diff --git a/data/languages/az/language_config.json b/data/languages/az/language_config.json
index 403e108b..37f84a8d 100644
--- a/data/languages/az/language_config.json
+++ b/data/languages/az/language_config.json
@@ -62,25 +62,5 @@
         "play_daily_like_app": "Wordle-ı hər gün tətbiq kimi oyna",
         "install": "Quraşdır",
         "close": "bağla"
-    },
-    "diacritic_map": {
-        "c": [
-            "ç"
-        ],
-        "o": [
-            "ö"
-        ],
-        "u": [
-            "ü"
-        ],
-        "g": [
-            "ğ"
-        ],
-        "i": [
-            "ı"
-        ],
-        "s": [
-            "ş"
-        ]
     }
 }
diff --git a/data/languages/bg/language_config.json b/data/languages/bg/language_config.json
index 758cc62e..751980d1 100644
--- a/data/languages/bg/language_config.json
+++ b/data/languages/bg/language_config.json
@@ -64,10 +64,5 @@
         "play_daily_like_app": "Играй Wordle всеки ден като приложение",
         "install": "Инсталирай",
         "close": "затвори"
-    },
-    "diacritic_map": {
-        "и": [
-            "й"
-        ]
     }
 }
diff --git a/data/languages/cs/language_config.json b/data/languages/cs/language_config.json
index 9b47191d..62fe53a3 100644
--- a/data/languages/cs/language_config.json
+++ b/data/languages/cs/language_config.json
@@ -40,8 +40,7 @@
             "á"
         ],
         "e": [
-            "é",
-            "ě"
+            "é"
         ],
         "i": [
             "í"
@@ -49,33 +48,8 @@
         "o": [
             "ó"
         ],
-        "u": [
-            "ú",
-            "ů"
-        ],
         "y": [
             "ý"
-        ],
-        "c": [
-            "č"
-        ],
-        "d": [
-            "ď"
-        ],
-        "n": [
-            "ň"
-        ],
-        "r": [
-            "ř"
-        ],
-        "s": [
-            "š"
-        ],
-        "t": [
-            "ť"
-        ],
-        "z": [
-            "ž"
         ]
     }
 }
diff --git a/data/languages/da/language_config.json b/data/languages/da/language_config.json
index 90430885..37439999 100644
--- a/data/languages/da/language_config.json
+++ b/data/languages/da/language_config.json
@@ -63,14 +63,5 @@
         "play_daily_like_app": "Spil Wordle dagligt som en app",
         "install": "Installer",
         "close": "luk"
-    },
-    "diacritic_map": {
-        "a": [
-            "å",
-            "æ"
-        ],
-        "o": [
-            "ø"
-        ]
     }
 }
diff --git a/data/languages/et/language_config.json b/data/languages/et/language_config.json
index d4d57cd4..cf842c05 100644
--- a/data/languages/et/language_config.json
+++ b/data/languages/et/language_config.json
@@ -63,23 +63,5 @@
         "play_daily_like_app": "Mängi Wordle't iga päev nagu rakendust",
         "install": "Paigalda",
         "close": "sulge"
-    },
-    "diacritic_map": {
-        "a": [
-            "ä"
-        ],
-        "o": [
-            "õ",
-            "ö"
-        ],
-        "u": [
-            "ü"
-        ],
-        "s": [
-            "š"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/fi/language_config.json b/data/languages/fi/language_config.json
index ad9d6c15..92593659 100644
--- a/data/languages/fi/language_config.json
+++ b/data/languages/fi/language_config.json
@@ -68,15 +68,10 @@
     },
     "diacritic_map": {
         "a": [
-            "à",
-            "ä",
-            "å"
+            "à"
         ],
         "e": [
             "é"
-        ],
-        "o": [
-            "ö"
         ]
     }
 }
diff --git a/data/languages/fo/language_config.json b/data/languages/fo/language_config.json
index 1ec1595c..71d3bc76 100644
--- a/data/languages/fo/language_config.json
+++ b/data/languages/fo/language_config.json
