Install and Update Claude Code CLI: Mac, Linux, Windows

Installing Claude Code is one command per platform – curl -fsSL https://claude.ai/install.sh | bash on macOS, Linux, and WSL, or irm https://claude.ai/install.ps1 | iex in Windows PowerShell – and updating is either automatic (the default) or one claude update. The part most pages skip is everything after that first command: which install method to pick when you have four, how the autoupdater behaves and how to turn it off, how to pin a specific version, and how to uninstall each method cleanly. This page is that reference, one table per job, current as of v2.1.224 (August 2026).¹

TL;DR

• Use the native installer. It has no Node.js dependency, ships the tested binary per platform, and has been the default since v2.1.113. The npm package is legacy – deprecated since v2.1.15, and it now requires Node.js 22+.¹
• Updates are automatic by default: Claude Code checks at startup and periodically during sessions, downloads in the background, and applies on the next launch. claude update forces one now.²
• Turning updates off is two different switches: DISABLE_AUTOUPDATER=1 stops background updates; DISABLE_UPDATES=1 (v2.1.118+) blocks every update path including a manual claude update.²
• Pin a version by passing it to the installer: curl -fsSL https://claude.ai/install.sh | bash -s 1.0.58. Check what you run with claude --version; browse what changed with /release-notes.¹²
• When anything misbehaves, run claude doctor – it reports install type, version, and detected issues, and since v2.1.205 the in-session /doctor diagnoses and fixes setup problems.²

How Do I Install Claude Code CLI?

One command, by platform:

# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

# Windows CMD
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

Prefer a package manager? Both are first-class:

brew install --cask claude-code          # macOS / Linux (stable channel)
winget install Anthropic.ClaudeCode      # Windows

Then run claude in a project directory and authenticate with a Claude Pro/Max/Team subscription or an Anthropic API account.¹ The native installer needs no Node.js, no sudo, nothing pre-installed. If you must use the legacy npm path (npm install -g @anthropic-ai/claude-code), it requires Node.js 22 or later and should never be run with sudo – root-owned global modules create permission problems that outlive the install.¹ Already on npm? claude install migrates you to the native binary in place.

For first-session setup – authentication choices, the first prompt, permission modes – the quickstart walkthrough covers the path from zero to first result.

Which Platforms Does Claude Code Support?

The recurring Windows question: native Windows works and needs no administrator rights; Anthropic’s own guidance is to pick by where your projects live and what you need, with WSL 2 when you want Linux toolchains or sandboxed command execution, and the same Linux installer runs inside it.³

How Do I Update Claude Code?

You usually don’t have to. Claude Code auto-updates by default – it checks for a new version at startup and periodically during sessions, downloads in the background, and applies the update the next time it launches.² To force an update immediately, or if you’ve disabled the autoupdater:

claude update

Package-manager installs update through their own channel – brew upgrade --cask claude-code, winget upgrade Anthropic.ClaudeCode – and since v2.1.129, setting CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE=1 lets those installs run the package-manager upgrade in the background and prompt for a restart.²

Controlling updates is two distinct switches, and the difference matters in locked-down environments:

Set either as an environment variable or under "env" in settings.json.²

How Do I Install a Specific Version?

Pass the version to the installer – useful for reproducing a bug, holding a team on a known-good release, or rolling back:

# Specific version
curl -fsSL https://claude.ai/install.sh | bash -s 1.0.58

# Latest, explicitly
curl -fsSL https://claude.ai/install.sh | bash -s latest

# Windows PowerShell, specific version
& ([scriptblock]::Create((irm https://claude.ai/install.ps1))) 1.0.58

Confirm with claude --version, and read what any release changed with the in-session /release-notes picker.² If you pin, pair it with DISABLE_AUTOUPDATER=1 – otherwise the autoupdater will politely un-pin you at the next launch. (Use DISABLE_UPDATES=1 instead when you also want manual claude update locked out.)

How Do I Uninstall Claude Code?

Match the uninstall to the install method:

Your configuration lives separately in ~/.claude/, so removing the binary does not delete settings, skills, or history – delete that directory too only if you want a truly clean slate.¹

The Whole Lifecycle in One Table

And when something is off – wrong version reported, command not found after an update, an install that half-applied – claude doctor from the shell reports installation type, version, and detected issues, while /doctor inside a session (v2.1.205+) runs a full checkup that can fix what it finds.² The full Claude Code guide covers everything past installation: configuration, permissions, hooks, MCP, and subagents.

Windows Troubleshooting: claude Not Recognized, Wrong Shell, Blocked Scripts

Most Windows failures are one of nine, each with a recognizable error string. Every fix below comes from Anthropic’s installation troubleshooting page and setup page as of 2026-09-07.³⁴

1. 'claude' is not recognized as an internal or external command (CMD) or The term 'claude' is not recognized as the name of a cmdlet (PowerShell). The installer placed claude.exe at %USERPROFILE%\.local\bin\claude.exe; that directory is not on your PATH, or you are still in the terminal you installed from, which keeps its old PATH. Check, add, then open a new terminal:⁴

$env:PATH -split ';' | Select-String '\.local\\bin'      # no output = not on PATH
$currentPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
[Environment]::SetEnvironmentVariable('PATH', "$currentPath;$env:USERPROFILE\.local\bin", 'User')

