diff --git a/.changeset/always-on-distribution.md b/.changeset/always-on-distribution.md
new file mode 100644
index 0000000000..e6a06ec54d
--- /dev/null
+++ b/.changeset/always-on-distribution.md
@@ -0,0 +1,5 @@
+---
+"@hyperdx/app": patch
+---
+
+feat: always-on attribute distribution mode for Event Deltas
diff --git a/packages/app/src/components/DBDeltaChart.tsx b/packages/app/src/components/DBDeltaChart.tsx
index a64154a525..341db2bc82 100644
--- a/packages/app/src/components/DBDeltaChart.tsx
+++ b/packages/app/src/components/DBDeltaChart.tsx
@@ -18,10 +18,12 @@ import { useElementSize } from '@mantine/hooks';
 import { isAggregateFunction } from '@/ChartUtils';
 import { useQueriedChartConfig } from '@/hooks/useChartConfig';
 import { getFirstTimestampValueExpression } from '@/source';
+import { getChartColorError, getChartColorSuccess } from '@/utils';
 
 import { SQLPreview } from './ChartSQLPreview';
 import type { AddFilterFn } from './deltaChartUtils';
 import {
+  ALL_SPANS_COLOR,
   computeComparisonScore,
   flattenedKeyToFilterKey,
   getPropertyStatistics,
@@ -45,22 +47,32 @@ export type { AddFilterFn } from './deltaChartUtils';
 export default function DBDeltaChart({
   config,
   valueExpr,
-  xMin,
-  xMax,
-  yMin,
-  yMax,
+  xMin: rawXMin,
+  xMax: rawXMax,
+  yMin: rawYMin,
+  yMax: rawYMax,
   onAddFilter,
   spanIdExpression,
 }: {
   config: BuilderChartConfigWithDateRange;
   valueExpr: string;
-  xMin: number;
-  xMax: number;
-  yMin: number;
-  yMax: number;
+  xMin?: number | null;
+  xMax?: number | null;
+  yMin?: number | null;
+  yMax?: number | null;
   onAddFilter?: AddFilterFn;
   spanIdExpression?: string;
 }) {
+  // Derive whether a heatmap selection exists from nullable props
+  const hasSelection =
+    rawXMin != null && rawXMax != null && rawYMin != null && rawYMax != null;
+  // Safe numeric defaults so query builders always get valid values
+  // (outlier/inlier queries are gated by enabled:hasSelection)
+  const xMin = rawXMin ?? 0;
+  const xMax = rawXMax ?? 0;
+  const yMin = rawYMin ?? 0;
+  const yMax = rawYMax ?? 0;
+
   // Determine if the value expression uses aggregate functions
   const isAggregate = isAggregateFunction(valueExpr);
 
@@ -200,28 +212,60 @@ export default function DBDeltaChart({
     ];
   };
 
-  const { data: outlierData, error } = useQueriedChartConfig({
-    ...config,
-    with: buildWithClauses(true),
-    select: '*',
-    filters: buildFilters(true),
-    orderBy: [{ ordering: 'DESC', valueExpression: stableSampleExpr }],
-    limit: { limit: SAMPLE_SIZE },
-  });
-
-  const { data: inlierData } = useQueriedChartConfig({
-    ...config,
-    with: buildWithClauses(false),
-    select: '*',
-    filters: buildFilters(false),
-    orderBy: [{ ordering: 'DESC', valueExpression: stableSampleExpr }],
-    limit: { limit: SAMPLE_SIZE },
-  });
+  const {
+    data: outlierData,
+    error: outlierError,
+    isLoading: isOutlierLoading,
+  } = useQueriedChartConfig(
+    {
+      ...config,
+      with: buildWithClauses(true),
+      select: '*',
+      filters: buildFilters(true),
+      orderBy: [{ ordering: 'DESC', valueExpression: stableSampleExpr }],
+      limit: { limit: SAMPLE_SIZE },
+    },
+    { enabled: hasSelection },
+  );
+
+  const { data: inlierData, isLoading: isInlierLoading } =
+    useQueriedChartConfig(
+      {
+        ...config,
+        with: buildWithClauses(false),
+        select: '*',
+        filters: buildFilters(false),
+        orderBy: [{ ordering: 'DESC', valueExpression: stableSampleExpr }],
+        limit: { limit: SAMPLE_SIZE },
+      },
+      { enabled: hasSelection },
+    );
+
+  // When no selection exists, fetch all spans without any range filter
+  const {
+    data: allSpansData,
+    error: allSpansError,
+    isLoading: isAllSpansLoading,
+  } = useQueriedChartConfig(
+    {
+      ...config,
+      select: '*',
+      orderBy: [{ ordering: 'DESC', valueExpression: stableSampleExpr }],
+      limit: { limit: SAMPLE_SIZE },
+    },
+    { enabled: !hasSelection },
+  );
+
+  const isLoading = hasSelection
+    ? isOutlierLoading || isInlierLoading
+    : isAllSpansLoading;
+
+  const error = outlierError ?? allSpansError;
 
