Prompt Optimizer
Paste a prompt you already use and get a sharper version for ChatGPT, Claude or Gemini, with a note on every change. Free, no sign-up.
Starting from an idea instead? Write a new prompt
Related prompt tools
Before and after
Two authored examples: a rough request turned into a clear ChatGPT prompt, and a one-line support bot turned into a Claude system prompt with a fixed reply shape.
An Etsy listing
ChatGPTUser promptClearerBefore write me a product description for my candle its handmade soy and smells like fig, make it good for etsy and not too long and also seoAfter Write an Etsy product description for a handmade soy candle that smells of fig. Details: - Product: [CANDLE NAME], [SIZE AND BURN TIME] - Scent: fig, with [OTHER NOTES, IF ANY] - Buyer: someone shopping for a cosy gift or for their own home Requirements: - 80 to 120 words, warm and specific, no hype words such as "perfect" or "amazing". - Use the phrases "soy candle" and "fig candle" once each, where they read naturally. - Say that it is handmade and give one detail about how it is made. Output: a title under 140 characters, then the description, then 5 Etsy tags separated by commas.- Put the task and the product in the first line.
- Turned "not too long" into a word range the model can hit.
- Replaced "seo" with the exact phrases to use and where.
- Added placeholders for facts only you know, so nothing is invented.
- Asked for a title and tags too, the parts Etsy search reads.
A support bot
ClaudeSystem promptStructured outputBefore You are a helpful support bot for our app. Answer questions about billing. Be nice.After You are the billing support assistant for [APP NAME]. You answer questions about plans, invoices, refunds and payment methods. <rules> - Answer only billing questions. For anything else, say you handle billing and point to [SUPPORT EMAIL]. - Use only the facts in <billing_policy>. If the answer is not there, say so and offer to pass the question on. - Never promise a refund or a discount; explain the policy and the next step. - Be friendly and brief. </rules> <billing_policy> [PASTE YOUR PLANS, PRICES AND REFUND POLICY] </billing_policy> <output_format> 1. A one-sentence answer. 2. Up to three steps the user can take, as a numbered list. 3. One line starting "Need more help:" when a person must step in. </output_format>- Named the scope, so off-topic questions get a clear redirect.
- Gave the assistant a policy block to answer from instead of guessing.
- Ruled out promises the support team could not keep.
- Fixed the reply shape so every answer reads the same way.
Pick what better means
A better prompt depends on what is wrong with the one you have. Each goal is a different edit, and the notes under the result say what was done.
- Clearer
- Keeps the length and removes the guesswork: the task moves to the first line, vague words become specific ones and the answer format is named.
- Shorter
- Cuts repetition, polite filler and instructions the model follows anyway. Every requirement, placeholder and format rule stays.
- More detailed
- Adds what the model needs to tailor the answer: audience, context, limits and edge cases, with [PLACEHOLDERS] for facts only you know.
- Structured output
- Asks for an exact answer shape: fixed sections, a numbered list, a table or JSON with named fields, and what to write when something is missing.
User prompts and system prompts
The same words do different jobs in a chat message and in the instructions behind an assistant. Tell the optimizer which one you pasted.
- User prompt
- One message you send in a chat. The rewrite stays a request in your voice, asking for one result.
- System prompt
- The standing instructions behind a custom GPT, a Claude project, a Gemini Gem or your own app. The rewrite covers role, scope, rules, how to handle unclear requests and the reply format.
How to use the prompt optimizer
Three steps from the prompt you have to one that works on the first try.
- 11. Paste your promptA chat message or a system prompt you already use, up to 6,000 characters. Rough is fine.
- 22. Pick the assistant, type and goalChoose ChatGPT, Claude, Gemini, DeepSeek, Grok and Any assistant, then User or System prompt, then the goal: clearer, shorter, more detailed and structured output.
- 33. Compare, copy or saveRead the before and after side by side with a note on each change. Copy it, improve it again, or save it as a template on your account.
Frequently asked questions
What people ask before they paste a prompt.
1What does a prompt optimizer do?
It takes a prompt you already wrote and rewrites it so the model has less to guess: the task up front, the context it needs, clear limits and an exact answer format. You also get a short list of what changed and why, so you can see the pattern and use it in the next prompt you write.
2Is it free?
Yes. You get 10 free runs a day on each device without an account, and 20 a day with a free account. The optimizer shares that allowance with the other prompt tools, and paid plans remove the daily limit.
3What is the difference between a user prompt and a system prompt?
A user prompt is one message you send in a chat. A system prompt is the set of standing instructions behind a custom GPT, a Claude project, a Gemini Gem or an app, and it applies to every message. Pick the type so the rewrite keeps the right shape: a request for one answer, or rules for a whole conversation.
4Which assistants can it optimize for?
ChatGPT, Claude, Gemini, DeepSeek, Grok and Any assistant. ChatGPT: role, task, context and a clear output format. Claude: xml-tagged context, instructions and output. Gemini: task first, inputs, steps and format. DeepSeek: goal, constraints and checks, no role play. Grok: direct task, voice and source limits. Any assistant gives a plain structure that works everywhere.
5Will it change what my prompt asks for?
No. It keeps your intent, facts, names, numbers and examples. Where the model would need a fact only you know, such as your audience or product details, it adds a placeholder in square brackets instead of making one up.
6How do saved templates work?
With a free account, Save as template keeps the improved prompt on your account together with its target and type. My templates, next to the options in the box, loads one back so you can reuse it or improve it again. You can keep up to 100 templates and delete any of them.
7Do you keep the prompts I paste?
The prompt is sent to our AI model provider to write the new version and is not shown to anyone else. Nothing is kept on your account unless you save it as a template, and templates are visible only to you.
Improve the prompt you already use
Free, 10 a day, no sign-up. Paste it, pick the goal, then compare the two versions.
Paste a prompt