Turn one sentence into a finished website or web app: landing pages, calculators, dashboards, mini-tools, games. It runs live in your chat, ready to share or export. No setup, no code.
Every example below is a real page built from a single prompt. Click around, run the numbers, start the timer — it all works right here.
Build a bill-splitter mini-app: enter the bill, pick a tip %, choose how many people, and show the total and per-person amount live. Dark, modern, mobile-friendly.
If it fits on one page and runs in a browser, Twelver can build it.
Bill splitters, mortgage calculators, converters, checklists — logic and UI from one prompt.
Graphs, KPI cards and interactive reports from your data or a description.
Quizzes, flashcards, puzzles and arcade games — with scoring and animation.
Promo pages, forms and clickable prototypes to validate an idea fast.
Data capture with validation, steps and instant results.
Palette generators, timers, spinners, animations — for a site or a deck.
From idea to a working app in three steps.
In plain words: what the app does, how it looks, what should happen on click.
Twelver writes the HTML, CSS and JS and runs it instantly in a safe sandbox next to the chat.
Ask for any change, open a public link, or download the finished .html file.
Not a mockup, not a wall of code — a live result that works immediately.
The app runs in an isolated iframe right in the chat — nothing to install.
“Make the button bigger”, “add dark mode” — change it in words, not code.
Every revision is saved — compare and roll back to any version in one click.
Send a public link and anyone can open the app — no account needed.
Download a self-contained .html and host it anywhere — zero dependencies.
Attach data, a screenshot or a spec and Twelver builds around it.
Twelver does more: it generates images for your app, researches facts on the web and reads your documents — all in the same chat.
Your first site builds right now. After that it’s cheap enough that one plan lasts a long time.