🔤 The PowerShell Chinese Encoding Trap — Why Your Files Come Out Garbled

The Symptom

You write a PowerShell script that outputs Chinese text to a file. You open the file. Garbage. Not corrupted — wrong encoding.

Layer 1: PowerShell's Default Output Encoding

PowerShell defaults to the system's active code page — often GBK on Chinese Windows, or UTF-16 LE with BOM. Neither is what you want if other tools expect UTF-8.

Fix at the top of your script:

[Console]::OutputEncoding = [System.Text.Encoding]::UTF8
$OutputEncoding = [System.Text.Encoding]::UTF8

Layer 2: Out-File vs Set-Content

Out-File in older PowerShell uses UTF-16 LE with BOM by default. Use Set-Content with explicit encoding instead:

Set-Content -Path "output.txt" -Value $content -Encoding UTF8

Layer 3: BOM

UTF-8 with BOM adds three invisible bytes. Most Linux tools and APIs don't handle it. For cross-platform files, use UTF-8 without BOM:

[System.IO.File]::WriteAllText(
    (Resolve-Path "output.txt"),
    $content,
    [System.Text.UTF8Encoding]::new($false)  # false = no BOM
)