diff --git a/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
index a43fe5b940..f5a1d92df4 100644
--- a/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
@@ -250,11 +250,49 @@ static ErrorOr<Extensions> read_extensions(LittleEndianInputBitStream& stream)
 ///
 
 /// K.2 - Non-separable upsampling
-Array<double, 15> s_d_up2 {
+Array s_d_up2 {
     -0.01716200, -0.03452303, -0.04022174, -0.02921014, -0.00624645,
     0.14111091, 0.28896755, 0.00278718, -0.01610267, 0.56661550,
     0.03777607, -0.01986694, -0.03144731, -0.01185068, -0.00213539
 };
+
+Array s_d_up4 = {
+    -0.02419067, -0.03491987, -0.03693351, -0.03094285, -0.00529785,
+    -0.01663432, -0.03556863, -0.03888905, -0.03516850, -0.00989469,
+    0.23651958, 0.33392945, -0.01073543, -0.01313181, -0.03556694,
+    0.13048175, 0.40103025, 0.03951150, -0.02077584, 0.46914198,
+    -0.00209270, -0.01484589, -0.04064806, 0.18942530, 0.56279892,
+    0.06674400, -0.02335494, -0.03551682, -0.00754830, -0.02267919,
+    -0.02363578, 0.00315804, -0.03399098, -0.01359519, -0.00091653,
+    -0.00335467, -0.01163294, -0.01610294, -0.00974088, -0.00191622,
+    -0.01095446, -0.03198464, -0.04455121, -0.02799790, -0.00645912,
+    0.06390599, 0.22963888, 0.00630981, -0.01897349, 0.67537268,
+    0.08483369, -0.02534994, -0.02205197, -0.01667999, -0.00384443
+};
+
+Array s_d_up8 {
+    -0.02928613, -0.03706353, -0.03783812, -0.03324558, -0.00447632, -0.02519406, -0.03752601, -0.03901508, -0.03663285, -0.00646649,
+    -0.02066407, -0.03838633, -0.04002101, -0.03900035, -0.00901973, -0.01626393, -0.03954148, -0.04046620, -0.03979621, -0.01224485,
+    0.29895328, 0.35757708, -0.02447552, -0.01081748, -0.04314594, 0.23903219, 0.41119301, -0.00573046, -0.01450239, -0.04246845,
+    0.17567618, 0.45220643, 0.02287757, -0.01936783, -0.03583255, 0.11572472, 0.47416733, 0.06284440, -0.02685066, 0.42720050,
+    -0.02248939, -0.01155273, -0.04562755, 0.28689496, 0.49093869, -0.00007891, -0.01545926, -0.04562659, 0.21238920, 0.53980934,
+    0.03369474, -0.02070211, -0.03866988, 0.14229550, 0.56593398, 0.08045181, -0.02888298, -0.03680918, -0.00542229, -0.02920477,
+    -0.02788574, -0.02118180, -0.03942402, -0.00775547, -0.02433614, -0.03193943, -0.02030828, -0.04044014, -0.01074016, -0.01930822,
+    -0.03620399, -0.01974125, -0.03919545, -0.01456093, -0.00045072, -0.00360110, -0.01020207, -0.01231907, -0.00638988, -0.00071592,
+    -0.00279122, -0.00957115, -0.01288327, -0.00730937, -0.00107783, -0.00210156, -0.00890705, -0.01317668, -0.00813895, -0.00153491,
+    -0.02128481, -0.04173044, -0.04831487, -0.03293190, -0.00525260, -0.01720322, -0.04052736, -0.05045706, -0.03607317, -0.00738030,
+    -0.01341764, -0.03965629, -0.05151616, -0.03814886, -0.01005819, 0.18968273, 0.33063684, -0.01300105, -0.01372950, -0.04017465,
+    0.13727832, 0.36402234, 0.01027890, -0.01832107, -0.03365072, 0.08734506, 0.38194295, 0.04338228, -0.02525993, 0.56408126,
+    0.00458352, -0.01648227, -0.04887868, 0.24585519, 0.62026135, 0.04314807, -0.02213737, -0.04158014, 0.16637289, 0.65027023,
+    0.09621636, -0.03101388, -0.04082742, -0.00904519, -0.02790922, -0.02117818, 0.00798662, -0.03995711, -0.01243427, -0.02231705,
+    -0.02946266, 0.00992055, -0.03600283, -0.01684920, -0.00111684, -0.00411204, -0.01297130, -0.01723725, -0.01022545, -0.00165306,
+    -0.00313110, -0.01218016, -0.01763266, -0.01125620, -0.00231663, -0.01374149, -0.03797620, -0.05142937, -0.03117307, -0.00581914,
+    -0.01064003, -0.03608089, -0.05272168, -0.03375670, -0.00795586, 0.09628104, 0.27129991, -0.00353779, -0.01734151, -0.03153981,
+    0.05686230, 0.28500998, 0.02230594, -0.02374955, 0.68214326, 0.05018048, -0.02320852, -0.04383616, 0.18459474, 0.71517975,
+    0.10805613, -0.03263677, -0.03637639, -0.01394373, -0.02511203, -0.01728636, 0.05407331, -0.02867568, -0.01893131, -0.00240854,
+    -0.00446511, -0.01636187, -0.02377053, -0.01522848, -0.00333334, -0.00819975, -0.02964169, -0.04499287, -0.02745350, -0.00612408,
+    0.02727416, 0.19446600, 0.00159832, -0.02232473, 0.74982506, 0.11452620, -0.03348048, -0.01605681, -0.02070339, -0.00458223
+};
 ///
 
 /// D.3 - Image metadata
@@ -307,7 +345,8 @@ struct ImageMetadata {
     u8 cw_mask { 0 };
 
     Array<double, 15> up2_weight = s_d_up2;
-    // TODO: add up[4, 8]_weight
+    Array<double, 55> up4_weight = s_d_up4;
+    Array<double, 210> up8_weight = s_d_up8;
 };
 
 static ErrorOr<ImageMetadata> read_metadata_header(LittleEndianInputBitStream& stream)
@@ -1529,11 +1568,19 @@ static ErrorOr<void> apply_upsampling(Image& image, ImageMetadata const& metadat
     }
 
     if (frame.frame_header.upsampling > 1 || ec_max.value_or(0) > 1) {
-        if (frame.frame_header.upsampling > 2 || ec_max.value_or(0) > 2)
+        if (ec_max.value_or(0) > 2)
             TODO();
 
         auto const k = frame.frame_header.upsampling;
 
+        auto weight = [k, &metadata](u8 index) -> double {
+            if (k == 2)
+                return metadata.up2_weight[index];
+            if (k == 4)
+                return metadata.up4_weight[index];
+            return metadata.up8_weight[index];
+        };
+
         // FIXME: Use ec_upsampling for extra-channels
         for (auto& channel : image.channels()) {
             auto upsampled = TRY(Channel::create(k * channel.width(), k * channel.height()));
@@ -1565,7 +1612,7 @@ static ErrorOr<void> apply_upsampling(Image& image, ImageMetadata const& metadat
                                     W_min = min(W_min, origin_sample);
                                     W_max = max(W_max, origin_sample);
 
-                                    sum += origin_sample * metadata.up2_weight[index];
+                                    sum += origin_sample * weight(index);
                                 }
                             }