   // Column metadata for field classification (from ClickHouse response)
   const columnMeta = useMemo<{ name: string; type: string }[]>(
-    () => outlierData?.meta ?? inlierData?.meta ?? [],
-    [outlierData?.meta, inlierData?.meta],
+    () => outlierData?.meta ?? inlierData?.meta ?? allSpansData?.meta ?? [],
+    [outlierData?.meta, inlierData?.meta, allSpansData?.meta],
   );
 
   // Wrap onAddFilter to convert flattened dot-notation keys into ClickHouse bracket notation
@@ -233,24 +277,30 @@ export default function DBDeltaChart({
     [onAddFilter, columnMeta],
   );
 
-  // TODO: Is loading state
   const {
     visibleProperties,
     hiddenProperties,
     outlierValueOccurences,
     inlierValueOccurences,
   } = useMemo(() => {
+    // When no selection: use allSpans as "outlier" data and empty for inliers.
+    // The sort will rank by frequency (delta = count - 0 = count).
+    const actualOutlierData = hasSelection
+      ? (outlierData?.data ?? [])
+      : (allSpansData?.data ?? []);
+    const actualInlierData = hasSelection ? (inlierData?.data ?? []) : [];
+
     const {
       percentageOccurences: outlierValueOccurences,
       propertyOccurences: outlierPropertyOccurences,
       valueOccurences: outlierRawValueOccurences,
-    } = getPropertyStatistics(outlierData?.data ?? []);
+    } = getPropertyStatistics(actualOutlierData);
 
     const {
       percentageOccurences: inlierValueOccurences,
       propertyOccurences: inlierPropertyOccurences,
       valueOccurences: inlierRawValueOccurences,
-    } = getPropertyStatistics(inlierData?.data ?? []);
+    } = getPropertyStatistics(actualInlierData);
 
     // Get all the unique keys from the outliers
     let uniqueKeys = new Set([...outlierValueOccurences.keys()]);
@@ -308,7 +358,13 @@ export default function DBDeltaChart({
       outlierValueOccurences,
       inlierValueOccurences,
     };
-  }, [outlierData?.data, inlierData?.data, columnMeta]);
+  }, [
+    outlierData?.data,
+    inlierData?.data,
+    allSpansData?.data,
+    hasSelection,
+    columnMeta,
+  ]);
 
   const [activePage, setPage] = useState(1);
 