@@ -37,18 +37,13 @@
     },
     "diacritic_map": {
         "a": [
-            "á",
-            "æ"
+            "á"
         ],
         "i": [
             "í"
         ],
-        "d": [
-            "ð"
-        ],
         "o": [
-            "ó",
-            "ø"
+            "ó"
         ],
         "u": [
             "ú"
diff --git a/data/languages/hr/language_config.json b/data/languages/hr/language_config.json
index 77daa6e9..cd4b5cd8 100644
--- a/data/languages/hr/language_config.json
+++ b/data/languages/hr/language_config.json
@@ -63,20 +63,5 @@
         "play_daily_like_app": "Igraj Wordle svakodnevno kao aplikaciju",
         "install": "Instaliraj",
         "close": "zatvori"
-    },
-    "diacritic_map": {
-        "c": [
-            "ć",
-            "č"
-        ],
-        "d": [
-            "đ"
-        ],
-        "s": [
-            "š"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/hu/language_config.json b/data/languages/hu/language_config.json
index 0cd9ce0e..fe879ed4 100644
--- a/data/languages/hu/language_config.json
+++ b/data/languages/hu/language_config.json
@@ -75,14 +75,10 @@
             "í"
         ],
         "o": [
-            "ó",
-            "ö",
-            "ő"
+            "ó"
         ],
         "u": [
-            "ú",
-            "ü",
-            "ű"
+            "ú"
         ]
     }
 }
diff --git a/data/languages/is/language_config.json b/data/languages/is/language_config.json
index 511a0e56..c65dcab4 100644
--- a/data/languages/is/language_config.json
+++ b/data/languages/is/language_config.json
@@ -36,8 +36,7 @@
     },
     "diacritic_map": {
         "a": [
-            "á",
-            "æ"
+            "á"
         ],
         "e": [
             "é"
@@ -45,21 +44,14 @@
         "i": [
             "í"
         ],
-        "d": [
-            "ð"
-        ],
         "o": [
-            "ó",
-            "ö"
+            "ó"
         ],
         "u": [
             "ú"
         ],
         "y": [
             "ý"
-        ],
-        "t": [
-            "þ"
         ]
     }
 }
diff --git a/data/languages/lb/language_config.json b/data/languages/lb/language_config.json
index 987c7fbd..65ea55ec 100644
--- a/data/languages/lb/language_config.json
+++ b/data/languages/lb/language_config.json
@@ -36,12 +36,8 @@
         "text_3": "En neit Wuert gëtt all Dag disponibel! "
     },
     "diacritic_map": {
-        "a": [
-            "ä"
-        ],
         "e": [
-            "é",
-            "ë"
+            "é"
         ]
     }
 }
diff --git a/data/languages/lt/language_config.json b/data/languages/lt/language_config.json
index a92fdcf9..c494c260 100644
--- a/data/languages/lt/language_config.json
+++ b/data/languages/lt/language_config.json
@@ -34,30 +34,5 @@
         "text_2_2": "yra žodyje, bet ne teisingoje vietoje. ",
         "text_2_3": "nėra žodžio, kurį bandote atspėti. ",
         "text_3": "Kiekvieną dieną bus prieinamas naujas žodis! "
-    },
-    "diacritic_map": {
-        "a": [
-            "ą"
-        ],
-        "c": [
-            "č"
-        ],
-        "e": [
-            "ė",
-            "ę"
-        ],
-        "i": [
-            "į"
-        ],
-        "s": [
-            "š"
-        ],
-        "u": [
-            "ū",
-            "ų"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/ltg/language_config.json b/data/languages/ltg/language_config.json
index af632ae1..5ef93c5d 100644
--- a/data/languages/ltg/language_config.json
+++ b/data/languages/ltg/language_config.json
@@ -34,40 +34,5 @@
         "text_2_2": "is in the word, but not in the correct location.",
         "text_2_3": "is not present in the word you are trying to guess.",
         "text_3": "A new word will be available each day!"
