diff --git a/html/early.js b/html/early.js
index 6e9b490..f7cec98 100644
--- a/html/early.js
+++ b/html/early.js
@@ -583,16 +583,54 @@ function get_history() {
     }
     historyQueued.resolve();
 }
+function handleJsonWorker(e) {
+    const url = e.data.url;
+    //console.log("url finished: " + url);
+    const defer = g.jwr[url];
+    delete g.jwr[url];
+
+    defer.resolve(e.data.json);
+};
+
+function jsonGetWorker(url) {
+    const defer = jQuery.Deferred();
+    g.jwr[url] = defer;
+    const wid = g.jsonGetId++ % g.jsonWorker.length;
+    //console.log(`using worker ${wid}`);
+    g.jsonWorker[wid].postMessage(url);
+
+    return defer;
+}
+
+g.jWorkers = 0;
+if (g.jWorkers) {
+    g.jwr = {};
+
+    g.jsonWorker = [];
+    g.jsonGetId = 0;
+
+    for (let i = 0; i < g.jWorkers; i++) {
+        const worker = new Worker("jsonWorker.js");
+        g.jsonWorker.push(worker);
+        worker.onmessage = handleJsonWorker;
+    }
+
+}
 
 function get_history_item(i) {
     let request;
 
     if (HistoryChunks) {
-        let filename = chunkNames[i];
-        request = jQuery.ajax({ url: 'chunks/' + filename,
-            timeout: historyTimeout * 1000,
-            dataType: 'json'
-        });
+        const url = 'chunks/' + chunkNames[i];
+
+        if (g.jWorkers) {
+            request = jsonGetWorker(url);
+        } else {
+            request = jQuery.ajax({ url: url,
+                timeout: historyTimeout * 1000,
+                dataType: 'json'
+            });
+        }
     } else {
 
         request = jQuery.ajax({ url: 'data/history_' + i + '.json',
@@ -608,6 +646,7 @@ function get_history_item(i) {
         .fail(function(jqxhr, status, error) {
             jQuery("#loader_progress").attr('value',++HistoryItemsLoaded);
         });
+
     deferHistory.push(request);
 }
 
diff --git a/html/jsonWorker.js b/html/jsonWorker.js
new file mode 100644
index 0000000..9209adc
--- /dev/null
+++ b/html/jsonWorker.js
@@ -0,0 +1,15 @@
+
+onmessage = (e) => {
+    const url = e.data;
+    fetch(new Request(url))
+        .then((response) => {
+            if (!response.ok) {
+                throw new Error(`HTTP error! Status: ${response.status} ${response.url}`);
+            }
+            return response.json();
+        })
+        .then((data) => {
+            //console.log("worker posting data with url: " + url);
+            postMessage({ url: url, json: data });
+        })
+};
diff --git a/html/layers.js b/html/layers.js
index 26deeee..42570b5 100644
--- a/html/layers.js
+++ b/html/layers.js
@@ -22,7 +22,7 @@ function createBaseLayers() {
     let us = new ol.Collection();
     let europe = new ol.Collection();
 
-    const tileTransition = onMobile ? 0 : 150;
+    const tileTransition = onMobile ? 0 : 0;
 
     if (loStore['customTiles'] != undefined) {
         custom_layers.push(new ol.layer.Tile({
diff --git a/html/script.js b/html/script.js
index 56266c0..b8c5308 100644
--- a/html/script.js
+++ b/html/script.js
@@ -508,7 +508,7 @@ function afterFirstFetch() {
         }
 
         console.timeEnd('afterFirstFetch()');
-    }, 150);
+    }, 50);
 }
 
 let debugFetch = false;
@@ -720,29 +720,32 @@ function initialize() {
 
         processQueryToggles();
 
-        jQuery.when(historyQueued).done(push_history);
-
-        if (nHistoryItems) {
-            jQuery.when(historyLoaded).done(afterHistoryLoad);
-        } else {
-            afterHistoryLoad();
-        }
+        tryStartPage();
     });
 }
-function afterHistoryLoad() {
-    if (!heatmap)
-        jQuery("#loader").hide();
 
