diff --git a/.changeset/afraid-seals-rescue.md b/.changeset/afraid-seals-rescue.md
new file mode 100644
index 0000000..39e9f1c
--- /dev/null
+++ b/.changeset/afraid-seals-rescue.md
@@ -0,0 +1,5 @@
+---
+'@llamaindex/chat-ui': patch
+---
+
+fix: support releative URLs in document viewer
diff --git a/packages/chat-ui/src/widgets/document-info.tsx b/packages/chat-ui/src/widgets/document-info.tsx
index 2015793..f236afa 100644
--- a/packages/chat-ui/src/widgets/document-info.tsx
+++ b/packages/chat-ui/src/widgets/document-info.tsx
@@ -31,7 +31,8 @@ export function DocumentInfo({
   onRemove?: () => void
 }) {
   const { url, sources } = document
-  const fileName = urlToFileName(url)
+  const urlParts = url.split('/')
+  const fileName = urlParts.length > 0 ? urlParts[urlParts.length - 1] : url
   const fileExt = fileName?.split('.').pop() as DocumentFileType | undefined
 
   const previewFile = {
@@ -191,10 +192,3 @@ function DocumentPreviewCard(props: {
 function inKB(size: number) {
   return Math.round((size / 1024) * 10) / 10
 }
-
-function urlToFileName(url: string) {
-  const urlObj = new URL(url)
-  const urlParts = urlObj.pathname.split('/')
-  const fileName = urlParts.length > 0 ? urlParts[urlParts.length - 1] : url
-  return fileName
-}