How Do You Validate a SaaS Idea Before Writing Any Code?

The build-before-validation trap looks like productivity. You are writing code, making decisions, seeing a product come together. What you are actually doing is spending three to six months building something nobody asked for. Validation is the work you do before opening your IDE — and it is the highest-leverage thing you can do with the first weeks of an idea.

The core question you are trying to answer

Validation is not "do people like this idea?" People will say yes to almost any idea when asked directly — it is socially easier than saying no. The question you are trying to answer is: "Will people pay for this, and are there enough of them to build a business?" Those are two separate questions, and both need a yes before you write your first line of code.

Customer interviews before everything

Talk to 10–15 people who match your hypothetical customer profile before building anything. The goal is not to pitch your idea — it is to understand how they currently handle the problem you think you are solving. Ask: how do you currently manage this? What tools do you use? How much time does it take? What does it cost you? Have you tried to fix it? Why did that solution fall short?

Listen for the language they use. Listen for the frequency of the problem. Listen for what they have already tried and paid for. If nobody you speak to has already tried to solve the problem, that is a signal it is not painful enough to pay for. If they all name the same inadequate solution, that is a signal there is a real gap.

Smoke tests and fake doors

A smoke test is a minimal public signal that reveals whether real demand exists before you build. The classic pattern: a landing page with a "Join the waitlist" or "Buy now" button. Drive traffic to it — paid ads, Twitter posts, cold outreach, Reddit comments — and measure click-through rates and email captures. Industry benchmark for a well-targeted audience: 10–20% email capture on landing page visits is a meaningful signal of interest. Below 5% usually means the positioning is wrong or the audience is wrong.

A fake door test takes this further: show a pricing page and a checkout button. When someone clicks through, you capture their email and explain the product is not live yet. This tells you whether the interest survives contact with a price. Do this before spending six months building.

The landing page MVP

Your landing page is a hypothesis made concrete. It should state the problem, the solution, who it is for, what it costs, and include a call to action. Keep it to one page. Use a no-code tool (Framer, Webflow, Carrd) to build it in a day. The goal is not a polished website — it is a written-out version of your pitch that you can put in front of real people and see how they respond. The feedback you get from a landing page review is more useful than the feedback you get from describing the idea verbally, because people react to the concrete version differently.

Pre-selling as the highest bar

Pre-selling — collecting actual payment before building — is the strongest form of validation. "I will build this for you if you pay me £X now" is a much harder question than "would you use this?" and the answers are correspondingly more reliable. Even a handful of pre-sales at a modest price (£50–£150 for access on launch) tells you more about real demand than any number of "great idea!" responses in customer interviews.

If you cannot get five people to pre-pay for the product among your target audience, the probability that you can get 500 people to buy it after building it is low.

Validation benchmarks

Clear signals to look for: 3+ customer interviews where people describe the problem in similar language without prompting. A smoke test landing page converting at 15%+ on targeted traffic. At least 3 pre-sales or paid commitments before building. A specific niche where the problem is acute, the alternatives are clearly inadequate, and you can name 10 companies or people who match the ICP. If you have all four, build. If you have none, you are not ready yet.

The founders who validate first ship faster, waste less, and reach paying customers sooner than the ones who build in a vacuum. Launchstag is a weekly indie product directory where every listing is a permanent indexed page with a dofollow badge — getting your validated product in front of the builder community is the natural next step after your idea survives the validation process. tools.cafe is a curated tool directory with a badge-for-backlink model that adds a permanent, qualified traffic channel to your distribution mix from day one. LaunchBuff is a fortnightly bracket competition with 16 products across 4 rounds over 14 days — community voting is itself a form of real-world validation that reveals how your positioning and value proposition land with an audience of builders and early adopters.