In CMD the check is echo %PATH% | findstr /i "local\bin", and the fix is adding %USERPROFILE%\.local\bin to the User PATH under Environment Variables.⁴

2. 'irm' is not recognized, The token '&&' is not a valid statement separator, or A parameter cannot be found that matches parameter name 'fsSL'. You ran the install line for a different shell. irm missing means you are in CMD (the prompt reads C:\): use the CMD installer above, or open PowerShell (PS C:\). && rejected means you are in PowerShell running the CMD line: use irm https://claude.ai/install.ps1 | iex. The fsSL complaint means you pasted the macOS/Linux curl -fsSL ... | bash line into PowerShell, where curl is an alias for Invoke-WebRequest. If the command prints the script’s text and installs nothing, you ran the download half without the part that executes it.⁴

3. running scripts is disabled on this system / PSSecurityException. PowerShell’s execution policy is blocking the .ps1 launcher shims that npm creates (npm.ps1, claude.ps1). It does not affect the native installer, which runs the downloaded text through iex rather than a saved file, and a saved ClaudeInstall.ps1 run with -ExecutionPolicy Bypass -File is not one of Anthropic’s documented install paths (the setup page lists only the irm line, the CMD installer, WinGet, and npm). Fixes, in order: Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser; or call claude.cmd (the policy does not cover .cmd); or replace the npm install with the native installer.⁴

4. iex parse errors that quote HTML tags or CSS, or curl: (22) The requested URL returned error: 403. The install URL returned a web page instead of the script. If the page says “App unavailable in region”, Claude Code is not offered in your country; otherwise a proxy or filter is in the way. Test reachability with curl.exe -sI https://downloads.claude.ai/claude-code-releases/latest (call curl.exe explicitly; PowerShell’s curl alias rejects -sI), where a 200 first line means the host is reachable and the failure was transient. winget install Anthropic.ClaudeCode is the documented alternative.⁴

5. Could not establish trust relationship for the SSL/TLS secure channel, or CRYPT_E_NO_REVOCATION_CHECK (0x80092012). For the first, force TLS 1.2 before the installer: [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12. The revocation errors mean your network blocks certificate revocation lookups; add --ssl-revoke-best-effort to the CMD curl line, or use the PowerShell installer, which downloads through .NET and tolerates an unreachable revocation server.⁴

6. The process cannot access the file ... because it is being used by another process. A previous installer is still running or antivirus is scanning a partial download in %USERPROFILE%\.claude\downloads. Close other PowerShell windows, wait for the scan, then:⁴

Remove-Item -Recurse -Force "$env:USERPROFILE\.claude\downloads"
irm https://claude.ai/install.ps1 | iex

7. The wrong version runs, or two installs disagree. where.exe claude lists every claude on your PATH; Test-Path "$env:USERPROFILE\.local\bin\claude.exe" says whether the native installer placed its binary. Keep the native one and remove the rest (winget uninstall Anthropic.ClaudeCode, npm uninstall -g @anthropic-ai/claude-code, Remove-Item -Recurse -Force "$env:USERPROFILE\.claude\local" for a legacy local npm install). claude doctor prints the installation type and version it is actually running.⁴

8. Claude Code on Windows requires either Git for Windows (for bash) or PowerShell. Neither shell was found. Git for Windows is optional: without it Claude Code runs commands through its PowerShell tool; with it, the Bash tool uses Git Bash. If Git Bash is installed but not found, point at it in settings.json:³

{
  "env": {
    "CLAUDE_CODE_GIT_BASH_PATH": "C:\\Program Files\\Git\\bin\\bash.exe"
  }
}

9. Claude Code does not support 32-bit Windows. You opened the x86 PowerShell entry on a 64-bit machine. Open “Windows PowerShell”, not the “(x86)” one.⁴

If none of these match, claude doctor (read-only, no session started) reports install health, settings-file errors, and the result of the last update attempt, and Anthropic’s troubleshooting page keeps the full error-to-fix table.³⁴

FAQ

How do I update Claude Code CLI to the latest version?

Run claude update, or simply restart – Claude Code checks for updates at startup and during sessions by default, downloading in the background and applying on next launch. Homebrew and winget installs update via brew upgrade --cask claude-code and winget upgrade Anthropic.ClaudeCode instead.

Does Claude Code update automatically?

Yes, by default: it checks at startup and periodically while running, then applies the downloaded update on the next launch. DISABLE_AUTOUPDATER=1 turns background updates off while keeping manual claude update; DISABLE_UPDATES=1 blocks every update path.

How do I install Claude Code on Windows?

Run irm https://claude.ai/install.ps1 | iex in PowerShell (or winget install Anthropic.ClaudeCode). Native Windows 10 (1809+) is supported on x64 and ARM64 with no admin rights; choose WSL 2 when you need Linux toolchains or sandboxed command execution, and expect the Linux installer to run inside it for full Linux parity – run the Linux install command inside it.

Do I need Node.js to install Claude Code?

No – the recommended native installer has no Node.js dependency. Only the legacy npm package (npm install -g @anthropic-ai/claude-code, deprecated since v2.1.15) needs Node, and it requires Node.js 22 or later. If you are on the npm install, claude install migrates you to the native binary.

How do I check which version of Claude Code I have?

claude --version from the shell, or /release-notes inside a session for an interactive changelog picker. claude doctor additionally reports the installation type and any detected setup issues.