How to fix warning: commit message does not conform to UTF-8 in Git

First, verify what encoding settings Git currently uses:

# Check commit encoding setting
git config --get i18n.commitEncoding

# Check log output encoding
git config --get i18n.logOutputEncoding

# Show all i18n-related config
git config --list | grep i18n

If no value is returned for i18n.commitEncoding, Git assumes UTF-8 (which is the recommended default).

Ensure your terminal and text editor are configured to use UTF-8:

Terminal (Linux/macOS):

# Check current locale
locale

# Set UTF-8 locale (add to ~/.bashrc or ~/.zshrc)
export LANG=en_US.UTF-8
export LC_ALL=en_US.UTF-8

Windows Terminal/PowerShell:

# Set console output encoding to UTF-8
[Console]::OutputEncoding = [System.Text.Encoding]::UTF8
chcp 65001

VS Code: Open Settings and search for "encoding", then set "Files: Encoding" to "utf8".

Vim: Add to your .vimrc:

set encoding=utf-8
set fileencoding=utf-8

If your terminal is already configured for UTF-8, use the -m flag to provide the message directly:

# Commit with inline UTF-8 message
git commit -m "Fix: Handle umlauts correctly (Umlaute)"

This ensures the message is encoded in whatever encoding your terminal uses. If your terminal is UTF-8, the message will be UTF-8 encoded.

If you've already made a commit with the warning and want to fix it:

# Amend the last commit with a new message
git commit --amend -m "Your corrected UTF-8 message here"

# Or open the editor to re-type the message
git commit --amend

Make sure your editor and terminal are configured for UTF-8 before running this command.

If your project specifically requires a non-UTF-8 encoding, tell Git what encoding to use:

# Set encoding for this repository only
git config i18n.commitEncoding ISO-8859-1

# Or set globally for all repositories
git config --global i18n.commitEncoding ISO-8859-1

Supported encodings include:
- ISO-8859-x (Western European, etc.)
- CP125x (Windows code pages)
- Other extended ASCII encodings

Note: UTF-16, UTF-32, EBCDIC, and CJK multi-byte encodings (GBK, Shift-JIS, Big5, EUC-x) are NOT supported for commit messages.

If you need to fix historical commits with non-UTF-8 messages, use git filter-branch:

# Convert commit messages from ISO-8859-1 to UTF-8
git filter-branch --msg-filter 'iconv -f ISO-8859-1 -t UTF-8' -- --all

Warning: This rewrites commit history. Only do this on branches that haven't been shared with others, or coordinate with your team first.

For a safer approach on shared repositories, simply ensure all new commits use UTF-8 going forward.

After fixing, verify your commits are properly encoded:

# View the raw commit to check for encoding header
git cat-file -p HEAD

# Check if the commit has an encoding header
git log -1 --format='%H %e'

If the commit message is UTF-8 (the default), no encoding header will be present. If you set a different encoding, you'll see it listed in the commit object.