diff --git a/frontend/src/app/render_wasm/api.cljs b/frontend/src/app/render_wasm/api.cljs
index f0bd78b351..f63ab88abd 100644
--- a/frontend/src/app/render_wasm/api.cljs
+++ b/frontend/src/app/render_wasm/api.cljs
@@ -64,6 +64,15 @@
 
 (def use-dpr? (contains? cf/flags :render-wasm-dpr))
 
+(defn- wasm-get-numeric-value
+  "Read a positive numeric query param (e.g. `?dpr=2`)."
+  [name]
+  (when-let [raw (let [p (rt/get-params @st/state)]
+                   (get p name))]
+    (let [n (if (string? raw) (js/parseFloat raw) raw)]
+      (when (and (number? n) (not (js/isNaN n)) (pos? n))
+        n))))
+
 ;; --- Page transition state (WASM viewport)
 ;;
 ;; Goal: avoid showing tile-by-tile rendering during page switches (and initial load),
@@ -296,14 +305,18 @@
 
 (defn get-dpr
   "Returns the current device pixel ratio. Use instead of `dpr` wherever
-   the value must reflect browser-zoom changes that happen after load."
+   the value must reflect browser-zoom changes that happen after load.
+
+   Override with query param `?dpr=2` (or any positive number) for HiDPI repro
+   without relying on the real `devicePixelRatio`."
   []
-  (if use-dpr?
-    (let [d (.-devicePixelRatio ^js ug/window)]
-      ;; In workers `ug/window` is a mock without `devicePixelRatio`,
-      ;; so guard against nil/NaN/non-positive values.
-      (if (and (number? d) (pos? d)) d 1.0))
-    1.0))
+  (or (wasm-get-numeric-value :dpr)
+      (if use-dpr?
+        (let [d (.-devicePixelRatio ^js ug/window)]
+          ;; In workers `ug/window` is a mock without `devicePixelRatio`,
+          ;; so guard against nil/NaN/non-positive values.
+          (if (and (number? d) (pos? d)) d 1.0))
+        1.0)))
 
 (def noop-fn
   (constantly nil))
@@ -2165,14 +2178,6 @@
       (set-render-options! dpr)
       (resize-viewbox (/ new-physical-w dpr) (/ new-physical-h dpr)))))
 
-(defn- wasm-get-numeric-value
-  [name]
-  (when-let [raw (let [p (rt/get-params @st/state)]
-                   (get p name))]
-    (let [n (if (string? raw) (js/parseFloat raw) raw)]
-      (when (and (number? n) (not (js/isNaN n)) (pos? n))
-        n))))
-
 (defn- wasm-set-param-from-route-params-if-present
   [param-name]
   (when-let [value (wasm-get-numeric-value param-name)]