-    },
-    "diacritic_map": {
-        "a": [
-            "ā"
-        ],
-        "c": [
-            "č"
-        ],
-        "e": [
-            "ē"
-        ],
-        "i": [
-            "ī"
-        ],
-        "k": [
-            "ķ"
-        ],
-        "l": [
-            "ļ"
-        ],
-        "n": [
-            "ņ"
-        ],
-        "o": [
-            "ō"
-        ],
-        "s": [
-            "š"
-        ],
-        "u": [
-            "ū"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/lv/language_config.json b/data/languages/lv/language_config.json
index 799d697b..4ff416ba 100644
--- a/data/languages/lv/language_config.json
+++ b/data/languages/lv/language_config.json
@@ -63,40 +63,5 @@
         "play_daily_like_app": "Spēlē Wordle katru dienu kā lietotni",
         "install": "Instalēt",
         "close": "aizvērt"
-    },
-    "diacritic_map": {
-        "a": [
-            "ā"
-        ],
-        "c": [
-            "č"
-        ],
-        "e": [
-            "ē"
-        ],
-        "g": [
-            "ģ"
-        ],
-        "i": [
-            "ī"
-        ],
-        "k": [
-            "ķ"
-        ],
-        "l": [
-            "ļ"
-        ],
-        "n": [
-            "ņ"
-        ],
-        "s": [
-            "š"
-        ],
-        "u": [
-            "ū"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/mk/language_config.json b/data/languages/mk/language_config.json
index 3d68e0b6..441529fb 100644
--- a/data/languages/mk/language_config.json
+++ b/data/languages/mk/language_config.json
@@ -64,13 +64,5 @@
         "play_daily_like_app": "Играј Wordle секојдневно како апликација",
         "install": "Инсталирај",
         "close": "затвори"
-    },
-    "diacritic_map": {
-        "г": [
-            "ѓ"
-        ],
-        "к": [
-            "ќ"
-        ]
     }
 }
diff --git a/data/languages/mn/language_config.json b/data/languages/mn/language_config.json
index f121a495..627e2b9a 100644
--- a/data/languages/mn/language_config.json
+++ b/data/languages/mn/language_config.json
@@ -35,13 +35,5 @@
         "text_2_2": "гэдэг үгэнд байгаа боловч зөв байршилд байдаггүй. ",
         "text_2_3": "таах гэж байгаа үгэндээ байхгүй байна. ",
         "text_3": "Өдөр бүр шинэ үг бэлэн болно! "
-    },
-    "diacritic_map": {
-        "и": [
-            "й"
-        ],
-        "е": [
-            "ё"
-        ]
     }
 }
diff --git a/data/languages/pl/language_config.json b/data/languages/pl/language_config.json
index be22dc20..00d155f0 100644
--- a/data/languages/pl/language_config.json
+++ b/data/languages/pl/language_config.json
@@ -66,34 +66,13 @@
     },
     "diacritic_map": {
         "c": [
-            "ç",
-            "ć"
+            "ç"
         ],
         "o": [
-            "ó",
             "ö"
         ],
         "u": [
             "ü"
-        ],
-        "a": [
-            "ą"
-        ],
-        "e": [
-            "ę"
-        ],
-        "l": [
-            "ł"
-        ],
-        "n": [
-            "ń"
-        ],
-        "s": [
-            "ś"
-        ],
-        "z": [
-            "ź",
-            "ż"
         ]
     }
 }
diff --git a/data/languages/ro/language_config.json b/data/languages/ro/language_config.json
index 2f92cead..81e59f19 100644
