diff --git a/src/docgen/generators/html.py b/src/docgen/generators/html.py
new file mode 100644
index 0000000..7728eb5
--- /dev/null
+++ b/src/docgen/generators/html.py
@@ -0,0 +1,75 @@
+"""HTML documentation generator."""
+
+import re
+from pathlib import Path
+from jinja2 import Environment, FileSystemLoader, select_autoescape
+from docgen.models import DocConfig, Endpoint
+from docgen.generators import BaseGenerator
+
+
+def slugify(text: str) -> str:
+    """Convert text to URL-friendly slug."""
+    return re.sub(r'[^a-z0-9]+', '-', text.lower()).strip('-')
+
+
+class HTMLGenerator(BaseGenerator):
+    """Generator for Stripe-like interactive HTML documentation."""
+
+    def __init__(self, config: DocConfig = None):
+        super().__init__(config)
+        template_dir = Path(__file__).parent.parent / "templates"
+        self.env = Environment(
+            loader=FileSystemLoader(template_dir),
+            autoescape=select_autoescape(["html", "xml"]),
+        )
+        self.env.filters["slugify"] = slugify
+
+    def generate(self, endpoints: list[Endpoint], output_dir: Path) -> Path:
+        """Generate HTML documentation."""
+        output_dir = self._ensure_output_dir(output_dir)
+
+        grouped = self._group_endpoints(endpoints)
+        base_template = self.env.get_template("base.html.jinja2")
+        sidebar_template = self.env.get_template("sidebar.html.jinja2")
+
+        rendered_content = base_template.render(
+            title=self.config.title,
+            description=self.config.description,
+            version=self.config.version,
+            endpoints=endpoints,
+            grouped_endpoints=grouped,
+            sidebar=sidebar_template.render(grouped_endpoints=grouped),
+            theme=self.config.theme,
+        )
+
+        index_path = output_dir / "index.html"
+        index_path.write_text(rendered_content)
+
+        self._copy_static_files(output_dir)
+
+        return index_path
+
+    def _group_endpoints(self, endpoints: list[Endpoint]) -> dict[str, list[Endpoint]]:
+        """Group endpoints by tags or path prefixes."""
+        grouped = {}
+        for endpoint in endpoints:
+            if endpoint.tags:
+                tag = endpoint.tags[0] if endpoint.tags else "Other"
+            else:
+                parts = endpoint.path.strip("/").split("/")
+                tag = parts[0] if parts else "Other"
+            
+            if tag not in grouped:
+                grouped[tag] = []
+            grouped[tag].append(endpoint)
+        return dict(sorted(grouped.items()))
+
+    def _copy_static_files(self, output_dir: Path) -> None:
+        """Copy static CSS and JS files to output directory."""
+        static_dir = Path(__file__).parent.parent / "static"
+        output_static = output_dir / "static"
+        output_static.mkdir(exist_ok=True)
+        
+        for file in static_dir.iterdir():
+            if file.is_file():
+                (output_static / file.name).write_text(file.read_text())