diff --git a/dataclaw/anonymizer.py b/dataclaw/anonymizer.py
index 045fe01..3f04aa8 100644
--- a/dataclaw/anonymizer.py
+++ b/dataclaw/anonymizer.py
@@ -1,5 +1,6 @@
 """Anonymize PII in Claude Code log data."""
 
+import functools
 import hashlib
 import os
 import re
@@ -15,60 +16,70 @@ def _detect_home_dir() -> tuple[str, str]:
     return home, username
 
 
-def anonymize_path(path: str, username: str, username_hash: str, home: str | None = None) -> str:
-    """Strip a path to project-relative and hash the username."""
-    if not path:
-        return path
+@functools.lru_cache(maxsize=32)
+def _get_username_pattern(username: str) -> re.Pattern:
+    escaped = re.escape(username)
+    # \b does not match word boundaries around underscore, but we need to match them
+    return re.compile(rf"(?<![a-zA-Z0-9]){escaped}(?![a-zA-Z0-9])", flags=re.IGNORECASE)
+
 
-    if home is None:
-        home = os.path.expanduser("~")
-    prefixes = set()
-    for base in (f"/Users/{username}", f"/home/{username}", home):
-        for subdir in ("Documents", "Downloads", "Desktop"):
-            prefixes.add(f"{base}/{subdir}/")
-        prefixes.add(f"{base}/")
+@functools.lru_cache(maxsize=32)
+def _get_home_pattern(username: str) -> re.Pattern:
+    escaped = re.escape(username)
+    # Match /Users/username , \Users\username , \\Users\\username , -Users-username (hyphen-encoded path like Claude Code and HuggingFace cache)
+    # Match conventional indicators of home dir: 'Users' and 'home'
+    # Ignore case for Windows-like path
+    return re.compile(rf"([/\\-]+(Users|home)[/\\-]+){escaped}(?=[^a-zA-Z0-9]|$)", flags=re.IGNORECASE)
 
-    # Try longest prefixes first (subdirectory matches before bare home)
-    home_patterns = sorted(prefixes, key=len, reverse=True)
 
-    for prefix in home_patterns:
-        if path.startswith(prefix):
-            rest = path[len(prefix):]
-            if "/Documents/" in prefix or "/Downloads/" in prefix or "/Desktop/" in prefix:
-                return rest
-            return f"{username_hash}/{rest}"
+@functools.lru_cache(maxsize=32)
+def _get_custom_home_pattern(home: str) -> re.Pattern | None:
+    if home.startswith(("/Users/", "/home/", "C:\\Users\\")):
+        return None
 
-    path = path.replace(f"/Users/{username}/", f"/{username_hash}/")
-    path = path.replace(f"/home/{username}/", f"/{username_hash}/")
+    # If home is not conventional, replace with more specific pattern
 
-    return path
+    # Escape home and replace / or \ with `r"[/\\-]+"`
+    home_escaped = home.replace("\\", "/")
+    home_escaped = re.escape(home_escaped)
+    home_escaped = home_escaped.replace("/", r"[/\\-]+")
+    # In WSL and MSYS2, C:\ may be represented by /c/
+    home_escaped = home_escaped.replace(":", ":?")
+    return re.compile(home_escaped, flags=re.IGNORECASE)
 
 
-def anonymize_text(text: str, username: str, username_hash: str) -> str:
+def anonymize_text(text: str, username: str, username_hash: str, home: str | None = None) -> str:
     if not text or not username:
         return text
 
-    escaped = re.escape(username)
+    if username.lower() not in text.lower():
+        return text
 
-    # Replace /Users/<username> and /home/<username>
-    text = re.sub(rf"/Users/{escaped}(?=/|[^a-zA-Z0-9_-]|$)", f"/{username_hash}", text)
-    text = re.sub(rf"/home/{escaped}(?=/|[^a-zA-Z0-9_-]|$)", f"/{username_hash}", text)
+    # Replace bare username in contexts (ls output, prose, etc.)
+    # Only if username is >= 4 chars to avoid false positives
+    if len(username) >= 4:
+        return _get_username_pattern(username).sub(username_hash, text)
 
-    # Catch hyphen-encoded paths: -Users-peteromalley- or -Users-peteromalley/
-    text = re.sub(rf"-Users-{escaped}(?=-|/|$)", f"-Users-{username_hash}", text)
-    text = re.sub(rf"-home-{escaped}(?=-|/|$)", f"-home-{username_hash}", text)
+    # When username is < 4 chars, replace with more specific patterns
 
-    # Catch temp paths like /private/tmp/claude-501/-Users-peteromalley/
-    text = re.sub(rf"claude-\d+/-Users-{escaped}", f"claude-XXX/-Users-{username_hash}", text)
+    text = _get_home_pattern(username).sub(rf"\g<1>{username_hash}", text)
 
