Vibe coding is building software by describing what you want to an AI model in plain language and accepting the code it writes without reading it, judging only whether the result seems to work. It is a fast way to test an idea or build a throwaway tool. It is not enough on its own for a product that holds customer data or takes payments.

Picture a founder with a scheduling idea for physiotherapy clinics. On Saturday morning they open an AI app builder, type "a booking page where patients pick a slot and the clinic gets an email," and by the afternoon they have a working demo with a calendar, a form and a confirmation screen. They have not read a line of the code. On Monday a clinic owner asks whether patient records are secure and who else can see them. The founder does not know, and the demo cannot answer for them.

What does vibe coding mean?

Vibe coding means letting an AI write the code from your prompts while you steer by trying the result, not by reading or reviewing the code itself. The person directing it may not be a programmer at all.

The term comes from a post on X by AI researcher Andrej Karpathy in February 2025. It opens: "There's a new kind of coding I call "vibe coding", where you fully give in to the vibes, embrace exponentials, and forget that the code even exists." He describes it as "not really coding" ("I just see stuff, say stuff, run stuff, and copy paste stuff, and it mostly works") and adds: "It's not too bad for throwaway weekend projects."

The phrase spread fast. On 6 November 2025 Collins named "vibe coding" its Word of the Year 2025, defining it as "the use of artificial intelligence prompted by natural language to write computer code." That broader sense is how many people use it now, which is why it helps to be precise about what the original meant.

How is vibe coding different from AI-assisted development?

The difference is review: in vibe coding nobody reads or understands the code, while in AI-assisted development a person reviews, tests and can explain everything the AI wrote before it ships. The tools can be the same; the discipline is not.

The developer Simon Willison drew this line in Not all AI-assisted programming is vibe coding (but vibe coding rocks), published on 19 March 2025. He defines vibe coding as "building software with an LLM without reviewing the code it writes," and adds: "If an LLM wrote the code for you, and you then reviewed it, tested it thoroughly and made sure you could explain how it works to someone else that's not vibe coding, it's software development." His own rule for production work is that he won't commit code "if I couldn't explain exactly what it does to somebody else."

Three ways of building with AI, side by side:

• Vibe coding: Who reads the code: nobody. What decides "done": the screen seems to work. Best for: prototypes, demos, personal tools.

• AI-assisted development: Who reads the code: a developer, before it ships. What decides "done": tests pass and the code can be explained. Best for: products with users, data or payments.

• Traditional development: Who reads the code: the developer who wrote it. What decides "done": tests, review and release checks. Best for: the same products, usually at a slower pace.

Which tools do people use for vibe coding?

People vibe-code with AI app builders that turn a prompt into a running web app, and with AI coding assistants inside a code editor or terminal. The first group suits non-developers; the second assumes someone can work with code.

• AI app builders such as Lovable and Bolt generate the whole app, often with a database and hosting attached, from a chat conversation.

• AI coding assistants such as Cursor and Claude Code work inside a codebase and edit files on request. They can be used for vibe coding or for careful, reviewed development; the tool does not decide which.

Which tool a founder picks matters less than whether anyone will review what it produces before real users arrive.

When is vibe coding enough to build a real product?

Vibe coding is enough when the cost of a hidden mistake is small: a prototype to show investors, a landing page to test demand, an internal tool used by a few colleagues, or a demo for customer interviews. It stops being enough once strangers sign up, store data or pay.

Use this checklist. If you answer yes to any question, the product needs review by someone who can read the code:

1. Do people outside your team sign in?

2. Does it store personal, health or financial data?

3. Does it take payments or manage subscriptions?

4. Would a data leak or a wrong charge hurt a customer or break a contract?

5. Will someone other than you need to change it in six months?

6. Does a customer's security review or an investor's due diligence ask who wrote and checked the code?

A prototype that answers no to all six can stay vibe-coded. Before building anything, it is worth checking that people want it at all; our two-week validation test is a cheaper first step than any code.

What goes wrong when a vibe-coded app gets real users?

The usual problems are users seeing each other's data, secret keys exposed in the browser, payments that don't match what the app records, and failures nobody notices. Each one hides in code that nobody read, which is why the demo looks fine.

These failures share one cause: an AI builds what the prompt describes, and prompts rarely describe access rules, key handling or what should happen when a payment webhook arrives twice. Our post on what breaks when an AI-built app gets real users walks through each one with a checklist.

The fix is rarely to throw the app away. Often the screens and flows are a good specification, and the work is to review the data model, access control and payments, then harden what is there. When the foundations are wrong, a staged rebuild is the safer path; our post on whether to fix or rebuild an app you didn't build explains how to decide.

How should a founder use vibe coding well?

Use vibe coding to learn fast, then switch to reviewed development before the product carries real risk. Treat the vibe-coded version as a draft and a specification, not as the finished product.

1. Write down what the app must do in plain sentences before prompting: who uses it, what data it keeps and who may see it.

2. Keep the prototype small. One core journey is easier to review, test and rebuild than ten half-finished ones.

3. Use test data only until someone has checked access rules and secrets. Never load real customer records into an unreviewed app.

4. Own your accounts. Keep the code repository, database, hosting and payment accounts in the company's name from day one.

5. Plan the review before launch, not after the first incident: access control, secrets, payments, error alerts and backups.

How we approach it at Vizio AI

We like vibe-coded prototypes. A founder who arrives with a working demo has already answered many questions a specification would ask, and we treat it as exactly that: a specification that runs.

From there we read the code before we promise anything. We check the data model, access rules, secrets and payment flows, list what is missing for real users, and agree with the founder which parts to keep, which to harden and which to replace. Then we work in stages, keeping the app usable while each part is reviewed and tested, and hand over code, accounts and documentation the founder's own team can run.

This work sits in our Venture Studio. If your AI-built app works in the demo but is not ready for real users, Finish Your Build is where to start.

Sources

• Andrej Karpathy, post on X introducing "vibe coding" (February 2025): https://x.com/karpathy/status/1886192184808149383

• Simon Willison, Not all AI-assisted programming is vibe coding (but vibe coding rocks) (19 March 2025): https://simonwillison.net/2025/Mar/19/vibe-coding/

• Collins, Collins' Word of the Year 2025: AI meets authenticity as society shifts (6 November 2025): https://blog.collinsdictionary.com/language-lovers/collins-word-of-the-year-2025-ai-meets-authenticity-as-society-shifts/

• Vizio AI, Finish Your Build: https://www.vizio.ai/finish-your-build