I Tried ChatGPT, Claude, and Gemini with the Same Prompt Formula. The Results Surprised Me.

Same prompt. Three tools. Three completely different personalities.I run a digital marketing agency. AI tools are part of my daily workflow.At some point, I stopped switching between ChatGPT, Claude, and Gemini randomly and started paying attention to what each one actually does differently. Same…

Same prompt. Three tools. Three completely different personalities.I run a digital marketing agency. AI tools are part of my daily workflow.At some point, I stopped switching between ChatGPT, Claude, and Gemini randomly and started paying attention to what each one actually does differently. Same prompt. Three tools. Three completely different outputs.That difference matters more than most people realise. Picking the wrong tool for the wrong task is why so many marketers get mediocre AI output and blame the prompt.I tested all three with the same structured marketing prompt. Here is what I found.The Prompt Formula I UsedBefore comparing the tools, the prompt structure matters. A weak prompt produces weak output across all three tools. The differences only show up when the prompt is strong enough to reveal each model’s personality.I used a six-part formula for every test. Task, Context, Exemplars, Persona, Format, and Tone. Same structure. Same brief. Only the tool changed.The test prompt was this:“You are a digital marketing expert writing for small business owners. Write a LinkedIn post announcing an AI-powered SEO audit service. Tone is confident and direct. Under 150 words. End with a question that invites comments. Reference one real pain point business owners have with SEO.”Simple brief. Clear constraints. Enough room for each tool to show its character.ChatGPT: The ConversationalistChatGPT produced output that felt immediately polished and ready to post. The tone was warm, the structure was clean, and it followed every instruction in the brief.But here is what I noticed. ChatGPT plays it safe. The LinkedIn post it produced was good but predictable. It hit every point in the brief without surprising me once. The pain point it referenced was generic. The question at the end was the kind you see on every LinkedIn post.ChatGPT is the strongest tool for conversational content, storytelling, and anything where you need something that sounds natural and human immediately. It is the fastest path from prompt to usable first draft.Where it falls short is originality. If you want content that sounds like everyone else on LinkedIn, ChatGPT will get you there efficiently. If you want something that stops the scroll, you need to push it harder with more specific constraints or rewrite the output yourself.Best for: Social media captions, email copy, blog post drafts, conversational content that needs to sound natural fast.Claude: The Strategic ThinkerClaude approached the same brief differently. The output was longer than requested, which told me something immediately. Claude reads the brief and then thinks about it before responding rather than pattern matching to the most likely output.The LinkedIn post Claude produced had a more distinct point of view. It did not just announce the service. It made an argument for why most business owners are doing SEO wrong before introducing the solution. That structure was not in the brief. Claude added it because it made the post more persuasive.Claude is the strongest tool for anything that requires reasoning, analysis, or strategic thinking. When I brief Claude on a campaign challenge or a client positioning problem, the output goes deeper than the other tools. It questions assumptions in the brief and surfaces angles I had not considered.The trade-off is length and precision. Claude often gives you more than you asked for. For marketing output where word count and format matter, you need to be more specific in your constraints or edit the output more heavily.Best for: Strategy documents, long-form content, campaign briefs, anything where depth and reasoning matter more than brevity.Gemini: The Search NativeGemini produced output that was noticeably different from both ChatGPT and Claude. The LinkedIn post it wrote was structured for discoverability. It used phrases that read like search queries. The pain point it referenced was specific and data-backed rather than generic.This makes sense when you understand what Gemini is built on. Google’s models are trained with search in mind. Gemini thinks about how content will perform in a discovery context, not just how it reads in isolation.For marketing content that needs to be found, Gemini has a natural advantage. Landing page copy, SEO focused blog content, product descriptions- anything where the words need to match how people search. Gemini instinctively writes for that context.Where Gemini feels weaker is in creative and conversational tasks. The LinkedIn post it produced was technically strong but felt slightly mechanical compared to ChatGPT and Claude. It prioritised clarity and keyword relevance over voice and personality.Best for: SEO content, landing pages, search-optimised copy, product descriptions, anything where discoverability matters as much as readability.What the Experiment RevealedRunning the same prompt across all three tools taught me something I did not expect.The tool is not neutral. Each one has a personality that shapes the output regardless of how precise your prompt is. ChatGPT optimises for natural conversation. Claude optimises for depth and reasoning. Gemini optimises for search and discoverability.Most marketers pick one tool and use it for everything. That is the mistake. The right approach is matching the tool to the task the same way you match the right channel to the right audience.Use ChatGPT when you need something that sounds human fast. Use Claude when you need something that thinks deeper than the brief. Use Gemini when you need something that performs in search.The prompt formula stays the same across all three. What changes is which tool you run it through and why.The Prompt Formula That Works Across All ThreeTask. Context. Exemplars. Persona. Format. Tone.Every strong prompt I have written for marketing work includes all six. The task tells the model what to produce. The context tells it who the audience is and what they care about. Exemplars show it what good output looks like. Persona assigns a role. Format defines the structure. Tone sets the voice.A well-structured prompt reveals each tool’s strengths. A weak prompt makes all three look the same. Mediocre.The difference between ChatGPT, Claude, and Gemini is not which one is best. It is which one is best for what you are trying to do right now.Match the tool to the task. Structure the prompt properly. Then judge the output.What tool do you reach for first when you open an AI tool for marketing work? Drop it in the comments.This story is published on Generative AI. Connect with us on LinkedIn and follow Zeniteq to stay in the loop with the latest AI stories.Subscribe to our newsletter and YouTube channel to stay updated with the latest news and updates on generative AI. Let’s shape the future of AI together!I Tried ChatGPT, Claude, and Gemini with the Same Prompt Formula. The Results Surprised Me. was originally published in Generative AI on Medium, where people are continuing the conversation by highlighting and responding to this story.

Source: Generative AI Pub — Published August 10, 2026 at 10:00 UTC — Category: Image AI