diff --git a/simple-index.html b/simple-index.html
index e74e1434..cd6140b6 100644
--- a/simple-index.html
+++ b/simple-index.html
@@ -60,7 +60,7 @@
               class="h-8 w-8"
             />
             <span class="text-white font-bold text-xl ml-2">
-              <a href="/"
+              <a href="{{baseUrl}}"
                 >{{#if brandName}}{{brandName}}{{else}}BentoPDF{{/if}}</a
               >
             </span>
diff --git a/src/js/logic/deskew-pdf-page.ts b/src/js/logic/deskew-pdf-page.ts
index 0428d704..f5467770 100644
--- a/src/js/logic/deskew-pdf-page.ts
+++ b/src/js/logic/deskew-pdf-page.ts
@@ -273,7 +273,7 @@ function initPage(): void {
 
   if (backBtn) {
     backBtn.addEventListener('click', () => {
-      window.location.href = '/';
+      window.location.href = import.meta.env.BASE_URL;
     });
   }
 
diff --git a/src/js/logic/form-filler-page.ts b/src/js/logic/form-filler-page.ts
index ae49b487..47772bdc 100644
--- a/src/js/logic/form-filler-page.ts
+++ b/src/js/logic/form-filler-page.ts
@@ -311,6 +311,6 @@ document.addEventListener('DOMContentLoaded', () => {
   processBtn?.addEventListener('click', processAndDownloadForm);
 
   backBtn?.addEventListener('click', () => {
-    window.location.href = '../../index.html';
+    window.location.href = import.meta.env.BASE_URL;
   });
 });
diff --git a/src/js/logic/markdown-to-pdf-page.ts b/src/js/logic/markdown-to-pdf-page.ts
index e104c983..3282f4cd 100644
--- a/src/js/logic/markdown-to-pdf-page.ts
+++ b/src/js/logic/markdown-to-pdf-page.ts
@@ -1,21 +1,21 @@
 import { MarkdownEditor } from '../utils/markdown-editor.js';
 
 document.addEventListener('DOMContentLoaded', () => {
-    const container = document.getElementById('markdown-editor-container');
+  const container = document.getElementById('markdown-editor-container');
 
-    if (!container) {
-        console.error('Markdown editor container not found');
-        return;
-    }
+  if (!container) {
+    console.error('Markdown editor container not found');
+    return;
+  }
 
-    const editor = new MarkdownEditor(container, {});
+  const editor = new MarkdownEditor(container, {});
 
-    console.log('Markdown editor initialized');
+  console.log('Markdown editor initialized');
 
-    const backButton = document.getElementById('back-to-tools');
-    if (backButton) {
-        backButton.addEventListener('click', () => {
-            window.location.href = '/';
-        });
-    }
+  const backButton = document.getElementById('back-to-tools');
+  if (backButton) {
+    backButton.addEventListener('click', () => {
+      window.location.href = import.meta.env.BASE_URL;
+    });
+  }
 });
diff --git a/src/js/logic/remove-annotations-page.ts b/src/js/logic/remove-annotations-page.ts
index 715f51a7..e190eebd 100644
--- a/src/js/logic/remove-annotations-page.ts
+++ b/src/js/logic/remove-annotations-page.ts
@@ -194,6 +194,6 @@ document.addEventListener('DOMContentLoaded', () => {
   processBtn?.addEventListener('click', processRemoveAnnotations);
 
   backBtn?.addEventListener('click', () => {
-    window.location.href = '../../index.html';
+    window.location.href = import.meta.env.BASE_URL;
   });
 });
diff --git a/src/js/logic/remove-blank-pages-page.ts b/src/js/logic/remove-blank-pages-page.ts
index 5b70b371..540e37c6 100644
--- a/src/js/logic/remove-blank-pages-page.ts
+++ b/src/js/logic/remove-blank-pages-page.ts
@@ -366,6 +366,6 @@ document.addEventListener('DOMContentLoaded', () => {
   processBtn?.addEventListener('click', processRemoveBlankPages);
 
