The Alkane
IUPAC name generator: draw a structure, get the name
The Alkane is a free IUPAC name generator built for students. Build an organic molecule atom by atom in the editor above and read off its systematic name underneath, updating as you draw. No sign-up, no install, no cost — and no limit on how many molecules you name.
What does this tool do?
It converts a structure into a name. You draw the molecule and the naming engine works out the parent chain, numbers it, orders the substituents and returns the IUPAC name.
It is built for the part of chemistry that is hardest to practise alone: check your own answer against the machine's instantly, then change one bond to see exactly how the name responds.
How do you name a molecule with it?
- Select an atom, ring or group from the toolbar.
- Select a bond type from the toolbar.
- Choose where to place it — click an available stub to grow the molecule, or an existing atom to replace it.
- Read the name below the canvas. It refreshes as you draw; if a structure falls outside the supported set, the tool says so instead of guessing.
Frequently asked questions
What is an IUPAC name?
An IUPAC name is the systematic name of a compound, built from rules published by the International Union of Pure and Applied Chemistry. Each name describes one organic chemical, and each chemical has exactly one correct name — the names required in organic chemistry exams.
Is The Alkane free?
Yes! Free forever, no account, nothing to install. It runs in the browser and the naming engine is open source. Learn more on the about page.
Why does it say it cannot name my molecule?
Because it names exactly or refuses. If your structure uses a feature outside the supported set, it reports that rather than inventing a plausible-looking name. I built the engine as a deterministic, rules-based algorithm — not a machine-learning model that guesses.
Is there a limit to how many molecules I can name?
No. Draw and name as many molecules as you like — there's no cap, no trial period and nothing to pay for, ever. The only thing I ask in return is that you share it with your friends, classmates and teachers.
Can I use it on a phone?
Yes. The editor is touch-friendly and the layout adapts to small screens.
Can I use the API in my own app?
Yes — the naming engine is open source and free to use; please credit the project and share what you build. A rate-limited API is also available for free, so long as you don't abuse it — see the documentation, and let me know what you build on GitHub!