@@ -411,6 +467,71 @@ export default function DBDeltaChart({
         flexDirection: 'column',
       }}
     >
+      {/* Legend */}
+      <Flex gap="md" align="center" mb="xs" wrap="wrap">
+        {hasSelection ? (
+          <>
+            <Flex align="center" gap={4}>
+              <Box
+                w={10}
+                h={10}
+                style={{
+                  background: getChartColorError(),
+                  borderRadius: 2,
+                  flexShrink: 0,
+                }}
+              />
+              <Text size="xs" c="dimmed">
+                Selection
+              </Text>
+            </Flex>
+            <Flex align="center" gap={4}>
+              <Box
+                w={10}
+                h={10}
+                style={{
+                  background: getChartColorSuccess(),
+                  borderRadius: 2,
+                  flexShrink: 0,
+                }}
+              />
+              <Text size="xs" c="dimmed">
+                Background
+              </Text>
+            </Flex>
+          </>
+        ) : (
+          <>
+            <Flex align="center" gap={4}>
+              <Box
+                w={10}
+                h={10}
+                style={{
+                  background: ALL_SPANS_COLOR,
+                  borderRadius: 2,
+                  flexShrink: 0,
+                }}
+              />
+              <Text size="xs" c="dimmed">
+                All spans
+              </Text>
+            </Flex>
+            <Text size="xs" c="dimmed" fs="italic">
+              {isLoading
+                ? 'Loading\u2026'
+                : 'Select an area on the chart above to enable comparisons'}
+            </Text>
+          </>
+        )}
+      </Flex>
+      {/* Loading state */}
+      {isLoading && visibleOnPage.length === 0 && hiddenOnPage.length === 0 && (
+        <Flex align="center" justify="center" style={{ flex: 1 }}>
+          <Text size="sm" c="dimmed">
+            Loading attribute distributions\u2026
+          </Text>
+        </Flex>
+      )}
       {/* Primary fields */}
       {visibleOnPage.length > 0 && (
         <div
@@ -431,6 +552,7 @@ export default function DBDeltaChart({
               }
               onAddFilter={onAddFilter ? handleAddFilter : undefined}
               key={property}
+              hasSelection={hasSelection}
             />
           ))}
         </div>
@@ -448,7 +570,7 @@ export default function DBDeltaChart({
           labelPosition="left"
         />
       )}
-      {/* Lower-priority fields — separate grid so rows align independently */}
+      {/* Lower-priority fields - separate grid so rows align independently */}
       {hiddenOnPage.length > 0 && (
         <div
           style={{
@@ -468,6 +590,7 @@ export default function DBDeltaChart({
               }
               onAddFilter={onAddFilter ? handleAddFilter : undefined}
               key={key}
+              hasSelection={hasSelection}
             />
           ))}
         </div>
diff --git a/packages/app/src/components/PropertyComparisonChart.tsx b/packages/app/src/components/PropertyComparisonChart.tsx
index 2cad624304..69c5919f18 100644
--- a/packages/app/src/components/PropertyComparisonChart.tsx
+++ b/packages/app/src/components/PropertyComparisonChart.tsx
@@ -23,6 +23,7 @@ import {
 import { DBRowTableIconButton } from './DBTable/DBRowTableIconButton';
 import type { AddFilterFn } from './deltaChartUtils';
 import {
+  ALL_SPANS_COLOR,
   applyTopNAggregation,
   mergeValueStatisticsMaps,
   OTHER_BUCKET_COLOR,
@@ -127,11 +128,13 @@ export function PropertyComparisonChart({
   outlierValueOccurences,
   inlierValueOccurences,
   onAddFilter,
+  hasSelection = true,
 }: {
   name: string;
   outlierValueOccurences: Map<string, number>;
   inlierValueOccurences: Map<string, number>;
   onAddFilter?: AddFilterFn;
+  hasSelection?: boolean;
 }) {
   const mergedValueStatistics = mergeValueStatisticsMaps(
     outlierValueOccurences,
@@ -206,41 +209,47 @@ export function PropertyComparisonChart({
               />
               <Tooltip
                 content={<HDXBarChartTooltip title={name} />}
-                allowEscapeViewBox={{ x: false, y: true }}
+                allowEscapeViewBox={{ x: true, y: true }}
                 wrapperStyle={{ zIndex: 1000 }}
               />
               <Bar
                 dataKey="outlierCount"
-                name="Selection"
-                fill={getChartColorError()}
+                name={hasSelection ? 'Selection' : 'All spans'}
+                fill={hasSelection ? getChartColorError() : ALL_SPANS_COLOR}
                 isAnimationActive={false}
               >
                 {chartData.map((entry, index) => (
                   <Cell
                     key={`out-${index}`}
-                    fill={
-                      entry.isOther ? OTHER_BUCKET_COLOR : getChartColorError()
-                    }
-                  />
-                ))}
-              </Bar>
-              <Bar
-                dataKey="inlierCount"
-                name="Background"
-                fill={getChartColorSuccess()}
-                isAnimationActive={false}
-              >
-                {chartData.map((entry, index) => (
-                  <Cell
-                    key={`in-${index}`}
                     fill={
                       entry.isOther
                         ? OTHER_BUCKET_COLOR
-                        : getChartColorSuccess()
+                        : hasSelection
+                          ? getChartColorError()
+                          : ALL_SPANS_COLOR
                     }
                   />
                 ))}
               </Bar>
+              {hasSelection && (
+                <Bar
+                  dataKey="inlierCount"
+                  name="Background"
+                  fill={getChartColorSuccess()}
+                  isAnimationActive={false}
+                >
+                  {chartData.map((entry, index) => (
+                    <Cell
+                      key={`in-${index}`}
+                      fill={
+                        entry.isOther
+                          ? OTHER_BUCKET_COLOR
+                          : getChartColorSuccess()
+                      }
+                    />
+                  ))}
+                </Bar>
+              )}
             </BarChart>
           </ResponsiveContainer>
         </div>
@@ -262,14 +271,19 @@ export function PropertyComparisonChart({
               {clickedValue.length === 0 ? <i>Empty String</i> : clickedValue}
             </Text>
             <Flex gap={12} mb={8}>
-              <Text size="xs" c={getChartColorError()}>
-                Selection:{' '}
+              <Text
+                size="xs"
+                c={hasSelection ? getChartColorError() : ALL_SPANS_COLOR}
+              >
+                {hasSelection ? 'Selection' : 'All spans'}:{' '}
                 {(outlierValueOccurences.get(clickedValue) ?? 0).toFixed(1)}%
               </Text>
-              <Text size="xs" c={getChartColorSuccess()}>
-                Background:{' '}
-                {(inlierValueOccurences.get(clickedValue) ?? 0).toFixed(1)}%
-              </Text>
+              {hasSelection && (
+                <Text size="xs" c={getChartColorSuccess()}>
+                  Background:{' '}
+                  {(inlierValueOccurences.get(clickedValue) ?? 0).toFixed(1)}%
+                </Text>
+              )}
             </Flex>
             <Flex gap={4} align="center">
               {onAddFilter && (
diff --git a/packages/app/src/components/Search/DBSearchHeatmapChart.tsx b/packages/app/src/components/Search/DBSearchHeatmapChart.tsx
index 7fb8792846..8b3fedd186 100644
--- a/packages/app/src/components/Search/DBSearchHeatmapChart.tsx
+++ b/packages/app/src/components/Search/DBSearchHeatmapChart.tsx
@@ -14,8 +14,6 @@ import {
 } from '@hyperdx/common-utils/dist/types';
 import { Box, Flex } from '@mantine/core';
 import { Button } from '@mantine/core';
-import { Center } from '@mantine/core';
-import { Text } from '@mantine/core';
 import { IconPlayerPlay } from '@tabler/icons-react';
 
