diff --git a/src/core/backend_fit.cpp b/src/core/backend_fit.cpp
index 0ba2df14f..18ea5c572 100644
--- a/src/core/backend_fit.cpp
+++ b/src/core/backend_fit.cpp
@@ -370,6 +370,13 @@ namespace sd::backend_fit {
             retry_mode                    = tiling_params.enabled ? "spatial+temporal" : "temporal";
         } else if (!tiling_params.enabled) {
             tiling_params.enabled = true;
+            // 512px VAE decode memory fix: get_tile_sizes() defaults to
+            // rel_size=1.0 (factor branch wins), which yields a full-size tile
+            // (tiling effectively disabled) and can exceed device buffer limits
+            // (Adreno 740: 512px decode graph ~1.94GB). Half-relative tiles make
+            // tiling effective (~416MB), no quality impact (VAE tiling overlaps).
+            tiling_params.rel_size_x = 0.5f;
+            tiling_params.rel_size_y = 0.5f;
             if (tiling_params.tile_size_x <= 0) {
                 tiling_params.tile_size_x = 256;
             }
diff --git a/src/stable-diffusion.cpp b/src/stable-diffusion.cpp
index d2193e14c..57887650a 100644
--- a/src/stable-diffusion.cpp
+++ b/src/stable-diffusion.cpp
@@ -3085,8 +3085,11 @@ class StableDiffusionGGML {
         auto latents                      = first_stage_model->diffusion_to_vae_latents(x);
         auto decoded                      = first_stage_model->decode(n_threads, latents, vae_tiling_params, decode_video, circular_x, circular_y);
         const bool prefer_temporal_tiling = decode_video && first_stage_model->can_temporal_tile_decode();
+        // 512px VAE decode memory fix: retry with tiling unconditionally on
+        // decode failure (OOM) instead of gating on --auto-fit (default off),
+        // so mobile GPUs with small buffers recover automatically. Only fires
+        // when decode actually failed, no side effects on the happy path.
         while (decoded.empty() &&
-               auto_fit_enabled &&
                sd::backend_fit::prepare_vae_decode_retry_tiling(vae_tiling_params, prefer_temporal_tiling)) {
             first_stage_model->free_compute_buffer();
             decoded = first_stage_model->decode(n_threads, latents, vae_tiling_params, decode_video, circular_x, circular_y);