-    # Final pass: replace bare username in remaining contexts (ls output, prose, etc.)
-    # Only if username is >= 4 chars to avoid false positives
-    if len(username) >= 4:
-        text = re.sub(rf"\b{escaped}\b", username_hash, text)
+    if home:
+        pat_home = _get_custom_home_pattern(home)
+        if pat_home:
+            pat_user = _get_username_pattern(username)
+            def f(match):
+                # match.group(0) is a non-escaped string
+                return pat_user.sub(username_hash, match.group(0))
+            text = pat_home.sub(f, text)
 
     return text
 
 
+# Backward compatibility
+anonymize_path = anonymize_text
+
+
 class Anonymizer:
     """Stateful anonymizer that consistently hashes usernames."""
 
@@ -77,29 +88,38 @@ def __init__(self, extra_usernames: list[str] | None = None):
         self.username_hash = _hash_username(self.username)
 
         # Additional usernames to anonymize (GitHub handles, Discord names, etc.)
-        self._extra: list[tuple[str, str]] = []
+        self._extra_dict = {}
         for name in (extra_usernames or []):
             name = name.strip()
-            if name and name != self.username:
-                self._extra.append((name, _hash_username(name)))
+            if name and name != self.username and len(name) >= 4:
+                self._extra_dict[name.lower()] = _hash_username(name)
+
+        self._extra = list(self._extra_dict.keys())
+
+        if self._extra_dict:
+            escaped_names = [re.escape(k) for k in sorted(self._extra_dict.keys(), key=len, reverse=True)]
+            self._extra_pattern = re.compile(rf"(?<![a-zA-Z0-9])({'|'.join(escaped_names)})(?![a-zA-Z0-9])", flags=re.IGNORECASE)
+        else:
+            self._extra_pattern = None
 
     def path(self, file_path: str) -> str:
-        result = anonymize_path(file_path, self.username, self.username_hash, self.home)
-        result = anonymize_text(result, self.username, self.username_hash)
-        for name, hashed in self._extra:
-            result = _replace_username(result, name, hashed)
-        return result
+        return self.text(file_path)
 
     def text(self, content: str) -> str:
-        result = anonymize_text(content, self.username, self.username_hash)
-        for name, hashed in self._extra:
-            result = _replace_username(result, name, hashed)
+        result = anonymize_text(content, self.username, self.username_hash, self.home)
+        if self._extra_pattern:
+            def f(match):
+                return self._extra_dict[match.group(1).lower()]
+            result = self._extra_pattern.sub(f, result)
         return result
 
 
 def _replace_username(text: str, username: str, username_hash: str) -> str:
-    if not text or not username or len(username) < 3:
+    if not text or not username or len(username) < 4:
         return text
-    escaped = re.escape(username)
-    text = re.sub(escaped, username_hash, text, flags=re.IGNORECASE)
-    return text
+
+    if username.lower() not in text.lower():
+        return text
+
+    pat = _get_username_pattern(username)
+    return pat.sub(username_hash, text)
diff --git a/tests/test_anonymizer.py b/tests/test_anonymizer.py
index 0320f7d..81d8111 100644
--- a/tests/test_anonymizer.py
+++ b/tests/test_anonymizer.py
@@ -39,56 +39,62 @@ class TestAnonymizePath:
     def test_empty_path(self):
         assert anonymize_path("", "alice", "user_abc12345") == ""
 
-    def test_documents_prefix_stripped(self):
+    def test_global_replace(self):
+        # if username is >= 4 chars, username is hashed using global replace
         result = anonymize_path(
-            "/Users/alice/Documents/myproject/src/main.py",
-            "alice", "user_abc12345", home="/Users/alice",
+            "/Users/alice/something",
+            "alice", "user_abc12345"
         )
-        assert result == "myproject/src/main.py"
+        assert result == "/Users/user_abc12345/something"
 
-    def test_downloads_prefix_stripped(self):
+    def test_bare_home_hashed(self):
         result = anonymize_path(
-            "/Users/alice/Downloads/file.zip",
-            "alice", "user_abc12345", home="/Users/alice",
+            "/Users/s/somedir/file.py",
+            "s", "user_abc12345", home="/Users/s",
         )
-        assert result == "file.zip"
+        assert result == "/Users/user_abc12345/somedir/file.py"
 
-    def test_desktop_prefix_stripped(self):
+    def test_linux_home_path(self):
         result = anonymize_path(
-            "/Users/alice/Desktop/notes.txt",
-            "alice", "user_abc12345", home="/Users/alice",
+            "/home/s/Documents/project/file.py",
+            "s", "user_abc12345", home="/home/s",
         )
-        assert result == "notes.txt"
+        assert result == "/home/user_abc12345/Documents/project/file.py"
 
