FixMyPrompt vs ChatGPT Custom Instructions
Built into ChatGPT set persistent prompt context.
- Home
/ FixMyPrompt vs ChatGPT Custom Instructions
Who is ChatGPT Custom Instructions?
Custom Instructions is a free ChatGPT feature where you set two text boxes 'about you' and 'how you want responses formatted' that apply to every chat. They give baseline context. They do not fix the specific prompt you're about to send.
Side-by-side comparison
| Axis | FixMyPrompt | ChatGPT Custom Instructions | Winner |
|---|---|---|---|
| Per-prompt fixing | Yes analyzes the exact prompt | No applies the same context to every chat | FixMyPrompt |
| Persistent identity context | No stateless QA | Yes set once, applies to all chats | Them |
| Scored rubric | Yes 0–100 with weak-spot diagnosis | No | FixMyPrompt |
| Works with Claude/Gemini/Midjourney | Yes model-agnostic | ChatGPT only | FixMyPrompt |
| Image prompts | Yes dedicated rubric | No | FixMyPrompt |
| Cost | Free 3/day, pay-as-you-go from $2.99 | Free with ChatGPT account | Them |
When ChatGPT Custom Instructions wins
- You want the same context applied to every ChatGPT chat (job title, response style).
- You only use ChatGPT and don't need cross-model help.
When FixMyPrompt wins
- A specific prompt is failing and you need to know why.
- You use Claude, Gemini, or Midjourney alongside ChatGPT.
- You want to learn the rubric so you can write better prompts without a tool.
Bottom line
Use Custom Instructions to set who-you-are defaults once. Use FixMyPrompt when a specific prompt isn't producing the output you want. They're complementary, not competitors.
FAQ
If I set good Custom Instructions, do I still need FixMyPrompt?
Custom Instructions help your baseline, but they cannot rescue a vague or under-specified prompt for a specific task. They're complementary use both.
Try FixMyPrompt free →
3 free QA reports per day. No signup. No subscription.