What Is Vibe Coding? A Plain-English Explanation
Vibe coding is building software by describing it to an AI and judging the result, not the code. Where it works, where it fails, and how to do it safely.
Mythex Team · · 6 min read
Vibe coding is building software by describing what you want to an AI in plain language, running what it produces, and steering by the results rather than by reading the code. You judge the app — does the button work, does the page look right — and ask for changes until it does what you need. The term was coined by AI researcher Andrej Karpathy in a February 2025 post on X, where he described giving in to the vibes and forgetting that the code exists.
Where the term came from
Karpathy, a founding member of OpenAI and former head of AI at Tesla, used the phrase to describe how he was building small weekend projects: talking to an AI coding tool, accepting its changes without reading the differences, and pasting error messages back in until things worked. He was clear that this suited throwaway projects.
The phrase caught on because it named something many people were already doing. Within months it was being used for everything from hobby projects to startup prototypes, and Collins English Dictionary picked "vibe coding" as its 2025 Word of the Year. Today it is used loosely for any building where the AI writes the code and a person directs it in plain language.
Why it matters if you're building with AI
For people who don't write code, vibe coding is the whole reason AI app builders are useful. A founder can test an idea in an afternoon; a small business owner can build the booking form or stock tracker they could never justify paying an agency for; a designer can turn a mock-up into something clickable.
But the definition contains its own warning. "Forget that the code even exists" is fine when the code only has to work for you, today. It is less fine when the app stores customers' data, takes payments or needs to keep working for years. Knowing where that line sits is the most useful thing you can learn about vibe coding.
An everyday analogy
Think of renovating a kitchen by telling a builder what you want rather than drawing plans yourself. You say "a long counter under the window, open shelves, the fridge near the door," then walk in each evening, look at what's been done, and say what to change.
That works well for the layout and the look. You can judge those just by standing in the room. It works less well for what's behind the walls: the wiring, the plumbing, whether the gas line meets code. You can't see those by looking, and a problem there may not show up until something goes wrong. A careful owner still gets an inspection.
Vibe coding is the same. The screens are the visible room. Security, data handling and how the code is organised are the wiring.
What vibe coding looks like in practice
Say you want a simple tool to track which clients have paid their invoices.
| Step | What you do | What the AI does |
|---|---|---|
| 1. Describe | "A page listing my clients with invoice amount, due date and paid/unpaid status. I can add a client and mark an invoice paid." | Writes the pages, the form and the logic to save entries |
| 2. Try it | Add a client, mark it paid, refresh the page | Runs the app in a preview |
| 3. React | "After a refresh my clients disappear" | Explains that entries were only kept in the browser's memory and adds a database |
| 4. Refine | "Sort overdue invoices to the top and colour them red" | Changes the list |
| 5. Check | Open it on your phone; try an empty form | Fixes what you report |
You never opened a code file. But notice step 3: the app looked finished before it actually saved anything. Vibe coding rewards people who test like a user and describe what they see precisely.
Benefits
- Speed. A working first version in minutes or hours instead of weeks.
- Low cost to try ideas. You can build three versions of something and keep the one that works.
- Direct control. The person who understands the problem is the one shaping the product, with no brief lost in translation to a developer.
- Learning by doing. Many people pick up how apps fit together — frontend and backend, databases, APIs — just by watching what the AI builds and asking why.
The real risks
These are not reasons to avoid vibe coding. They are the things the vibes don't check for you.
Security holes you can't see
An app can look perfect and still let any logged-in user read every other user's records, or expose a secret key in code that runs in the visitor's browser. Neither shows up when you click around as yourself. Common problems include missing permission checks on the server, API keys placed in frontend code, and forms that accept anything.
Code nobody understands
If no one has read the code, no one knows how it is organised. That's fine at small sizes. As an app grows, each change risks breaking something unrelated, and the AI can start "fixing" one bug by creating another. Apps that were vibe coded for months without any review are often harder to change than apps built more slowly.
Not knowing what "done" means
The AI will happily tell you something is fixed. Only testing tells you whether it is. People who skip testing end up with features that work in the demo and fail with real data: long names, empty fields, two people booking the same slot.
Hidden dependencies and costs
AI-built apps often pull in outside services — email providers, payment processors, AI APIs. Each one has its own account, keys, limits and bills. Know what your app depends on before you launch.
Common misconceptions
| Misconception | What's actually true |
|---|---|
| "Vibe coding means there's no code." | There is real code. You just aren't reading it. That's why you can later export it or hand it to a developer. |
| "If it runs, it's correct." | Running and being correct, secure and maintainable are different things. |
| "It's only for non-developers." | Many professional developers vibe code prototypes, then review or rewrite before shipping. |
| "The AI will tell me about problems." | It often will if you ask, but it won't always volunteer them. Ask directly. |
| "You can't build anything serious this way." | Plenty of real apps start this way. The serious part is adding testing and review before real users depend on it. |
How to vibe code responsibly
A few habits cover most of the risk:
- Keep changes small. One request, one change, then test. Big vague requests produce big vague results.
- Use checkpoints. Make sure you can roll back to the last working version before trying something risky.
- Ask the AI to explain. "What does this change do? What could break?" costs little and catches a lot.
- Test as a stranger. Log in as a second user and try to see the first user's data.
- Keep secrets out of code and chat. API keys belong in environment variables or project secrets.
- Review before real users. For anything with payments or personal data, go through a security checklist or get a developer to look.
What to ask your AI builder for
Useful prompts that turn vibes into checks:
- "Before you build this, tell me your plan and what data it will store."
- "List every place this app stores or sends user data."
- "Can a logged-in user see or change another user's records? Check the server code, not just the pages."
- "Are any API keys visible in code that runs in the browser?"
- "What happens if two people submit this form at the same moment?"
- "Summarise what changed in the last three edits."
For more patterns, see how to write prompts for AI app builders and, when things go wrong, how to debug an AI-built app.
Vibe coding with Mythex
Mythex is an AI app builder built for this way of working: you describe the app in chat, the agent writes and runs the code in a live preview, and you publish it to a public URL. A few features exist specifically for the risks above. Plan mode lets the agent lay out an approach before it touches any files, Ask mode answers questions without editing anything, and each successful turn saves a checkpoint you can revert to. On Pro you can open the full code editor, export the project or sync it to GitHub when you want a developer to review it. The chat docs explain the modes and checkpoints, and the templates give you a starting point if a blank page feels like too much.
Questions
Who coined the term vibe coding?
Andrej Karpathy, an AI researcher and a founding member of OpenAI, coined it in a post on X in February 2025. He described giving in to the vibes and forgetting that the code even exists, and the phrase spread quickly from there.
Is vibe coding the same as no-code?
Not quite. No-code tools have you build in a visual editor that hides the code. With vibe coding an AI writes real code that exists in files; you simply choose not to read it and steer by describing what you want and checking the result.
Is vibe coding safe for a real app?
It can be, if you add checks the vibes skip: test that users can't see each other's data, keep API keys in secrets rather than in the code, and review anything that handles money or personal data. For throwaway prototypes the risk is low; for apps with real users it is not.
Do I need to learn to code to vibe code?
No. But knowing the basic ideas — what a database, an API and authentication are — makes your requests clearer and helps you notice when something is wrong. You don't need to write code to understand those concepts.