-    def test_bare_home_hashed(self):
+    def test_path_not_under_home(self):
         result = anonymize_path(
-            "/Users/alice/somedir/file.py",
-            "alice", "user_abc12345", home="/Users/alice",
+            "/var/log/syslog",
+            "s", "user_abc12345", home="/Users/s",
         )
-        assert result == "user_abc12345/somedir/file.py"
+        assert result == "/var/log/syslog"
 
-    def test_linux_home_path(self):
+    def test_windows_users_path(self):
         result = anonymize_path(
-            "/home/alice/Documents/project/file.py",
-            "alice", "user_abc12345", home="/home/alice",
+            r"C:\Users\bob\Documents\file.txt",
+            "bob", "user_abc12345",
         )
-        assert result == "project/file.py"
+        assert result == r"C:\Users\user_abc12345\Documents\file.txt"
 
-    def test_path_not_under_home(self):
+    def test_windows_users_path_double_backslashes(self):
         result = anonymize_path(
-            "/var/log/syslog",
-            "alice", "user_abc12345", home="/Users/alice",
+            r"\\Users\\bob\\Documents\\file.txt",
+            "bob", "user_abc12345",
         )
-        assert result == "/var/log/syslog"
+        assert result == r"\\Users\\user_abc12345\\Documents\\file.txt"
+
+    def test_windows_custom_home_path(self):
+        result = anonymize_path(
+            "C:\\custom_home\\bob\\project\\file.py",
+            "bob", "user_abc12345", home=r"C:\custom_home\bob",
+        )
+        assert result == "C:\\custom_home\\user_abc12345\\project\\file.py"
 
-    def test_fallback_users_replacement(self):
-        # Path with username not matching the prefix set
+    def test_msys2_custom_home_path(self):
         result = anonymize_path(
-            "/tmp/Users/alice/something",
-            "alice", "user_abc12345", home="/Users/alice",
+            "/c/custom_home/bob/project/file.py",
+            "bob", "user_abc12345", home=r"C:\custom_home\bob",
         )
-        # Falls through prefix matching, hits the fallback .replace
-        assert "user_abc12345" in result or "/tmp/" in result
+        assert result == "/c/custom_home/user_abc12345/project/file.py"
 
 
 # --- anonymize_text ---
@@ -109,40 +115,35 @@ def test_users_path_replaced(self):
             "File at /Users/alice/project/main.py",
             "alice", "user_abc12345",
         )
-        assert "/user_abc12345/project/main.py" in result
+        assert result == "File at /Users/user_abc12345/project/main.py"
 
     def test_home_path_replaced(self):
         result = anonymize_text(
             "File at /home/alice/project/main.py",
             "alice", "user_abc12345",
         )
-        assert "/user_abc12345/project/main.py" in result
+        assert result == "File at /home/user_abc12345/project/main.py"
 
     def test_hyphen_encoded_path(self):
         result = anonymize_text(
             "-Users-alice-Documents-myproject",
             "alice", "user_abc12345",
         )
-        assert "-Users-user_abc12345" in result
+        assert result == "-Users-user_abc12345-Documents-myproject"
 
     def test_temp_path(self):
-        # The hyphen-encoded path regex runs before the temp path regex,
-        # so the username gets replaced but claude-XXX may not trigger.
-        # The important thing is the username is anonymized.
         result = anonymize_text(
             "/private/tmp/claude-501/-Users-alice-Documents-proj/foo",
             "alice", "user_abc12345",
         )
-        assert "alice" not in result
-        assert "user_abc12345" in result
+        assert result == "/private/tmp/claude-501/-Users-user_abc12345-Documents-proj/foo"
 
     def test_bare_username_replaced(self):
         result = anonymize_text(
             "Hello alice, welcome back",
             "alice", "user_abc12345",
         )
-        assert "alice" not in result
-        assert "user_abc12345" in result
+        assert result == "Hello user_abc12345, welcome back"
 
     def test_short_username_not_replaced_bare(self):
         # Usernames < 4 chars should NOT be replaced as bare words
@@ -150,7 +151,7 @@ def test_short_username_not_replaced_bare(self):
             "Hello bob, welcome back",
             "bob", "user_abc12345",
         )
-        assert "bob" in result  # bare replacement skipped for short username
+        assert result == "Hello bob, welcome back"
 
     def test_short_username_path_still_replaced(self):
         # Even short usernames should be replaced in path contexts
@@ -158,7 +159,7 @@ def test_short_username_path_still_replaced(self):
             "File at /Users/bob/project",
             "bob", "user_abc12345",
         )
-        assert "/user_abc12345/project" in result
+        assert result == "File at /Users/user_abc12345/project"
 
 
 # --- Anonymizer class ---