---
date: 2026-08-24T10:48:01+00:00
modified: 2026-08-24T10:48:01+00:00
permalink: https://kaspars.net/note/mastodon-social-117150795817671190
post_type: note
author:
  name: Kaspars
  avatar: https://reverse.kaspars.net/gravatar/avatar/92bfcd3a8c3a21a033a6484d32c25a40b113ec6891f674336081513d5c98ef76?s=96&d=mm&r=g
---

# On August 24, 2026 at 13:48

The OpenAI batch API is pretty cool at 50% of the cost. Great for large scale tasks such as captioning 42k images with gpt-5-mini.

Here is what I learned:

1\. there is an org-level cap of 5M enqueued tokens per model so you need to throttle the uploads to stay below that. Not sure why they don't take care of that internally;

2\. each batch upload must be below 200MB of so I had to create 75 JSONL files (multiple JSON objects per line) for 42k images resized to 1536px on the long edge.