--- a/data/languages/ro/language_config.json
+++ b/data/languages/ro/language_config.json
@@ -63,20 +63,5 @@
         "play_daily_like_app": "Joacă Wordle zilnic ca o aplicație",
         "install": "Instalează",
         "close": "închide"
-    },
-    "diacritic_map": {
-        "a": [
-            "â",
-            "ă"
-        ],
-        "i": [
-            "î"
-        ],
-        "s": [
-            "ș"
-        ],
-        "t": [
-            "ț"
-        ]
     }
 }
diff --git a/data/languages/ru/language_config.json b/data/languages/ru/language_config.json
index 15ef3661..d5c2ab4d 100644
--- a/data/languages/ru/language_config.json
+++ b/data/languages/ru/language_config.json
@@ -66,9 +66,6 @@
         "close": "закрыть"
     },
     "diacritic_map": {
-        "и": [
-            "й"
-        ],
         "е": [
             "ё"
         ]
diff --git a/data/languages/sk/language_config.json b/data/languages/sk/language_config.json
index 73952f11..ded984b4 100644
--- a/data/languages/sk/language_config.json
+++ b/data/languages/sk/language_config.json
@@ -76,39 +76,13 @@
             "í"
         ],
         "o": [
-            "ó",
-            "ô"
+            "ó"
         ],
         "u": [
             "ú"
         ],
         "y": [
             "ý"
-        ],
-        "c": [
-            "č"
-        ],
-        "d": [
-            "ď"
-        ],
-        "l": [
-            "ĺ",
-            "ľ"
-        ],
-        "n": [
-            "ň"
-        ],
-        "r": [
-            "ŕ"
-        ],
-        "s": [
-            "š"
-        ],
-        "t": [
-            "ť"
-        ],
-        "z": [
-            "ž"
         ]
     }
 }
diff --git a/data/languages/sl/language_config.json b/data/languages/sl/language_config.json
index 90608edd..ba03ab3f 100644
--- a/data/languages/sl/language_config.json
+++ b/data/languages/sl/language_config.json
@@ -34,16 +34,5 @@
         "text_2_2": "je v besedi, vendar ne na pravi lokaciji. ",
         "text_2_3": "ni prisotna v besedi, ki jo poskušate uganiti. ",
         "text_3": "Vsak dan bo na voljo nova beseda! "
-    },
-    "diacritic_map": {
-        "c": [
-            "č"
-        ],
-        "s": [
-            "š"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/sq/language_config.json b/data/languages/sq/language_config.json
index cbc8b8a0..bd281a5e 100644
--- a/data/languages/sq/language_config.json
+++ b/data/languages/sq/language_config.json
@@ -51,13 +51,5 @@
         "search_language": "Kërko gjuhën...",
         "definition": "Përkufizimi",
         "look_up_on_wiktionary": "Kërko në Wiktionary"
-    },
-    "diacritic_map": {
-        "c": [
-            "ç"
-        ],
-        "e": [
-            "ë"
-        ]
     }
 }
diff --git a/data/languages/sv/language_config.json b/data/languages/sv/language_config.json
index c675023d..7326ce6c 100644
--- a/data/languages/sv/language_config.json
+++ b/data/languages/sv/language_config.json
@@ -63,14 +63,5 @@
         "play_daily_like_app": "Spela Wordle dagligen som en app",
         "install": "Installera",
         "close": "stäng"
-    },
-    "diacritic_map": {
-        "a": [
-            "ä",
-            "å"
-        ],
-        "o": [
-            "ö"
-        ]
     }
 }
diff --git a/data/languages/tk/language_config.json b/data/languages/tk/language_config.json
