diff --git a/wled00/FX.h b/wled00/FX.h
index 44c57d07..589a7005 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -24,6 +24,8 @@
   Modified for WLED
 */
 
+#include "wled.h"
+
 #ifndef WS2812FX_h
 #define WS2812FX_h
 
@@ -847,7 +849,11 @@ class WS2812FX {
 
     void
       blendPixelColor(uint16_t n, uint32_t color, uint8_t blend),
-      startTransition(uint8_t oldBri, uint32_t oldCol, uint16_t dur, uint8_t segn, uint8_t slot);
+      startTransition(uint8_t oldBri, uint32_t oldCol, uint16_t dur, uint8_t segn, uint8_t slot),
+      deserializeMap(void);
+
+    uint16_t* customMappingTable = nullptr;
+    uint16_t  customMappingSize  = 0;
     
     uint32_t _lastPaletteChange = 0;
     uint32_t _lastShow = 0;
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 8c1681a3..aef500ce 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -27,27 +27,26 @@
 #include "FX.h"
 #include "palettes.h"
 
-//enable custom per-LED mapping. This can allow for better effects on matrices or special displays
-//#define WLED_CUSTOM_LED_MAPPING
-
-#ifdef WLED_CUSTOM_LED_MAPPING
-//this is just an example (30 LEDs). It will first set all even, then all uneven LEDs.
-const uint16_t customMappingTable[] = {
-  0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28,
-  1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29};
-
-//another example. Switches direction every 5 LEDs.
-/*const uint16_t customMappingTable[] = {
-  0, 1, 2, 3, 4, 9, 8, 7, 6, 5, 10, 11, 12, 13, 14,
-  19, 18, 17, 16, 15, 20, 21, 22, 23, 24, 29, 28, 27, 26, 25};*/
-
-const uint16_t customMappingSize = sizeof(customMappingTable)/sizeof(uint16_t); //30 in example
-#endif
-
 #ifndef PWM_INDEX
 #define PWM_INDEX 0
 #endif
 
+/*
+  Custom per-LED mapping has moved!
+
+  Create a file "ledmap.json" using the edit page.
+
+  this is just an example (30 LEDs). It will first set all even, then all uneven LEDs.
+  {"map":[
+  0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28,
+  1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29]}
+
+  another example. Switches direction every 5 LEDs.
+  {"map":[
+  0, 1, 2, 3, 4, 9, 8, 7, 6, 5, 10, 11, 12, 13, 14,
+  19, 18, 17, 16, 15, 20, 21, 22, 23, 24, 29, 28, 27, 26, 25]
+*/
+
 void WS2812FX::init(bool supportWhite, uint16_t countPixels, bool skipFirst)
 {
   if (supportWhite == _useRgbw && countPixels == _length && _skipFirstMode == skipFirst) return;
@@ -63,6 +62,8 @@ void WS2812FX::init(bool supportWhite, uint16_t countPixels, bool skipFirst)
     _lengthRaw += LED_SKIP_AMOUNT;
   }
 
+  deserializeMap();
+
   bus->Begin((NeoPixelType)ty, _lengthRaw);
   
   _segments[0].start = 0;
@@ -189,9 +190,7 @@ void WS2812FX::setPixelColor(uint16_t i, byte r, byte g, byte b, byte w)
       int16_t indexSet = realIndex + (reversed ? -j : j);
       int16_t indexSetRev = indexSet;
       if (reverseMode) indexSetRev = REV(indexSet);
-      #ifdef WLED_CUSTOM_LED_MAPPING
       if (indexSet < customMappingSize) indexSet = customMappingTable[indexSet];
-      #endif
       if (indexSetRev >= SEGMENT.start && indexSetRev < SEGMENT.stop) {
         bus->SetPixelColor(indexSet + skip, col);
         if (IS_MIRROR) { //set the corresponding mirrored pixel
@@ -205,9 +204,7 @@ void WS2812FX::setPixelColor(uint16_t i, byte r, byte g, byte b, byte w)
     }
   } else { //live data, etc.
     if (reverseMode) i = REV(i);
-    #ifdef WLED_CUSTOM_LED_MAPPING
     if (i < customMappingSize) i = customMappingTable[i];
-    #endif
     bus->SetPixelColor(i + skip, col);
   }
   if (skip && i == 0) {
@@ -482,9 +479,7 @@ uint32_t WS2812FX::getPixelColor(uint16_t i)
 {
   i = realPixelIndex(i);
   
-  #ifdef WLED_CUSTOM_LED_MAPPING
   if (i < customMappingSize) i = customMappingTable[i];
-  #endif
 
   if (_skipFirstMode) i += LED_SKIP_AMOUNT;
   
@@ -1006,6 +1001,31 @@ void WS2812FX::setRgbwPwm(void) {
 void WS2812FX::setRgbwPwm() {}
 #endif
 
+//load custom mapping table from JSON file
+void WS2812FX::deserializeMap(void) {
+  if (!WLED_FS.exists("/ledmap.json")) return;
+  DynamicJsonDocument doc(JSON_BUFFER_SIZE);  // full sized buffer for larger maps
+
+  DEBUG_PRINTLN(F("Reading LED map from /ledmap.json..."));
+
+  if (!readObjectFromFile("/ledmap.json", nullptr, &doc)) return; //if file does not exist just exit
+
+  if (customMappingTable != nullptr) {
+    delete[] customMappingTable;
+    customMappingTable = nullptr;
+    customMappingSize = 0;
+  }
+
+  JsonArray map = doc[F("map")];
+  if (!map.isNull() && map.size()) {  // not an empty map
+    customMappingSize  = map.size();
+    customMappingTable = new uint16_t[customMappingSize];
+    for (uint16_t i=0; i<customMappingSize; i++) {
+      customMappingTable[i] = (uint16_t) map[i];
+    }
+  }
+}
+
 //gamma 2.8 lookup table used for color correction
 byte gammaT[] = {
     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,