By Rami F., Community Manager, B2S · Updated on 7 October 2026 · Reading time: 8 mins

💡 TL;DR: You can validate a start-up idea in just a few days, without writing any code: Perplexity for market research, Claude or ChatGPT to challenge the idea, Figma for prototyping, Framer or Durable to gauge interest, IdeaProof or AI Proof to get a second opinion. These tools minimise guesswork, without replacing real customers.

Here's what you'll wish you'd known before writing a single line of code: one of the biggest risks for a start-up isn't technical – it's building something that nobody wants.

A lack of market need ranks among the top two causes of failure in the analysis of start-up post-mortems published by CB Insights (42 per cent in the most frequently cited version). Bear in mind the scope of this figure: the sample comprises just over a hundred tech start-ups, and several causes may overlap. The order of magnitude remains useful: The time and money spent on development before validation is the riskiest expenditure.

Here are the steps to follow, the prompts to copy and the limitations of each tool.

How can you validate a start-up idea using AI?

Select in this order, from the cheapest to the most time-consuming:

1. Understanding the market : Who's already doing what, and for whom? (Perplexity)

2. Structuring and challenging the idea : Which assumptions are the riskiest? (Claude or ChatGPT)

3. View the product : What does the user journey look like? (Figma)

4. Measuring actual demand : Do strangers leave their email addresses? (Framer or Durable)

5. Get a second opinion : a score and a map of the competitors (IdeaProof, Preuve AI)

1. Perplexity AI: how do you carry out market and competitor research?

Perplexity searches the web in real time and provides each answer with numbered citations that link back to the original sources. Its mode In-depth Research It goes one step further: it carries out dozens of searches, reads hundreds of sources and produces a report in 2 to 4 minutes, whereas a human would take hours to do the same.

How is this useful for a start-up idea:

• validate your initial assumptions (market size, trends);

• identify direct and indirect competitors;

• refine your positioning by seeing what others are already promising.

Copy prompt:

Who are the existing players in [problem or market] in [country / region]

Who are the existing players in [problem or market] in [country / region]

Who are the existing players in [problem or market] in [country / region]

The limit: Don't take the citations at face value. Several analyses suggest that Perplexity may rely on low-quality sources or cite sources that do not actually support the claim. Click on the links for the figures that are relevant to your decision.

2. Claude or ChatGPT: which prompt should you use to validate an idea in a structured way?

An assistant such as Claude or ChatGPT won't provide you with reliable market data on its own, but it excels at organise your thoughts, to help you identify the hidden assumptions behind your idea and suggest ways to test them. The pitfall is that they tend to agree with whatever is put to them. You must therefore explicitly ask them to play devil's advocate.

Structured validation prompt to copy:

Think like a sceptical start-up analyst. Here's my idea:
- Problem: [describe]
- Target: [describe]
- Solution: [describe]
- Business model: [describe]
- Current alternatives for customers: [describe]

Think like a sceptical start-up analyst. Here's my idea:
- Problem: [describe]
- Target: [describe]
- Solution: [describe]
- Business model: [describe]
- Current alternatives for customers: [describe]

Think like a sceptical start-up analyst. Here's my idea:
- Problem: [describe]
- Target: [describe]
- Solution: [describe]
- Business model: [describe]
- Current alternatives for customers: [describe]

What you get: a clearer understanding, different perspectives (especially if you compare the responses of two assistants), identified risks and a clear action plan.

3. Figma AI: how can you prototype an idea in just a few minutes?

Before going into more detail, show your idea. With Figma Make, you describe a screen or user flow in natural language ('3-screen onboarding with registration') and the tool generates wireframes or a clickable prototype that you can test and refine. Figma also offers the ability to generate initial mock-ups from a description, and the option to link multiple screens within a prototype.

What is it for?:

• turn an idea into visuals that can be shown to real users;

• generate interface components and iterate more quickly;

• identify any missing or unclear screens before hiring a developer.

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Limitations: The generated customer journeys use generic components that can be adapted to your brand, and they do not connect to live systems (payment, stock, database). A prototype tests the understanding, not the value.

4. Framer or Durable: how can you gauge actual demand using a landing page?

This is the most important stage: the one where strangers take action, rather than just giving you a polite reply.

• Framer It generates an initial site structure (sections, headings, text) based on a prompt, which you can then refine visually. Forms, SEO, hosting and publishing are all integrated. This is the tool we use at B2S for our own websites.

• Sustainable In around 30 seconds, it generates a complete website with text, images and a contact form, aimed primarily at small businesses. Its free service allows you to build and share a private preview; please check the terms of publication before using it for a public test.

What to measure:

• the enrolment rate (visitors who provide their email address);

• the click on the main button ('Book', 'Join the waiting list')

• Ideally, a intention to pay (price shown, pre-order).

Three rules to ensure the test is meaningful:

1. Set your pass mark before you start (for example, X per cent of enrolments). Otherwise, you will interpret the figures in whatever way suits you.

2. Drive traffic from your actual target audience (online communities, LinkedIn, targeted advertising), not your friends: their opinions are biased.

3. A landing page only measures interest. An email address left behind does not mean the person is a customer ready to pay.