index 3bfc45c3..9961b2ee 100644
--- a/data/languages/tk/language_config.json
+++ b/data/languages/tk/language_config.json
@@ -34,31 +34,5 @@
         "text_2_2": "sözünde, ýöne dogry ýerde däl. ",
         "text_2_3": "çaklamaga synanyşýan sözüňizde ýok. ",
         "text_3": "Her gün täze söz bolar! "
-    },
-    "diacritic_map": {
-        "a": [
-            "ä"
-        ],
-        "c": [
-            "ç"
-        ],
-        "o": [
-            "ö"
-        ],
-        "u": [
-            "ü"
-        ],
-        "y": [
-            "ý"
-        ],
-        "n": [
-            "ň"
-        ],
-        "s": [
-            "ş"
-        ],
-        "z": [
-            "ž"
-        ]
     }
 }
diff --git a/data/languages/tr/language_config.json b/data/languages/tr/language_config.json
index 33481bcd..2ae088ab 100644
--- a/data/languages/tr/language_config.json
+++ b/data/languages/tr/language_config.json
@@ -63,25 +63,5 @@
         "play_daily_like_app": "Wordle'ı her gün bir uygulama gibi oyna",
         "install": "Yükle",
         "close": "kapat"
-    },
-    "diacritic_map": {
-        "c": [
-            "ç"
-        ],
-        "o": [
-            "ö"
-        ],
-        "u": [
-            "ü"
-        ],
-        "g": [
-            "ğ"
-        ],
-        "i": [
-            "ı"
-        ],
-        "s": [
-            "ş"
-        ]
     }
 }
diff --git a/data/languages/uk/language_config.json b/data/languages/uk/language_config.json
index ed648290..827485e4 100644
--- a/data/languages/uk/language_config.json
+++ b/data/languages/uk/language_config.json
@@ -63,13 +63,5 @@
         "play_daily_like_app": "Грайте у Wordle щодня як у додаток",
         "install": "Встановити",
         "close": "закрити"
-    },
-    "diacritic_map": {
-        "и": [
-            "й"
-        ],
-        "і": [
-            "ї"
-        ]
     }
 }
diff --git a/scripts/fix_diacritic_maps.py b/scripts/fix_diacritic_maps.py
new file mode 100644
index 00000000..4c7c0080
--- /dev/null
+++ b/scripts/fix_diacritic_maps.py
@@ -0,0 +1,159 @@
+#!/usr/bin/env python3
+"""Fix diacritic_maps that incorrectly normalize distinct alphabet letters.
+
+Rule: if a character has its own key on the keyboard, it's a distinct letter
+and should NOT be in the diacritic_map (the color algorithm would wrongly
+treat it as equivalent to its base).
+
+Language-by-language decisions for the 43 maps added in 574ab2f:
+
+REMOVE ENTIRE MAP (all mapped chars are distinct alphabet letters):
+  az    - Azerbaijani: ç,ö,ü,ğ,ı,ş are all separate letters
+  bg    - Bulgarian: й is distinct from и
+  da    - Danish: å,æ,ø are 27th-29th letters
+  et    - Estonian: ä,õ,ö,ü,š,ž are distinct
+  hr    - Croatian: ć,č,đ,š,ž are distinct
+  lt    - Lithuanian: ą,č,ė,ę,į,š,ū,ų,ž are distinct
+  ltg   - Latgalian: ā,č,ē,ī,ķ,ļ,ņ,ō,š,ū,ž are distinct
+  lv    - Latvian: ā,č,ē,ģ,ī,ķ,ļ,ņ,š,ū,ž are distinct
+  mk    - Macedonian: ѓ,ќ are distinct
+  mn    - Mongolian: й,ё are distinct
+  ro    - Romanian: â,î,ă,ș,ț are distinct
+  sl    - Slovenian: č,š,ž are distinct
+  sq    - Albanian: ç,ë are distinct letters
+  sv    - Swedish: ä,ö,å are 27th-29th letters
+  tk    - Turkmen: all mapped chars are distinct
+  tr    - Turkish: ç,ğ,ı,ö,ş,ü are distinct (especially ı vs i!)
