diff --git a/src/core/xfa/template.js b/src/core/xfa/template.js
index 8ec158ff888fe..454ceb5f0fca2 100644
--- a/src/core/xfa/template.js
+++ b/src/core/xfa/template.js
@@ -102,7 +102,7 @@ import {
   getStringOption,
   HTMLResult,
 } from "./utils.js";
-import { stringToBytes, Util, warn } from "../../shared/util.js";
+import { Util, warn } from "../../shared/util.js";
 import { getMetrics } from "./fonts.js";
 import { recoverJsURL } from "../core_utils.js";
 import { searchNode } from "./som.js";
@@ -3427,7 +3427,7 @@ class Image extends StringObject {
     }
 
     if (!buffer && this.transferEncoding === "base64") {
-      buffer = stringToBytes(atob(this[$content]));
+      buffer = Uint8Array.fromBase64(this[$content]);
     }
 
     if (!buffer) {
diff --git a/src/display/font_loader.js b/src/display/font_loader.js
index 1014c536b67e0..4115a71eb5d79 100644
--- a/src/display/font_loader.js
+++ b/src/display/font_loader.js
@@ -15,7 +15,6 @@
 
 import {
   assert,
-  bytesToString,
   FontRenderOps,
   isNodeJS,
   shadow,
@@ -399,9 +398,8 @@ class FontFaceObject {
     if (!this.data || this.disableFontFace) {
       return null;
     }
-    const data = bytesToString(this.data);
     // Add the @font-face rule to the document.
-    const url = `url(data:${this.mimetype};base64,${btoa(data)});`;
+    const url = `url(data:${this.mimetype};base64,${this.data.toBase64()});`;
     let rule;
     if (!this.cssFontInfo) {
       rule = `@font-face {font-family:"${this.loadedName}";src:${url}}`;