diff --git a/src/plugins/network/RequestDetails.js b/src/plugins/network/RequestDetails.js
index f40dc6cc3..5c3278960 100644
--- a/src/plugins/network/RequestDetails.js
+++ b/src/plugins/network/RequestDetails.js
@@ -62,11 +62,15 @@ function decodeBody(container: Request | Response): string {
   if (!container.data) {
     return '';
   }
-  const b64Decoded = decodeURIComponent(escape(atob(container.data)));
+  const b64Decoded = atob(container.data);
+  const body =
+    getHeaderValue(container.headers, 'Content-Encoding') === 'gzip'
+      ? decompress(b64Decoded)
+      : b64Decoded;
 
-  return getHeaderValue(container.headers, 'Content-Encoding') === 'gzip'
-    ? decompress(b64Decoded)
-    : b64Decoded;
+  // Data is transferred as base64 encoded bytes to support unicode characters,
+  // we need to decode the bytes here to display the correct unicode characters.
+  return decodeURIComponent(escape(body));
 }
 
 function decompress(body: string): string {
diff --git a/src/plugins/network/index.js b/src/plugins/network/index.js
index bd90c2478..7a8413573 100644
--- a/src/plugins/network/index.js
+++ b/src/plugins/network/index.js
@@ -490,7 +490,10 @@ class SizeColumn extends PureComponent<{
     if (lengthString != null && lengthString != '') {
       length = parseInt(lengthString, 10);
     } else if (response.data) {
-      length = decodeURIComponent(escape(atob(response.data))).length;
+      // FIXME: T41427687 This is probably not the correct way to determine
+      // the correct byte size of the response, because String.length returns
+      // the number of characters, not bytes.
+      length = atob(response.data).length;
     }
     return length;
   }