# Parallel Chunk Upload with extension concatentation

**URL:** <https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412>\
**Category:** Tus\
**Created:** [January 1, 2025, 4:36am UTC](https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412 "2025-01-01T04:36:26Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tapas](https://yyz2.discourse-cdn.com/flex032/user_avatar/community.transloadit.com/tapas/32/1282_2.png) [@Tapas](https://community.transloadit.com/u/Tapas)\
**Post date:** [January 1, 2025, 4:36am UTC](https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412/1 "2025-01-01T04:36:26Z")

</div>

I am using tus-js-client for uploading file with parallelUploads: 5, and I have enabled concatentation extension in the tus-node-server, now all the chunks are uploaded successfully but when the last API is called it is failed with the status of 400.

 ![Screenshot 2024-12-23 at 11.38.33 AM](https://canada1.discourse-cdn.com/flex032/uploads/transloadit/original/2X/0/042e33b77d424e6b138fb4c2909e3d0db3c57116.png)

---

<div class="post-metadata">

**Author:** ![Merlijn](https://yyz2.discourse-cdn.com/flex032/user_avatar/community.transloadit.com/merlijn/32/1382_2.png) [@Merlijn](https://community.transloadit.com/u/Merlijn)\
**Post date:** [January 6, 2025, 8:41am UTC](https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412/2 "2025-01-06T08:41:18Z")

</div>

Hi, there is no concatenation extension in tus-node-server so you should disable `parallelUploads`.

---

<div class="post-metadata">

**Author:** ![Tapas](https://yyz2.discourse-cdn.com/flex032/user_avatar/community.transloadit.com/tapas/32/1282_2.png) [@Tapas](https://community.transloadit.com/u/Tapas)\
**Post date:** [January 6, 2025, 10:10am UTC](https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412/3 "2025-01-06T10:10:34Z")

</div>

Hello,

I got the info from [[Resumable upload protocol 1.0.x | tus.io](https://tus.io/protocols/resumable-upload#concatenation)]([https://Tus](https://Tus) Documentation).

---

<div class="post-metadata">

**Author:** ![Merlijn](https://yyz2.discourse-cdn.com/flex032/user_avatar/community.transloadit.com/merlijn/32/1382_2.png) [@Merlijn](https://community.transloadit.com/u/Merlijn)\
**Post date:** [January 6, 2025, 11:03am UTC](https://community.transloadit.com/t/parallel-chunk-upload-with-extension-concatentation/17412/4 "2025-01-06T11:03:55Z")

</div>

The spec describes it, that doesn’t mean every single server implements it.

See: [https://github.com/tus/tus-node-server?tab=readme-ov-file#extensions](https://github.com/tus/tus-node-server?tab=readme-ov-file#extensions)