+  uk    - Ukrainian: й,ї are distinct
+
+REMOVE ON-KEYBOARD CHARS, KEEP OFF-KEYBOARD ACCENT VARIANTS:
+  cs    - Czech: remove háček letters (č,ď,ě,ň,ř,š,ť,ů,ž,ú on kb);
+          keep long vowels (á,é,í,ó,ý not on kb — legitimate variants)
+  fi    - Finnish: remove ä,ö,å (distinct, on kb);
+          keep à,é (foreign accent marks, not on kb)
+  fo    - Faroese: remove æ,ð,ø (distinct, on kb);
+          keep á,í,ó,ú,ý (accent variants, not on kb)
+  hu    - Hungarian: remove ö,ü,ő,ű (distinct, on kb);
+          keep á,é,í,ó,ú (long vowels, not on kb)
+  is    - Icelandic: remove æ,ð,ö,þ (distinct, on kb);
+          keep á,é,í,ó,ú,ý (accent variants, not on kb)
+  lb    - Luxembourgish: remove ä,ë (on kb);
+          keep é (not on kb)
+  pl    - Polish: remove ą,ć,ę,ł,ń,ó,ś,ź,ż (distinct, on kb);
+          keep ç,ö,ü (foreign chars, not on kb)
+  sk    - Slovak: remove háček letters + ô (on kb);
+          keep long vowels á,ä,é,í,ó,ú,ý (not on kb)
+
+KEEP ENTIRE MAP (chars are genuine accent/variant marks):
+  br    - Breton: ê,ù not on kb (keep); ñ on kb but acceptable for Breton
+  ckb   - Kurdish: hamza variants are interchangeable in Arabic script
+  eo    - Esperanto: circumflex letters (none on kb, all variants)
+  eu    - Basque: ç not on kb (keep); ñ on kb but is a variant in Basque
+  fa    - Persian: alef/hamza forms are genuinely interchangeable
+  fur   - Friulian: accent marks (only ç on kb, rest not)
+  fy    - Frisian: all accent variants, none on kb
+  ga    - Irish: fada vowels, none on kb
+  gd    - Scottish Gaelic: grave vowels, none on kb
+  hi    - Hindi: nukta variants, none on kb
+  ie    - Interlingue: accent vowels, none on kb
+  mi    - Māori: macrons on kb BUT macrons are length marks, not distinct
+          letters — ā is "long a" and matching a→ā is a useful convenience
+  nds   - Low German: umlauts on kb BUT Low German treats them as variants
+          (unlike standard German's distinct treatment in Finnish/Swedish)
+  oc    - Occitan: accent marks (only ç on kb)
+  qya   - Quenya: fictional lang, accents are variants (ñ,þ on kb but ok)
+  ru    - Russian: ё→е is universally accepted normalization (most Russian
+          text doesn't use ё); й→и is wrong but ё→е is so standard we keep it
+  tl    - Tagalog: ñ on kb but is a Spanish loanword accent, not distinct
+  ur    - Urdu: hamza variants are interchangeable in Arabic script
+
+SPECIAL CASE — partial fix needed:
+  ru    - Remove й→и mapping (distinct), keep ё→е (standard normalization)
+"""
+
+import json
+import os
+
+DATA = os.path.join(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "data", "languages"
+)
+
+# Languages to remove ENTIRE diacritic_map
+REMOVE_ALL = {
+    "az",
+    "bg",
+    "da",
+    "et",
+    "hr",
+    "lt",
+    "ltg",
+    "lv",
+    "mk",
+    "mn",
+    "ro",
+    "sl",
+    "sq",
+    "sv",
+    "tk",
+    "tr",
+    "uk",
+}
+
+# Languages to remove specific chars from map (char → set of variants to remove)
+REMOVE_SPECIFIC = {
+    "cs": {"ě", "ú", "ů", "č", "ď", "ň", "ř", "š", "ť", "ž"},
+    "fi": {"ä", "å", "ö"},
+    "fo": {"æ", "ð", "ø"},
+    "hu": {"ö", "ü", "ő", "ű"},
+    "is": {"æ", "ð", "ö", "þ"},
+    "lb": {"ä", "ë"},
+    "pl": {"ą", "ć", "ę", "ł", "ń", "ó", "ś", "ź", "ż"},
+    "sk": {"č", "ď", "ĺ", "ľ", "ň", "ô", "ŕ", "š", "ť", "ž"},
+    "ru": {"й"},  # Keep ё→е (standard Russian normalization)
+}
+
+
+def fix_language(lang_code):
+    cfg_path = os.path.join(DATA, lang_code, "language_config.json")
+    with open(cfg_path) as f:
+        cfg = json.load(f)
+
+    if "diacritic_map" not in cfg:
+        return False
+
+    if lang_code in REMOVE_ALL:
+        del cfg["diacritic_map"]
+        print(f"  {lang_code}: removed entire diacritic_map")
+    elif lang_code in REMOVE_SPECIFIC:
+        chars_to_remove = REMOVE_SPECIFIC[lang_code]
+        new_map = {}
+        for base, variants in cfg["diacritic_map"].items():
+            kept = [v for v in variants if v not in chars_to_remove]
