Pylance or Ruff? Understanding the Tools, Combining Them Right

Black-compatible means Ruff formats Python code by the exact same rules as the well-known tool Black — consistent quotes, fixed line length (88 chars), no style debates. It's a drop-in replacement: if you used Black before, you can switch to Ruff without changing a single line of code.

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TL;DR

Pylance ≠ Ruff. Both together = the strongest setup.

User Settings (%APPDATA%\Code\User\settings.json):

{
  "ruff.nativeServer": "on",
  "python.languageServer": "Pylance",
  "[python]": {
    "editor.defaultFormatter": "charliermarsh.ruff",
    "editor.formatOnSave": true
  }
}

Prerequisite: The VS Code extension charliermarsh.ruff must be installed. Only then will editor.defaultFormatter = charliermarsh.ruff actually take effect.

Recommendation: Put this block into the VS Code user settings, meaning %APPDATA%\Code\User\settings.json.

Workspace Settings (.vscode/settings.json in the project):

{
  "python.analysis.typeCheckingMode": "basic",
  "python.analysis.diagnosticMode": "openFilesOnly",
  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python"
}

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What does what? Two tools — one clear split

The most common misconception: Ruff does not replace Pylance. The two tools solve fundamentally different problems.

Feature	Pylance	Ruff
IntelliSense / Autocomplete	✅	❌
Type Checking (via Pyright)	✅	❌
Go-to-Definition	✅	❌
Hover Docs / Signatures	✅	❌
Linting (flake8, pylint, …)	weak	✅
Formatting (Black-compatible)	❌	✅
Import Sorting (isort)	❌	✅
Speed	normal	10–100× faster

Pylance is the Language Server — the engine behind IntelliSense, autocomplete, type checking and refactoring. Without Pylance (or an equivalent Pyright-based server), Python files are essentially "blind text" for VS Code.

Ruff is the linting and formatting tool — written in Rust, extremely fast, and designed as a drop-in replacement for flake8, pylint, isort, pyupgrade and Black. Everything in one single binary.

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Where do settings belong?

Rule of thumb: Tool preferences (which tool do I use?) → User Settings. Project behavior (how strict?) → Workspace Settings.

In my setup, I deliberately use this relief globally in User Settings. For teams or repositories with strongly differing standards, workspace scoping can still be the better compromise.

In the settings files concretely

User Settings (%APPDATA%\Code\User\settings.json):

{
  "ruff.nativeServer": "on",
  "python.languageServer": "Pylance",
  "[python]": {
    "editor.defaultFormatter": "charliermarsh.ruff",
    "editor.formatOnSave": true
  }
}

The same applies here: the formatter assignment only works if the charliermarsh.ruff extension is actually installed.

Workspace Settings (.vscode/settings.json in the project folder):

{
  "python.analysis.typeCheckingMode": "basic",
  "python.analysis.diagnosticMode": "openFilesOnly",
  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python"
}

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Installing Ruff: global or local?

Recommendation: both — global CLI + local binary in the venv.

Global (for all projects, no venv conflict):

# With pipx — recommended, because isolated:
pipx install ruff

# Or classically global:
pip install ruff

Project-local (in the project's venv):

# In the activated venv:
pip install ruff

Or as a dev dependency in pyproject.toml:

[project.optional-dependencies]
dev = ["ruff>=0.4.0"]

VS Code Extension (charliermarsh.ruff)

Prerequisite: the VS Code extension charliermarsh.ruff must be installed. The assignment editor.defaultFormatter = charliermarsh.ruff alone is not enough if the extension is missing.

Recommended entry for the VS Code user settings (%APPDATA%\Code\User\settings.json):

In my setup, the native Ruff server is also enabled:

{
  "ruff.nativeServer": "on",
  "[python]": {
    "editor.defaultFormatter": "charliermarsh.ruff"
  }
}

The extension is activated in User Settings — once, globally. It automatically detects the priority:

1. Project-own ruff binary in the venv → preferred
2. Globally installed ruff via pipx
3. Last fallback: bundled binary shipped with the extension

ext install charliermarsh.ruff

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Recommended setup 2026

1. Install extensions: ms-python.vscode-pylance + charliermarsh.ruff
2. Reduce Pylance linting (Ruff takes over):

   "python.analysis.diagnosticMode": "openFilesOnly"

3. Set Ruff as formatter (User Settings, once globally)
4. Per project: pyproject.toml or ruff.toml for lint rules

# pyproject.toml — Ruff configuration
[tool.ruff]
line-length = 120
target-version = "py311"

[tool.ruff.lint]
select = ["E", "F", "I", "UP"]  # flake8 + isort + pyupgrade
ignore = ["E501"]                # line length handled by formatter

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Copyright & Date

The blog date (March 21, 2026) is stored in the frontmatter and evaluated by the template. The author and copyright (© 2026 Nejat Philip Eryigit · ready-4-IT.com) come from the global site.yaml and appear in the page footer.

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Conclusion: Keep Pylance on — configure it right

Short version: Don't disable Pylance — configure it correctly. Toggling Pylance "on demand" creates unnecessary overhead with no real benefit.

Pylance is the engine behind IntelliSense, hover docs, go-to-definition and refactoring — the features that turn VS Code into a real IDE. Properly configured, it adds negligible overhead.

Permanently in User Settings (once, globally)

{
  "ruff.nativeServer": "on",
  "python.languageServer": "Pylance",
  "[python]": {
    "editor.defaultFormatter": "charliermarsh.ruff",
    "editor.formatOnSave": true
  }
}

In my current setup, this is intentionally configured user-wide. Teams with differing conventions may prefer a tighter scope and keep more project-specific rules in .vscode/settings.json.

Per project in .vscode/settings.json

{
  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python",
  "python.analysis.typeCheckingMode": "basic",
  "python.analysis.diagnosticMode": "openFilesOnly"
}

diagnosticMode: openFilesOnly is the key switch for Python projects with many files or external dependencies: Pylance only analyses currently open tabs instead of scanning the entire project in the background. This keeps the editor fast — even in larger projects with Vagrant scripts, PHP companion files or shared dependencies.

When to disable Pylance per workspace?

Only if a workspace has no dedicated venv — e.g. pure helper scripts without type dependencies. In that case a workspace-local override is enough:

{ "python.languageServer": "None" }

This disables Pylance only for that workspace, without touching the global User Setting.

The division of labour stays clear

Task	Tool	Where to configure
IntelliSense, type checking, refactoring	Pylance	User Settings (always on)
Linting, formatting, import sorting	Ruff	User Settings (always on)
Strictness of type checking	typeCheckingMode	Workspace Settings
Which venv to use	defaultInterpreterPath	Workspace Settings

flake8, pylint, mypy, isort, Black — no longer needed. Ruff replaces them all.

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© 2026 Nejat Philip Eryigit · ready-4-IT.com · Published: March 21, 2026

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