---
title: "Add upload part"
method: POST
path: "/uploads/{upload_id}/parts"
tags: ["Uploads"]
---

# Add upload part

`POST /uploads/{upload_id}/parts`

Adds a [Part](https://developers.openai.com/api/reference/resources/uploads/subresources/parts) to an [Upload](https://developers.openai.com/api/reference/resources/uploads) object. A Part represents a chunk of bytes from the file you are trying to upload.

Each Part can be at most 64 MB, and you can add Parts until you hit the Upload maximum of 8 GB.

It is possible to add multiple Parts in parallel. You can decide the intended order of the Parts when you [complete the Upload](https://developers.openai.com/api/reference/resources/uploads/methods/complete).

## Path parameters

- `upload_id` string, required

## Response `200`

OK

- UploadPart — The upload Part represents a chunk of bytes we can add to an Upload object.
  - `id` string, required — The upload Part unique identifier, which can be referenced in API endpoints.
  - `created_at` integer, required — The Unix timestamp (in seconds) for when the Part was created.
  - `upload_id` string, required — The ID of the Upload object that this Part was added to.
  - `object` 'upload.part', required — The object type, which is always `upload.part`.

## Other responses

- `400` — The upload cannot accept more parts, or the part exceeds an upload size limit.
- `404` — The upload was not found.
- `410` — The upload has expired. Create a new upload before adding parts or completing it.
- `429` — Too many upload requests. Reduce the request rate and try again later.
- `500` — The part could not be uploaded. Try the request again.

## Changes

- **2026-09-25** `cda988e2e364` — 5 info
  - added the non-success response with the status `400`
  - added the non-success response with the status `404`
  - added the non-success response with the status `410`
  - added the non-success response with the status `429`
  - …1 more
- **2024-07-18** `bddc980d3fbb` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/openai/apis/openapi/changes/uploads/:upload_id/parts/post.md)

---

[API](https://skmtc.dev/openai/apis/openapi.md) · [All operations](https://skmtc.dev/openai/apis/openapi/llms.txt) · [OpenAPI document](https://skmtc.dev/openai/apis/openapi/revisions/4b75527da17b?raw)