+            if kept:
+                new_map[base] = kept
+        if new_map:
+            cfg["diacritic_map"] = new_map
+            print(f"  {lang_code}: removed {sorted(chars_to_remove)} from map, kept {new_map}")
+        else:
+            del cfg["diacritic_map"]
+            print(f"  {lang_code}: removed all chars → removed entire map")
+    else:
+        return False
+
+    with open(cfg_path, "w") as f:
+        json.dump(cfg, f, indent=4, ensure_ascii=False)
+        f.write("\n")
+    return True
+
+
+def main():
+    count = 0
+    for lang_code in sorted(REMOVE_ALL | set(REMOVE_SPECIFIC.keys())):
+        cfg_path = os.path.join(DATA, lang_code, "language_config.json")
+        if os.path.exists(cfg_path) and fix_language(lang_code):
+            count += 1
+    print(f"\nFixed {count} languages")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/test_diacritic_maps.py b/tests/test_diacritic_maps.py
new file mode 100644
index 00000000..96a50eee
--- /dev/null
+++ b/tests/test_diacritic_maps.py
@@ -0,0 +1,151 @@
+"""
+Tests for diacritic_map correctness.
+
+Core rule: if a character has its own key on the keyboard, it is a distinct
+letter and must NOT appear in the diacritic_map. Normalizing it would cause
+the color algorithm to wrongly treat it as equivalent to its base character.
+
+Example: Finnish has ö as a separate keyboard key and the 28th letter of the
+alphabet. Mapping ö→o would make the game show yellow/green for ö when the
+answer has o (or vice versa), which is wrong.
+
+Some languages intentionally have keyboard chars in their diacritic_map
+(e.g., German treats ö as a variant of o for Wordle purposes). These are
+in the ALLOWLIST below and were verified by the original language setup.
+"""
+
+import json
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent
+DATA_DIR = PROJECT_ROOT / "data"
+LANG_DIR = DATA_DIR / "languages"
+
+# Languages where keyboard chars in diacritic_map are INTENTIONAL.
+# These were set up by native speakers or verified pre-existing configs.
+# Any new language wanting this must be added here with justification.
+ALLOWLIST = {
+    # Pre-existing maps (verified before Nuxt migration):
+    "ar",  # Arabic: hamza/alef forms are interchangeable in Arabic script
+    "ca",  # Catalan: accents are stress marks, not distinct letters
+    "de",  # German: ä/ö/ü are treated as variants of a/o/u in Wordle
+    "el",  # Greek: accented vowels are same letter with stress mark
+    "es",  # Spanish: accented vowels are stress marks
+    "fr",  # French: accents are diacritical marks on base letters
+    "gl",  # Galician: same as Spanish/Portuguese
+    "it",  # Italian: accents are stress marks
+    "ko",  # Korean: jamo composition
+    "nb",  # Norwegian Bokmål: é/è/ó are accent variants (but æ/ø/å are NOT mapped)
+    "nl",  # Dutch: accents are stress marks
+    "nn",  # Norwegian Nynorsk: same as nb
+    "pt",  # Portuguese: accents are diacritical marks
+    "vi",  # Vietnamese: tone marks are diacritical
+    "yo",  # Yoruba: tone/dot marks are diacritical
+    # Post-migration additions with keyboard conflicts but intentionally kept:
+    "br",  # Breton: ñ on kb but treated as accent variant
+    "ckb",  # Kurdish: hamza variants are interchangeable
+    "eu",  # Basque: ñ on kb but is a variant
+    "fa",  # Persian: alef/hamza forms are interchangeable
+    "fur",  # Friulian: ç on kb but accent variants
+    "mi",  # Māori: macrons are length marks, not distinct letters
+    "nds",  # Low German: umlauts treated as variants (unlike Finnish/Swedish)
+    "oc",  # Occitan: ç on kb but accent variants
+    "qya",  # Quenya: fictional, accents are variants
+    "ru",  # Russian: ё→е is universally accepted normalization
+    "tl",  # Tagalog: ñ is a Spanish loanword accent
+    "ur",  # Urdu: hamza variants are interchangeable
+}
+
+
+def get_keyboard_chars(lang: str) -> set[str]:
+    """Get all characters that appear on the keyboard for a language."""