 import { SQLInlineEditorControlled } from '@/components/SQLEditor/SQLInlineEditor';
@@ -120,33 +118,19 @@ export function DBSearchHeatmapChart({
           }}
         />
       </div>
-      {fields.xMin != null &&
-      fields.xMax != null &&
-      fields.yMin != null &&
-      fields.yMax != null ? (
-        <DBDeltaChart
-          config={{
-            ...chartConfig,
-            with: undefined,
-          }}
-          valueExpr={fields.value}
-          xMin={fields.xMin}
-          xMax={fields.xMax}
-          yMin={fields.yMin}
-          yMax={fields.yMax}
-          onAddFilter={
-            onAddFilter ? handleAddFilterAndClearSelection : undefined
-          }
-          spanIdExpression={source.spanIdExpression}
-        />
-      ) : (
-        <Center mih={100} h="100%">
-          <Text size="sm">
-            Please highlight an outlier range in the heatmap to view the delta
-            chart.
-          </Text>
-        </Center>
-      )}
+      <DBDeltaChart
+        config={{
+          ...chartConfig,
+          with: undefined,
+        }}
+        valueExpr={fields.value}
+        xMin={fields.xMin}
+        xMax={fields.xMax}
+        yMin={fields.yMin}
+        yMax={fields.yMax}
+        onAddFilter={onAddFilter ? handleAddFilterAndClearSelection : undefined}
+        spanIdExpression={source.spanIdExpression}
+      />
     </Flex>
   );
 }
diff --git a/packages/app/src/components/deltaChartUtils.ts b/packages/app/src/components/deltaChartUtils.ts
index 21250cf021..d9c20f57f3 100644
--- a/packages/app/src/components/deltaChartUtils.ts
+++ b/packages/app/src/components/deltaChartUtils.ts
@@ -94,6 +94,9 @@ export const MAX_CHART_VALUES_UPPER = 8;
 // Color for the "Other (N)" aggregated bucket — neutral gray.
 export const OTHER_BUCKET_COLOR = 'var(--mantine-color-gray-5)';
 
+// Color for the "All spans" distribution bar (no selection / comparison mode off).
+export const ALL_SPANS_COLOR = 'var(--mantine-color-blue-6)';
+
 export function mergeValueStatisticsMaps(
   outlierValues: Map<string, number>, // value -> count
   inlierValues: Map<string, number>,