5. AI validation platforms: IdeaProof, Preuve AI

These platforms act as a automated venture capital analyst : they analyse the market, map out the competition and carry out a comprehensive validation process.

• IdeaProof It analyses an idea against more than 50 criteria and, in around 120 seconds, provides a viability score, a risk assessment, and an analysis of strengths and weaknesses, along with suggestions for improvement or pivoting. A basic analysis is free.

• AI evidence offers a free scan lasting around 60 seconds that queries more than 60 live data sources (Crunchbase, Google Trends, Reddit, Product Hunt, G2) to generate a viability score and map up to 15 competitors. Every claim in the report is linked to its source, making it possible to verify it.

Limitations: These are AI-generated analyses, produced without human input. The scores are estimates, not guarantees of success, and highly unconventional ideas are more difficult for an AI to assess. The accuracy or volume figures highlighted by these tools are provided by their publishers. Use them as Second opinion and lead generation tool, not as a verdict.

What free alternatives and additional tools are available?

Free version: IdeaProof and Preuve AI offer a free basic analysis, whilst Durable provides a free trial limited to a private preview. For Perplexity, Figma, Framer, Claude and ChatGPT, the free trials and their limitations change frequently: please check each provider's website before planning your trial.

Additional tools:

• Google Trends to monitor trends in research interest in your subject area and gauge demand;

• Typeform to send customer feedback questionnaires to your target audience;

• ValidatorAI, another AI validator for quickly testing a hypothesis.

Like the platforms mentioned in the previous section, these tools provide indications, not proof.

What these tools cannot replace

The five tools reduce guesswork. None of them replaces a conversation with genuine prospective customers. Before you decide:

• conduct a few interviews with people from your target group (is the problem real, common, and a source of distress?);

• ask what they are doing today to resolve it, and how much it is costing them;

• try a pre-sale or a concrete commitment where possible.

An AI can tell you that a market exists. Only a customer can tell you that they will pay you.

When should you take the theory test? The checklist

Move on to the development stage when you can answer 'yes' to the following points:

1. The problem is confirmed by interviews with people from your target group.

2. You have mapped out your competitors and you know how you stand out from them.

3. The prototype has been tested and the main routes have been mapped out.

4. The landing page has reached the threshold you had set before the test.

5. You have defined the smallest usable version which part of the product (MVP) to build first.

The tools validate the idea. Now we just need to build what comes next.

Has your idea been approved and do you want to turn it into a real product? Let's discuss it: 20 minutes free →

To find out more, take a look at our technical support (CTO as a Service).

See also: La vérité sur le lancement d'une startup sans cofondateur technique · Les 5 pages qui transforment un visiteur en client

FAQ

How can you validate a start-up idea without coding?

In the following order: market research (Perplexity), formulating hypotheses (Claude or ChatGPT), prototyping (Figma), a landing page with a form to gauge demand (Framer or Durable), followed by interviews with real customers.

Which AI tools should you use to validate a start-up idea?

Perplexity for research, Claude or ChatGPT to structure and challenge the idea, Figma for prototyping, Framer or Durable for the landing page, and IdeaProof or Preuve AI for an automated second opinion.

Can AI validate my idea on its own?

No. AI helps to analyse the market and structure your assumptions, but its scores are still just estimates. Validation relies on evidence from real customers: interviews, sign-ups and pre-orders.

Do you need a landing page before developing an MVP?

This is strongly recommended. A landing page allows you to gauge genuine interest (sign-ups, clicks) before investing in development. Set a success threshold before running the test.

How long does it take to validate an idea?

AI tools deliver their analyses in a matter of minutes, but proper validation (interviews, landing page testing, prototyping) usually takes anywhere from several days to a few weeks, depending on the idea and your access to your target audience.

Is Perplexity a reliable tool for market research?

This is a good starting point, as each answer provides links to its sources. However, independent analyses suggest that the citations may be of poor quality or may not support the claim. Check the figures that are relevant to your decision at the source.

Is IdeaProof reliable?

This is an AI-generated analysis, produced without human input: the viability score is an estimate. It is useful for initial screening and identifying areas for improvement, but not for deciding whether to invest. Supplement it with interviews with real customers.

What free tool can you use to test a start-up idea?

IdeaProof and Preuve AI offer a free basic analysis, whilst Durable offers a free service limited to a private preview. The limitations of these free services change frequently: please check them on each provider's website.

Sources

• CB Insights, The Top 12 Reasons Why Start-ups Fail (analysis of start-up post-mortems)

• Perplexity, How does Perplexity work? (quotes and Deep Research mode)

• Perplexity, Introducing Perplexity Deep Research

• Figma, AI wireframe generator in Figma Make

• Gupta, Top 5 AI Research Tools 2026 and Pure AI Labs, Perplexity AI (Limits on quotations from Perplexity)

• Builder.io, Prototyping with Figma AI (limitations of the generated prototypes)

• Framer, AI website builder

• Durable, AI website builder

• IdeaProof, ideaproof.io

• AI evidence, Idea validation tool

• Cambium, Idea validation tools for founders (additional tools: requests, customer feedback, AI validators)