Get better answers from AI.
Free tools for working with ChatGPT, Claude and Gemini. Fix a weak prompt or start from one of 669 templates, then make the draft sound like you, check its facts and keep private details out of the chat.
Free, with no account to make. Your prompts stay in your browser. New to this? Start here.
Your prompt’s score inside ChatGPT and Claude, with Prompt Score for Chrome
Hide them before this goes into an AI chat.
Read on this page as you type. Nothing is sent anywhere. On a phone, share text here from any app.
What do you need to do?
Pick the job. Each tool does one, and most of them work without an API key.
For building AI into a product: Prompt Linter, Agent Brief Check, Library Audit, Token Counter, AI Cost Calculator, Model Compare, Prompt Tester, Chatbot Safety Test, Version Compare, My Prompts.
Start from a prompt that works
669 expert prompts, grouped by the work they do. Each has blanks for your own facts and a note on how to check the answer, and works in ChatGPT, Claude, Gemini and Copilot.
Before
1/10 Needs work
- Has: What to make
- Missing: Who it's for
- Missing: Background facts
- Missing: Length
- Missing: Format
- Missing: What to avoid
- Missing: What good looks like
- Missing: An example
- Missing: If unsure
- Missing: Layout
After, with what was added marked
6/10 Good
- Has: What to make
- Has: Who it's for
- Has: Background facts
- Has: Length
- Missing: Format
- Has: What to avoid
- Missing: What good looks like
- Missing: An example
- Missing: If unsure
- Has: Layout
Scored with the Grader's ten checks. The strong version leaves blanks for the facts only you know.
Pick your work
- Emails and meetings
- Writing and editing
- Marketing
- Job search
- Sales
- Customer service
- Managers
- HR and recruiting
- Project management
- Research
- Excel and data
- Finance and accounting
- Contracts and legal
- Operations
- Small business
- Teachers
- Product managers
- Coding agents
- System prompts
- Images and video
Packs for the job at hand: a presentation, an assistant’s week, report cards and performance reviews.
Your words go only where you send them
Most AI apps pass your words through their own server and keep a copy. Here, most tools run on your device: thinkhard.si sends the page, and when you run a prompt your browser talks to the AI company directly, with your own key. The engine tools and Pro’s included AI are the exceptions you choose: they send your text to us only when you press their button, and we read it to answer you and keep none of it.
A typical AI app
thinkhard.si
When you press an engine tool’s button
What exactly reaches us, and what stays with you
Kept in your browser
- Your API keys, sent only to the provider they belong to. Turn off “Remember” to keep a key for this tab only.
- Prompts, test suites, runs and grades.
- Drafts and settings. Export everything as one file, or delete it, from Settings.
What reaches thinkhard.si
- The request for each page, as with any website.
- Anonymous daily totals of page views and tool runs. What is counted.
- Text you send with an engine tool’s button or Pro’s included AI: read to answer you, then forgotten. What is sent.
- Your saved work, only if you have Pro and turn on sync.
- Whatever you type into the waitlist, contact or repository unlock form.
No ads and no trackers, and no scripts from other companies except Paddle’s, on the checkout page. An account, and its cookies, only if you sign in. Free keys from Google AI Studio, OpenRouter and Groq make every tool free to use.
Free stays free.
Pro adds included AI runs and sync across your devices for $8 a month when it opens. Team is next: one library of approved prompts, one click away in everyone’s assistant.
Fair questions
Do I need to be technical to use this?
No. If you can write an email, you can use the templates, the Grader’s score and the cost calculator. Underlined words open a plain explanation, and the Start here page points you to the right tool in a minute.
What is an API key, and do I need one?
It is a code from an AI company, such as Google, Anthropic or OpenAI, that lets these tools send your prompt to their model, billed to your own account, usually a fraction of a cent per run. You only need one to run prompts on real models. Google AI Studio, OpenRouter and Groq give free ones. The full explanation.
Is it really free?
Yes. Most tools run in your browser, and the engine behind the rest is light to run, so serving them costs very little. Model calls are billed by your provider on your own key. Google AI Studio, OpenRouter and Groq all give free keys with free models, so you can use every tool without paying anyone.
What does the score out of 10 mean?
A count, not an opinion. A prompt meets ten checks: what to make, who it is for, background facts, length, format, what to avoid, what good looks like, an example, what to do if unsure, and a layout the AI reads well. Each one it covers adds a point. Each score has a thinking level, from Guess at 1, where the AI has to guess nearly everything, to Superintelligent at 10, where it has nothing left to guess.
How will this make money?
Through paid plans for what needs a server. Team, being shaped now, shares a team’s tested prompts inside the AI tools it already uses; a later plan for builders adds scheduled test runs, prompt CI and managed credits. The free tools stay free. See the plans.
Do you train on my prompts?
No. Most tools never send your prompts to us, and the few that do, when you press their button, read them only to answer you and keep nothing. What happens to your prompts at the model provider is set by that provider’s terms. Paid API traffic is generally not used for training, but some free tiers and free models may log or use what you send, so keep sensitive data off free keys and check your provider’s policy.