diff --git a/TUS-Resumable-Uploads.md b/TUS-Resumable-Uploads.md
index c709e55..18d1c6a 100644
--- a/TUS-Resumable-Uploads.md
+++ b/TUS-Resumable-Uploads.md
@@ -6,6 +6,7 @@ SeaweedFS supports the [TUS](https://tus.io) protocol for resumable file uploads
 
 - **Resumable uploads**: Resume interrupted uploads without re-sending data
 - **Chunked uploads**: Upload large files in smaller pieces
+- **Parallel uploads**: Upload parts of a file concurrently and concatenate them server-side
 - **Simple protocol**: Standard HTTP methods with custom headers
 - **Wide client support**: Libraries available for JavaScript, Python, Go, Java, and more
 
@@ -68,6 +69,7 @@ weed server -filer=true -filer.tusBasePath=
 - `creation`: Create new upload sessions
 - `creation-with-upload`: Upload data in the creation request
 - `termination`: Cancel/delete uploads
+- `concatenation`: Concatenate completed partial uploads into one file, enabling parallel uploads
 
 ## Usage Examples
 
@@ -82,7 +84,7 @@ Response headers:
 ```
 Tus-Resumable: 1.0.0
 Tus-Version: 1.0.0
-Tus-Extension: creation,creation-with-upload,termination
+Tus-Extension: creation,creation-with-upload,termination,concatenation
 Tus-Max-Size: 5368709120
 ```
 
@@ -153,6 +155,51 @@ curl -X DELETE http://localhost:8888/.tus/.uploads/abc123-uuid \
   -H "Tus-Resumable: 1.0.0"
 ```
 
+### 7. Parallel Upload with Concatenation
+
+Upload parts of one file concurrently as partial uploads, then concatenate them in order:
+
+```bash
+# Create a partial upload per part (Upload-Length is that part's size)
+curl -i -X POST http://localhost:8888/.tus/path/to/file.txt \
+  -H "Tus-Resumable: 1.0.0" \
+  -H "Upload-Concat: partial" \
+  -H "Upload-Length: 500"
+# Location: /.tus/.uploads/part1-uuid
+
+curl -i -X POST http://localhost:8888/.tus/path/to/file.txt \
+  -H "Tus-Resumable: 1.0.0" \
+  -H "Upload-Concat: partial" \
+  -H "Upload-Length: 500"
+# Location: /.tus/.uploads/part2-uuid
+
+# Upload the parts, concurrently if desired
+curl -X PATCH http://localhost:8888/.tus/.uploads/part1-uuid \
+  -H "Tus-Resumable: 1.0.0" \
+  -H "Upload-Offset: 0" \
+  -H "Content-Type: application/offset+octet-stream" \
+  --data-binary @part1.bin &
+curl -X PATCH http://localhost:8888/.tus/.uploads/part2-uuid \
+  -H "Tus-Resumable: 1.0.0" \
+  -H "Upload-Offset: 0" \
+  -H "Content-Type: application/offset+octet-stream" \
+  --data-binary @part2.bin &
+wait
+
+# Concatenate the completed partials, in order, into the final file
+curl -X POST http://localhost:8888/.tus/path/to/file.txt \
+  -H "Tus-Resumable: 1.0.0" \
+  -H "Upload-Concat: final;/.tus/.uploads/part1-uuid /.tus/.uploads/part2-uuid"
+```
+
+Notes:
+
+- A completed partial does not appear at the target path; the file is created by the final request.
+- The final request must not include `Upload-Length`; the file size is the sum of the partial sizes, capped by `-tusMaxSizeMB`.
+- All listed partials must be finished before concatenation; concatenating an unfinished partial fails.
+- Concatenation consumes the partials, so each partial can be used only once.
+- Partials that are never concatenated expire like any other session after `-tusSessionExpiry`.
+
 ## TUS Headers
 
 ### Request Headers
@@ -163,6 +210,7 @@ curl -X DELETE http://localhost:8888/.tus/.uploads/abc123-uuid \
 | `Upload-Length` | POST | Total file size in bytes |
 | `Upload-Offset` | PATCH | Current byte offset |
 | `Upload-Metadata` | Optional | Base64-encoded key-value pairs |
+| `Upload-Concat` | Optional | `partial` creates a partial upload; `final;<url1> <url2> ...` concatenates completed partials |
 | `Content-Type` | PATCH | Must be `application/offset+octet-stream` |
 | `Content-Length` | PATCH | Size of data being uploaded |
 
@@ -201,6 +249,8 @@ const file = document.querySelector("input[type=file]").files[0];
 const upload = new tus.Upload(file, {
   endpoint: "http://localhost:8888/.tus/uploads/",
   retryDelays: [0, 3000, 5000, 10000, 20000],
+  parallelUploads: 3, // uses the concatenation extension
+
   metadata: {
     filename: file.name,
     filetype: file.type,
@@ -267,9 +317,10 @@ func main() {
 
 ## Limitations
 
-- Maximum upload size: 5GB by default, configurable with `-tusMaxSizeMB`
+- Maximum upload size: 5GB by default, configurable with `-tusMaxSizeMB`; a concatenated file's total size is capped by the same limit
 - Session expiration: 24 hours by default, configurable with `-tusSessionExpiry`; expired sessions are removed by an hourly background cleanup
-- Only single-file uploads (no concatenation extension)
+- Concatenation partials are single-use: once concatenated into a final upload they are consumed and cannot be reused
+- `concatenation-unfinished` is not supported: all partials must be complete before the final request
 
 ## See Also