[BUG] Claude code bash command execution, output Chinese characters appear as garbled text

[zhatlas]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

My system environment is Windows 10, Windows Terminal, Git Bash, Claude Code 1.0.109.

When executing commands with Chinese output, the output shows garbled characters.

What Should Happen?

Should display Chinese characters

Error Messages/Logs

Steps to Reproduce

NA

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

1.0.109

Platform

Other

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

This is caused by inconsistencies in the multi-layer encoding chain——the bash end is typically set to UTF-8, while the called native Windows commands/external programs (especially PowerShell 5, cmd tools) use the console code page (OEM/ANSI) or UTF-16/CPxxxx in the pipeline, resulting in a mismatch at both ends, naturally causing byte errors.

You can refer to this issue: google-gemini/gemini-cli#1945

[github-actions]

Found 3 possible duplicate issues:

1. Unicode/UTF-8 Character Corruption in Hook System #6246
2. [BUG] Claude code creates a code file or writes to an empty file. Chinese characters are garbled. #5047
3. [BUG] Unicode Character Input Corruption in Claude Code Terminal #6094

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
• To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

[zhatlas]

Forcing the output format of the calling program to UTF-8 can resolve this issue. For instance, in the following PowerShell script, changing PowerShell's output encoding to UTF-8 ensures that when Claude Code executes a PowerShell command via bash, the output from PowerShell will not have any encoding issues within Claude Code.

# --- Ensure CurrentUserAllHosts profile exists (PS5) ---
$profilePath = $PROFILE.CurrentUserAllHosts  # Usually  %UserProfile%\Documents\WindowsPowerShell\profile.ps1
$null = New-Item -ItemType File -Path $profilePath -Force

# --- UTF-8 init block for PS5 (idempotent, between markers) ---
$block = @'
# >>> UTF8_FIX_PS5_BEGIN >>>
try { chcp 65001 > $null } catch {}
# Unify the encoding of standard input/output to UTF-8 (affects console and pipes)
[Console]::InputEncoding  = [Text.Encoding]::UTF8
[Console]::OutputEncoding = [Text.Encoding]::UTF8
$OutputEncoding           = [Console]::OutputEncoding
# Unify common file output encoding to UTF-8 (to avoid default UTF-16/ANSI)
$PSDefaultParameterValues['Out-File:Encoding']    = 'utf8'
$PSDefaultParameterValues['Set-Content:Encoding'] = 'utf8'
$PSDefaultParameterValues['Add-Content:Encoding'] = 'utf8'
# >>> UTF8_FIX_PS5_END >>>
'@

$raw = Get-Content -LiteralPath $profilePath -Raw -ErrorAction SilentlyContinue
if ($null -eq $raw) { $raw = "" }
$pattern = '(?s)# >>> UTF8_FIX_PS5_BEGIN >>>.*?# >>> UTF8_FIX_PS5_END >>>'
if ($raw -match $pattern) {
  $new = [regex]::Replace($raw, $pattern, [System.Text.RegularExpressions.Regex]::Escape($block) -replace '\\r\\n', "`r`n")
} else {
  $new = $raw.TrimEnd(), "`r`n", $block -join ""
}
Set-Content -LiteralPath $profilePath -Value $new -Encoding UTF8
Write-Host "Profile updated at: $profilePath" -ForegroundColor Green

However, Claude Code invokes many programs through bash, and it's quite challenging to change the output of all these programs to UTF-8. Therefore, this issue needs to be addressed from the Claude Code side. Additionally, it's worth mentioning that the Gemini CLI seems to be free of this problem.

[wywgong]

@zhatlas I've find the solution for this, the root cause is because in default(no matter in Windows 10/Windows 11 powershell 5.1 or the latest powershell 7+, the output from the powershell is default use the native language code page, in your case, I believe that's the GBK, namely code page 936), you can try to save the below code into ps1 file(powershell file, for example, call it "set-utf8-system-default.ps1"), then use the admin permission to run it, it will modify your powershell and cmd.exe default output code page to 65001(UTF-8), after that, the Claude code can show Chinese correctly. Hopefully it can help. at least works for me ^_^

# Set system default code page to UTF-8 (65001)
# This script must be run as Administrator

# Check if running as Administrator
$isAdmin = ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)

if (-not $isAdmin) {
    Write-Host "Error: This script must be run as Administrator" -ForegroundColor Red
    Write-Host "Please right-click this script and select 'Run as Administrator'" -ForegroundColor Yellow
    pause
    exit 1
}

Write-Host "Setting system default code page to UTF-8 (65001)..." -ForegroundColor Cyan

try {
    # Set OEM code page to UTF-8
    Set-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\Nls\CodePage' -Name 'OEMCP' -Value '65001' -Force

    # Set ACP (ANSI Code Page) to UTF-8
    Set-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\Nls\CodePage' -Name 'ACP' -Value '65001' -Force

    Write-Host "✓ System default code page has been set to UTF-8" -ForegroundColor Green
    Write-Host ""
    Write-Host "IMPORTANT: You must restart your computer for the changes to take effect!" -ForegroundColor Yellow
    Write-Host ""

    $restart = Read-Host "Do you want to restart now? (Y/N)"
    if ($restart -eq 'Y' -or $restart -eq 'y') {
        Write-Host "Restarting..." -ForegroundColor Cyan
        Restart-Computer -Force
    } else {
        Write-Host "Please restart your computer manually later to apply the changes" -ForegroundColor Yellow
    }
} catch {
    Write-Host "Error: $($_.Exception.Message)" -ForegroundColor Red
    pause
    exit 1
}

[github-actions]

This issue has been inactive for 30 days. If the issue is still occurring, please comment to let us know. Otherwise, this issue will be automatically closed in 30 days for housekeeping purposes.

[xrchz]

This issue is related to a broader UTF-8/encoding bug pattern in Claude Code's Edit/Write tools.

I've posted a consolidated impact analysis at #13939 showing this is part of a systemic encoding problem affecting Turkish, Nordic, Chinese, and other non-ASCII character sets.

Cross-linking for visibility: #13939, #13080, #7134, #7335

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