-    if (!zstdDecode) {
+function doHistory() {
+
+    jQuery.when(historyQueued).done(push_history);
+
+    if (nHistoryItems) {
+        jQuery.when(historyLoaded).done(startPage);
+    } else {
         startPage();
+    }
+}
+
+function tryStartPage() {
+    if (!zstdDecode) {
+        doHistory();
     } else {
         try {
             zstddec.promise.then(function() {
-                startPage();
+                doHistory();
             });
         } catch (e) {
             webAssemblyFail(e);
-            startPage();
+            doHistory();
         }
     }
 }
@@ -1670,6 +1673,29 @@ jQuery('#selected_altitude_geom1')
         jQuery('#imageConfigLink').text(imageConfigText)
         jQuery('#imageConfigHeader').show();
     }
+
+
+    if (!globeIndex) {
+        jQuery("#lastLeg_cb").parent().hide();
+        jQuery('#show_trace').hide();
+    }
+    if (globeIndex) {
+        toggleTableInView('enable');
+        if (icaoFilter) {
+            toggleTableInView('disable');
+        }
+    } else {
+        jQuery('#V').show();
+    }
+
+    if (hideButtons) {
+        jQuery('#header_top').hide();
+        jQuery('#header_side').hide();
+        jQuery('#tabs').hide();
+        jQuery('#filterButton').hide();
+        jQuery('.ol-control').hide();
+        jQuery('.ol-attribution').show();
+    }
 }
 
 function initLegend(colors) {
@@ -1909,8 +1935,6 @@ function parseHistory() {
                 plane.last_message_time -= 999;
             }
         }
-        refreshFeatures();
-        TAR.planeMan.refresh();
     }
 
     console.timeEnd("Loaded aircraft tracks from History");
@@ -1982,7 +2006,7 @@ function setIntervalTimers() {
     }
     if (receiverJson && receiverJson.outlineJson) {
         timers.drawOutline = window.setInterval(drawOutlineJson, actualOutline.refresh);
-        drawOutlineJson();
+        setTimeout(drawOutlineJson, 50);
     }
 
     if (aiscatcher_server) {
@@ -2003,7 +2027,12 @@ function setIntervalTimers() {
     }
 
     timersActive = true;
-    fetchData();
+
+    setTimeout(fetchData, 5);
+
+    updateVisible();
+    mapRefresh();
+
     // in case the visibility changed while this was running
     handleVisibilityChange();
 }
@@ -2013,28 +2042,8 @@ let dstring;
 let dresult;
 
 function startPage() {
-
-    if (!globeIndex) {
-        jQuery("#lastLeg_cb").parent().hide();
-        jQuery('#show_trace').hide();
-    }
-    if (globeIndex) {
-        toggleTableInView('enable');
-        if (icaoFilter) {
-            toggleTableInView('disable');
-        }
-    } else {
-        jQuery('#V').show();
-    }
-
-    if (hideButtons) {
-        jQuery('#header_top').hide();
-        jQuery('#header_side').hide();
-        jQuery('#tabs').hide();
-        jQuery('#filterButton').hide();
-        jQuery('.ol-control').hide();
-        jQuery('.ol-attribution').show();
-    }
+    if (!heatmap)
+        jQuery("#loader").hide();
 
     changeZoom("init");
     changeCenter("init");
@@ -2076,9 +2085,7 @@ function startPage() {
     if (pTracks)
         setTimeout(TAR.planeMan.refresh, 10000);
 
-    window.addEventListener("beforeunload", function (event) {
-        clearIntervalTimers();
-    });
+    window.addEventListener("beforeunload", clearIntervalTimers);
 
     if (heatmap || replay || showTrace || pTracks || inhibitFetch) {
         afterFirstFetch();
@@ -5489,10 +5496,13 @@ function refresh(redraw) {
     // before planeman refresh / mapRefresh
     updateVisible();
 
+    mapRefresh(redraw);
+
     //console.time("refreshTable");
     TAR.planeMan.refresh();
     //console.timeEnd("refreshTable");
-    mapRefresh(redraw);
+
+
     refreshSelected();
     refreshHighlighted();