---
title: "Does OpenAI prompt caching work when only part of my prompt stays the same?"  
description: "Does OpenAI prompt caching work when only part of my prompt stays the same?"  
author: "Katherine Sullivan"  
published: 2026-10-22  
updated: 2026-10-22  
canonical: https://www.mindstick.com/forum/162746/does-openai-prompt-caching-work-when-only-part-of-my-prompt-stays-the-same  
category: "OpenAI API"  
tags: ["OpenAI", "API Development", "Prompt Caching"]  
reading_time: 1 minute  

---

# Does OpenAI prompt caching work when only part of my prompt stays the same?

I’m trying to reduce repeated input costs in an OpenAI API workflow where the instructions and reference material stay mostly fixed, but each request adds different user details. Does **[OpenAI prompt caching](https://www.mindstick.com/forum/162363/is-openai-prompt-caching-worth-reorganizing-a-frequently-used-prompt)** still help if the changing content appears near the beginning of the prompt, or does that prevent the later shared text from being reused?

I’d be interested in how people structure prompts for this and which usage or response fields they check to confirm that a cache hit actually happened.


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Original Source: https://www.mindstick.com/forum/162746/does-openai-prompt-caching-work-when-only-part-of-my-prompt-stays-the-same

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