project.
Get to work.
Download the signed, notarized DMG from GitHub and drag Lean VS Code into Applications. The current release is for Apple Silicon Macs.
Starting with v0.3.2, Lean VS Code checks for signed macOS updates and offers Restart to Update when one is ready. v0.3.2 can update to v0.4.0; v0.3.0 and the withdrawn v0.3.1 candidate need a manual install of v0.3.2 or newer once.