diff --git a/wled00/FX.h b/wled00/FX.h
index af79c514..f20b1caf 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -43,20 +43,21 @@ bool strip_uses_global_leds(void) __attribute__((pure));  // WLEDMM implemented
 #endif
 
 /* Not used in all effects yet */
-#define FPS_UNLIMITED    249
+#define FPS_UNLIMITED    250
+#define FPS_UNLIMITED_AC 0   // WLEDMM upstream uses "0 fps" for unlimited. We support both ways
 #if defined(ARDUINO_ARCH_ESP32) && defined(WLEDMM_FASTPATH)   // WLEDMM go faster on ESP32
-#define WLED_FPS         120
-#define FRAMETIME_FIXED  (strip.getFrameTime() < 10 ? 12 : 24)
-#define WLED_FPS_SLOW         60
-#define FRAMETIME_FIXED_SLOW  (15)    // = 66 FPS => 1000/66
 #define FRAMETIME        strip.getFrameTime()
 #define MIN_SHOW_DELAY   (max(2, (_frametime*5)/8))    // WLEDMM support higher framerates (up to 250fps) -- 5/8 = 62%
+#define WLED_FPS         120
+#define WLED_FPS_SLOW    60
+#define FRAMETIME_FIXED  24                                // used in Blurz, Freqmap, Scrolling text 
+//#define FRAMETIME_FIXED  (strip.getFrameTime() < 10 ? 12 : 24)
+#define FRAMETIME_FIXED_SLOW  (15)    // = 66 FPS => 1000/66 // used in Solid, Colortwinkles, Candle
 #else
 #define WLED_FPS         42
 #define FRAMETIME_FIXED  (1000/WLED_FPS)
-#define WLED_FPS_SLOW         42
+#define WLED_FPS_SLOW    42
 #define FRAMETIME_FIXED_SLOW  (1000/WLED_FPS_SLOW)
-//#define FRAMETIME        _frametime
 #define FRAMETIME        strip.getFrameTime()
 //#define MIN_SHOW_DELAY   (_frametime < 16 ? 8 : 15)  // Upstream legacy
 #define MIN_SHOW_DELAY   (_frametime < 16 ? (_frametime <8? (_frametime <7? (_frametime <6 ? 2 :3) :4) : 8) : 15)    // WLEDMM support higher framerates (up to 250fps)
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 44642689..5ad6583c 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -1877,15 +1877,15 @@ void WS2812FX::service() {
   #if defined(ARDUINO_ARCH_ESP32) && defined(WLEDMM_FASTPATH)   // WLEDMM go faster on ESP32
   //if (_suspend) return;
   if (elapsed < 2) return;                                                       // keep wifi alive
-  if ( !_triggered && (_targetFps < FPS_UNLIMITED) && (_targetFps > 0)) {
+  if ( !_triggered && (_targetFps != FPS_UNLIMITED) && (_targetFps != FPS_UNLIMITED_AC)) {
     if (elapsed < MIN_SHOW_DELAY) return;                                        // WLEDMM too early for service
   }
   #else  // legacy
-  if (elapsed < MIN_SHOW_DELAY) return;
+  if (nowUp - _lastShow < MIN_SHOW_DELAY) return;
   #endif
 
   bool doShow = false;
-  unsigned speedLimit = (_targetFps < FPS_UNLIMITED) ? (0.85f * FRAMETIME) : 1;      // WLEDMM lower limit for effect frametime
+  unsigned speedLimit = (_targetFps != FPS_UNLIMITED) && (_targetFps != FPS_UNLIMITED_AC) ? (0.85f * FRAMETIME) : 1;      // WLEDMM minimum for effect frametime
 
   _isServicing = true;
   _segment_index = 0;
@@ -2120,10 +2120,10 @@ uint16_t WS2812FX::getFps() const {
 }
 
 void WS2812FX::setTargetFps(uint8_t fps) {
-  if (fps > 0 && fps <= 251) _targetFps = fps;  // WLEDMM allow higher framerates
-  _frametime = 1000 / _targetFps;
-  if (_frametime < 1) _frametime = 1;           // WLEDMM better safe than sorry
-  if (fps >= FPS_UNLIMITED) _frametime = 3;     // WLEDMM unlimited mode
+  if (fps <= 251) _targetFps = fps;  // WLEDMM allow higher framerates
+  if (fps > 0) _frametime = 1000 / _targetFps;
+  else _frametime = 2;                          // AC WLED compatibility
+  if (fps >= FPS_UNLIMITED) _frametime = 2;     // WLEDMM unlimited mode
 }
 
 void WS2812FX::setMode(uint8_t segid, uint8_t m) {
diff --git a/wled00/data/settings_leds.htm b/wled00/data/settings_leds.htm
index 35d32321..7deff3a4 100644
--- a/wled00/data/settings_leds.htm
+++ b/wled00/data/settings_leds.htm
@@ -166,7 +166,8 @@
 
 			gId('ampwarning').style.display = (d.Sf.MA.value > 7200) ? 'inline':'none';
 
-			gId('fpswarning').style.display = (d.Sf.FR.value > 69) ? 'block':'none'; // WLEDMM
+			gId('fpsNone').style.display = ((d.Sf.FR.value == 0) || (d.Sf.FR.value > 249))? 'block':'none'; // WLEDMM
+			gId('fpswarning').style.display = (d.Sf.FR.value > 69) || (d.Sf.FR.value == 0) ? 'block':'none'; // WLEDMM
 			gId('fpshelp1').style.display = ((d.Sf.FR.value > 80) && (d.Sf.FR.value < 132)) ? 'block':'none'; // WLEDMM
 			gId('fpshelp2').style.display = ((d.Sf.FR.value > 132) && (d.Sf.FR.value < 196)) ? 'block':'none'; // WLEDMM
 			gId('fpshelp3').style.display = (d.Sf.FR.value > 196) ? 'block':'none'; // WLEDMM
@@ -732,7 +733,8 @@ Length: <input type="number" name="XC${i}" id="xc${i}" class="l" min="1" max="65
 			<option value="2">Linear (never wrap)</option>
 			<option value="3">None (not recommended)</option>
 		</select><br>
-		Target refresh rate: <input type="number" class="s" min="1" max="250" name="FR" oninput="UI()" required> FPS
+		Target refresh rate: <input type="number" class="s" min="0" max="250" name="FR" oninput="UI()" required> FPS
+		<div id="fpsNone" style="color:green; display: none;"><b>unlimited FPS mode.</b><br></div>
 		<div id="fpswarning" style="color:GoldenRod; display: none;">
 			&#9888; WLED may become unstable above 70 fps.<br>
 			To protect your setup,