   document.getElementById('back-to-tools')?.addEventListener('click', () => {
-    window.location.href = '../../index.html';
+    window.location.href = import.meta.env.BASE_URL;
   });
 });
diff --git a/src/tests/navigation-base-url.test.ts b/src/tests/navigation-base-url.test.ts
new file mode 100644
index 00000000..a5e7ecc5
--- /dev/null
+++ b/src/tests/navigation-base-url.test.ts
@@ -0,0 +1,101 @@
+import { describe, it, expect } from 'vitest';
+import * as fs from 'fs';
+import * as path from 'path';
+
+describe('Navigation BASE_URL Consistency', () => {
+  const logicDir = path.resolve(__dirname, '../js/logic');
+  const pagesDir = path.resolve(__dirname, '../pages');
+  const rootDir = path.resolve(__dirname, '../../');
+
+  it('ensures tool navigation assignments strictly use import.meta.env.BASE_URL', () => {
+    const files = fs
+      .readdirSync(logicDir)
+      .filter(
+        (file) =>
+          (file.endsWith('.ts') || file.endsWith('.js')) &&
+          file !== 'shortcuts.ts'
+      );
+
+    const nonCompliantAssignments: Array<{ file: string; target: string }> = [];
+
+    for (const file of files) {
+      const content = fs.readFileSync(path.join(logicDir, file), 'utf-8');
+      const assignments = content.matchAll(
+        /window\.location\.href\s*=\s*([^;\n]+)/g
+      );
+
+      for (const match of assignments) {
+        const target = match[1].trim();
+        if (!target.includes('import.meta.env.BASE_URL')) {
+          nonCompliantAssignments.push({ file, target });
+        }
+      }
+    }
+
+    expect(
+      nonCompliantAssignments,
+      `The following files assign window.location.href without import.meta.env.BASE_URL: ${JSON.stringify(
+        nonCompliantAssignments,
+        null,
+        2
+      )}`
+    ).toEqual([]);
+  });
+
+  it('ensures each affected back-button handler assigns import.meta.env.BASE_URL', () => {
+    const affectedFiles = [
+      'deskew-pdf-page.ts',
+      'markdown-to-pdf-page.ts',
+      'remove-annotations-page.ts',
+      'form-filler-page.ts',
+      'remove-blank-pages-page.ts',
+    ];
+
+    for (const file of affectedFiles) {
+      const content = fs.readFileSync(path.join(logicDir, file), 'utf-8');
+      expect(
+        content,
+        `${file} must assign window.location.href to import.meta.env.BASE_URL`
+      ).toMatch(/window\.location\.href\s*=\s*import\.meta\.env\.BASE_URL/);
+    }
+  });
+
+  it('ensures brand anchor in standalone templates asserts href="{{baseUrl}}"', () => {
+    const standaloneTemplates = [
+      path.join(rootDir, 'simple-index.html'),
+      path.join(rootDir, 'src/partials/navbar-simple.html'),
+    ];
+
+    for (const filePath of standaloneTemplates) {
+      if (!fs.existsSync(filePath)) continue;
+
+      const content = fs.readFileSync(filePath, 'utf-8');
+      const anchors = [
+        ...content.matchAll(
+          /<a\b[^>]*href=["']([^"']*)["'][^>]*>([\s\S]*?)<\/a\s*>/gi
+        ),
+      ];
+
+      const brandAnchor = anchors.find(([, , innerContent]) =>
+        /{{#if\s+brandName}}|BentoPDF/i.test(innerContent)
+      );
+
+      expect(
+        brandAnchor,
+        `Could not locate brand anchor in ${path.basename(filePath)}`
+      ).toBeDefined();
+
+      const href = brandAnchor?.[1];
+      expect(
+        href,
+        `Expected ${path.basename(filePath)} brand anchor href to be "{{baseUrl}}" but got "${href}"`
+      ).toBe('{{baseUrl}}');
+    }
+  });
+
+  it('ensures pdf-multi-tool uses standard navbar partial', () => {
+    const pdfMultiTool = path.join(pagesDir, 'pdf-multi-tool.html');
+    const content = fs.readFileSync(pdfMultiTool, 'utf-8');
+    expect(content).toContain('{{> navbar }}');
+  });
+});