+    kb_chars: set[str] = set()
+
+    # Try dedicated keyboard file
+    kb_path = LANG_DIR / lang / f"{lang}_keyboard.json"
+    kb = None
+    if kb_path.exists():
+        kb = json.loads(kb_path.read_text())
+
+    # Fall back to keyboard in language_config
+    if not kb:
+        cfg_path = LANG_DIR / lang / "language_config.json"
+        if cfg_path.exists():
+            cfg = json.loads(cfg_path.read_text())
+            kb = cfg.get("keyboard")
+
+    if not kb:
+        return kb_chars
+
+    # Handle both array format and layouts format
+    if isinstance(kb, list):
+        for row in kb:
+            if isinstance(row, list):
+                kb_chars.update(row)
+    elif isinstance(kb, dict):
+        layouts = kb.get("layouts", {})
+        for layout in layouts.values():
+            rows = layout.get("rows", layout) if isinstance(layout, dict) else layout
+            if isinstance(rows, list):
+                for row in rows:
+                    if isinstance(row, list):
+                        kb_chars.update(row)
+
+    # Remove control keys
+    kb_chars.discard("⇨")
+    kb_chars.discard("⌫")
+    return kb_chars
+
+
+def get_languages_with_diacritic_maps() -> list[str]:
+    """Get all language codes that have a diacritic_map."""
+    langs = []
+    for lang_dir in sorted(LANG_DIR.iterdir()):
+        if not lang_dir.is_dir():
+            continue
+        cfg_path = lang_dir / "language_config.json"
+        if not cfg_path.exists():
+            continue
+        cfg = json.loads(cfg_path.read_text())
+        if cfg.get("diacritic_map"):
+            langs.append(lang_dir.name)
+    return langs
+
+
+LANGUAGES_WITH_MAPS = get_languages_with_diacritic_maps()
+
+
+class TestDiacriticMapCorrectness:
+    """Ensure diacritic_maps don't normalize distinct alphabet letters."""
+
+    @pytest.mark.parametrize("lang", LANGUAGES_WITH_MAPS)
+    def test_no_keyboard_chars_in_diacritic_map(self, lang):
+        """Characters with their own keyboard key should not be in diacritic_map.
+
+        If a character has its own key, it's a distinct letter in that language.
+        Normalizing it would cause wrong tile colors (e.g., ö showing yellow
+        when the answer has o in Finnish).
+
+        Allowlisted languages have been verified as intentional.
+        """
+        if lang in ALLOWLIST:
+            pytest.skip(f"{lang}: allowlisted (keyboard chars in map are intentional)")
+
+        cfg = json.loads((LANG_DIR / lang / "language_config.json").read_text())
+        dmap = cfg.get("diacritic_map", {})
+        kb_chars = get_keyboard_chars(lang)
+
+        if not kb_chars:
+            pytest.skip(f"{lang}: no keyboard data")
+
+        # Find diacritic chars that are also keyboard keys
+        diacritic_chars = {v for variants in dmap.values() for v in variants}
+        conflicts = diacritic_chars & kb_chars
+
+        assert not conflicts, (
+            f"{lang}: diacritic_map contains keyboard characters {sorted(conflicts)}. "
+            f"These are distinct letters and should NOT be normalized. "
+            f"If this is intentional, add '{lang}' to ALLOWLIST in this test with justification."
+        )