diff --git a/src/methods/generateImageInfoUrl.test.ts b/src/methods/generateImageInfoUrl.test.ts
index 00a9007..add0de1 100644
--- a/src/methods/generateImageInfoUrl.test.ts
+++ b/src/methods/generateImageInfoUrl.test.ts
@@ -2,7 +2,7 @@ import { describe, expect, it } from "vitest";
 import { OptionsImageInfo } from "@imgproxy/imgproxy-js-core";
 import generateImageInfoUrl from "./generateImageInfoUrl";
 
-describe("generateImageInfourl", () => {
+describe("generateImageInfoUrl", () => {
   it("should generate a valid URL", () => {
     const options: OptionsImageInfo = {
       average: { average: 1, ignore_transparent: "f" },
@@ -43,7 +43,7 @@ describe("generateImageInfourl", () => {
     });
 
     expect(result).toBe(
-      "https://imgproxy.example.com/info/insecure/bh:4:3/d:f/f:t/xmp:f/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc="
+      "https://imgproxy.example.com/info/insecure/bh:4:3/d:f/f:t/xmp:f/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc"
     );
   });
 
@@ -56,7 +56,7 @@ describe("generateImageInfourl", () => {
     });
 
     expect(result).toBe(
-      "https://imgproxy.example.com/info/S27LCUL9UqVzUUEh4PuP2fMuoszQetA6qj5T07tlmZ4/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc="
+      "https://imgproxy.example.com/info/xOner18d7-LJwkl4bifXGbC1_4kZXxsPLnuuvsMtcWo/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc"
     );
   });
 
diff --git a/src/methods/generateImageUrl.test.ts b/src/methods/generateImageUrl.test.ts
index e30a5c0..2ec77df 100644
--- a/src/methods/generateImageUrl.test.ts
+++ b/src/methods/generateImageUrl.test.ts
@@ -22,7 +22,7 @@ describe("generateImageUrl", () => {
     });
 
     expect(result).toBe(
-      "https://imgproxy.example.com/OISSn9zHS-E-xpsQPcsvKaTLVJePQgHG3MvDBbvk5lU/el:t/f:png/g:no/h:300/rt:fit/w:300/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc="
+      "https://imgproxy.example.com/zsdsCjFCqcAniKFCygMBToRh6l5jVZbL0bhrnnUGK58/el:t/f:png/g:no/h:300/rt:fit/w:300/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc"
     );
   });
 
@@ -44,7 +44,7 @@ describe("generateImageUrl", () => {
     });
 
     expect(result).toBe(
-      "https://imgproxy.example.com/insecure/ar:t/cb:clear/ex:t/f:webp/g:noea:10:10/sa:10/w:300/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc="
+      "https://imgproxy.example.com/insecure/ar:t/cb:clear/ex:t/f:webp/g:noea:10:10/sa:10/w:300/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc"
     );
   });
 
@@ -57,7 +57,7 @@ describe("generateImageUrl", () => {
     });
 
     expect(result).toBe(
-      "https://imgproxy.example.com/S27LCUL9UqVzUUEh4PuP2fMuoszQetA6qj5T07tlmZ4/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc="
+      "https://imgproxy.example.com/xOner18d7-LJwkl4bifXGbC1_4kZXxsPLnuuvsMtcWo/aHR0cHM6Ly9leGFtcGxlLmNvbS9pbWFnZS5qcGc"
     );
   });
 
diff --git a/src/utils/bufferToBase64.test.ts b/src/utils/bufferToBase64.test.ts
new file mode 100644
index 0000000..e8fbe24
--- /dev/null
+++ b/src/utils/bufferToBase64.test.ts
@@ -0,0 +1,28 @@
+import { describe, expect, it } from "vitest";
+import bufferToBase64 from "./bufferToBase64";
+
+describe("bufferToBase64", () => {
+  it("should return a base64 string", () => {
+    const result = bufferToBase64(Buffer.from("Hello, World!"));
+
+    expect(result).toBe("SGVsbG8sIFdvcmxkIQ");
+  });
+
+  it("should return a base64 string without padding", () => {
+    const result = bufferToBase64(Buffer.from("Hello, World!"));
+
+    expect(result).not.toContain("=");
+  });
+
+  it("should return a base64 string with - instead of +", () => {
+    const result = bufferToBase64(Buffer.from("Hello World!"));
+
+    expect(result).not.toContain("+");
+  });
+
+  it("should return a base64 string with _ instead of /", () => {
+    const result = bufferToBase64(Buffer.from("attached/attachment.jpg"));
+
+    expect(result).not.toContain("/");
+  });
+});
diff --git a/src/utils/bufferToBase64.ts b/src/utils/bufferToBase64.ts
new file mode 100644
index 0000000..fc031e6
--- /dev/null
+++ b/src/utils/bufferToBase64.ts
@@ -0,0 +1,9 @@
+const bufferToBase64 = (buffer: Buffer): string => {
+  return buffer
+    .toString("base64")
+    .replace(/=/g, "")
+    .replace(/\+/g, "-")
+    .replace(/\//g, "_");
+};
+
+export default bufferToBase64;
diff --git a/src/utils/getEncryptedUrl.ts b/src/utils/getEncryptedUrl.ts
index ac367d1..aec4d14 100644
--- a/src/utils/getEncryptedUrl.ts
+++ b/src/utils/getEncryptedUrl.ts
@@ -1,5 +1,6 @@
 import crypto from "crypto";
 import { ICryptPair } from "../types.js";
+import bufferToBase64 from "./bufferToBase64.js";
 import withCache from "./withCache.js";
 
 const getEncryptedUrl = (url: string, pair: ICryptPair): string => {
@@ -13,11 +14,7 @@ const getEncryptedUrl = (url: string, pair: ICryptPair): string => {
     "binary"
   );
 
-  return Buffer.concat([iv, encrypted])
-    .toString("base64")
-    .replace(/=/g, "")
-    .replace(/\+/g, "-")
-    .replace(/\//g, "_");
+  return bufferToBase64(Buffer.concat([iv, encrypted]));
 };
 
 const withCacheGetEncryptedUrl = withCache(getEncryptedUrl);
diff --git a/src/utils/normalizeUrl.ts b/src/utils/normalizeUrl.ts
index 31b6e89..0a1bb12 100644
--- a/src/utils/normalizeUrl.ts
+++ b/src/utils/normalizeUrl.ts
@@ -1,5 +1,6 @@
 import type { URL } from "@imgproxy/imgproxy-js-core";
 import type { IRawUrl } from "../types";
+import bufferToBase64 from "./bufferToBase64.js";
 import getEncryptPair from "./getEncryptPair.js";
 import getEncryptedUrl from "./getEncryptedUrl.js";
 
@@ -17,7 +18,7 @@ const normalizeUrl = ({ url, encryptKey, encryptIV }: INormalizeUrl): URL => {
 
   //encoded url to base64
   if (changedUrl.type === "base64") {
-    changedUrl.value = btoa(changedUrl.value);
+    changedUrl.value = bufferToBase64(Buffer.from(changedUrl.value));
   }
 
   //encrypting url