AI

Prompt engineering toolkit

For anyone who writes prompts for work, from marketers to developers shipping LLM features. We start with free ways to learn and structure prompts, then playgrounds for trying them across models, then open-source tools for testing and optimising prompts at scale.

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   Prompt Engineering GuideOpen sourceA thorough free guide to prompting techniques, with papers and examples.★ 79.8k · MIT
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   PPrompt Structure BuilderBrowser toolAssemble a prompt from role, context, task, constraints, format and examples.
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   PPrompt Quality CheckerBrowser toolPaste a prompt and get specific fixes for missing context, audience or output format.
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   PPrompt Variable Template BuilderBrowser toolTurn a prompt with {{variables}} into a fill-in form, or batch-fill it from CSV rows.
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   Learn PromptingAI toolA free, open guide covering prompting from basics through to security.Freemium
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   Claude ConsoleAI toolAnthropic's Workbench for testing prompts, with a prompt generator built in.Paid
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   Google AI StudioAI toolPrompt Gemini models in the browser and test multimodal inputs.Freemium
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   LMArenaAI toolRun the same prompt against two anonymous models side by side and compare.Free
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   OpenRouterAI toolOne API and chat room for many models, useful for comparing outputs cheaply.Freemium
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    promptfooOpen sourceTest prompts against assertions and red-team LLM apps from the command line.★ 26.7k · MIT
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    DSPyOpen sourceReplace brittle hand-written prompts with declarative programs that can be optimised.★ 38.9k · MIT
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    SStructured JSON outputPromptA prompt pattern for getting reliable JSON back instead of loose prose.Free prompt
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    CCritique and revision loopPromptHave the model critique and revise its own draft before you see it.Free prompt