# Why does GPT-5 ignore my prompts? **URL:** \ **Category:** API\ **Tags:** gpt-5\ **Created:** [October 7, 2025, 10:35pm UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451 "2025-10-07T22:35:34Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![tylersuard](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/tylersuard/32/448961_2.png) [@tylersuard](https://community.openai.com/u/tylersuard)\ **Post date:** [October 7, 2025, 10:35pm UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451/1 "2025-10-07T22:35:34Z")
Hello. I spent a few months working with o1 to write an advanced document transformation program. o1 handles all the prompting like a champ. However, when I put those exact same prompts into GPT-5 it fails miserably, even on high reasoning effort. What’s even worse, GPT-5 completely ignores my instructions. I am trying to modify my o1 prompt to work with GPT-5, but the changes that I make just get ignored. What is going on here, and how do I fix it? ---
**Author:** ![aprendendo.next](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/aprendendo.next/32/721758_2.png) [@aprendendo.next](https://community.openai.com/u/aprendendo.next)\ **Post date:** [October 7, 2025, 10:43pm UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451/2 "2025-10-07T22:43:16Z")
Welcome to the forum. Yes, gpt-5 prompting is a bit different from previous models. Have a look at these articles, they might help you a bit: - [GPT-5 prompting guide](https://cookbook.openai.com/examples/gpt-5/gpt-5_prompting_guide) - [GPT-5 Troubleshooting Guide](https://cookbook.openai.com/examples/gpt-5/gpt-5_troubleshooting_guide) ---
**Author:** ![PaulBellow](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/paulbellow/32/597962_2.png) [@PaulBellow](https://community.openai.com/u/PaulBellow)\ **Post date:** [October 7, 2025, 10:44pm UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451/3 "2025-10-07T22:44:18Z")
I’ve found the GPT-5 prompt optimizer helpful for a few things. [https://platform.openai.com/chat/edit?prompt=](https://platform.openai.com/chat/edit?prompt=) You will likely need to adapt the prompts, though. Were the old ones reasoning too? ---
**Author:** ![jeffvpace](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/jeffvpace/32/741732_2.png) [@jeffvpace](https://community.openai.com/u/jeffvpace)\ **Post date:** [October 7, 2025, 11:51pm UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451/4 "2025-10-07T23:51:32Z")
Depending on your prompt, the **verbosity** parameter (default **medium** ) may be problematic. For example, we translate entire documents and have to set verbosity to **low**. ---
**Author:** ![ninazane](https://avatars.discourse-cdn.com/v4/letter/n/5f9b8f/32.png) [@ninazane](https://community.openai.com/u/ninazane)\ **Post date:** [October 8, 2025, 10:28am UTC](https://community.openai.com/t/why-does-gpt-5-ignore-my-prompts/1361451/5 "2025-10-08T10:28:39Z")
Basically, your old **o1** prompt isn’t clicking with **GPT-5** because the two models think in different ways. - **o1** is great at reading between the lines — it reasons deeply and fills in gaps. - **GPT-5** is more literal — it wants clear, structured, no-nonsense instructions. So when you reuse your o1 prompt, GPT-5 either ignores parts of it or gets confused. Here’s how to fix it: 1. Put your must-follow rules in the **system message** , not the user prompt. 2. Use **structured outputs** (like JSON mode or function calling) instead of hoping it formats things right. 3. Set **temperature = 0** so it stays consistent. 4. Give it a **tiny example** of what you want. 5. Don’t rely on hidden “reasoning” — spell out the steps you expect. In short: make your prompt more **explicit, structured, and strict** , and GPT-5 will follow along just fine.