1. Open the editor
Go to the Ejja Chem editor. It works in Chrome, Firefox, Edge or Safari, with no account and nothing to install. Your drawing is saved automatically in your browser.
Shortcut: type a molecule’s name (“caffeine”, “paracetamol”…) in the editor’s search box and the structure draws itself.
2. Draw the carbon skeleton
Pick the bond tool in the left toolbar, then click and drag on the canvas: each segment is a C–C bond. In skeletal formulas, carbons and their hydrogens aren’t written: every corner or line end is a carbon atom.
For a long chain, the chain tool lets you stretch it to the length you need in one move.
3. Add rings
The bottom toolbar has the common rings: benzene, cyclohexane, cyclopentane… Click a ring, then the canvas, or click an existing bond to fuse the ring onto your structure.
4. Place heteroatoms
Pick an element in the right toolbar (N, O, S, Cl…) and click an atom to replace it. The full periodic table opens with the PT button. Implicit hydrogens are added automatically.
5. Multiple bonds and stereochemistry
The bond tool’s menu offers double and triple bonds, plus wedge bonds (solid or hashed) to show stereochemistry.
6. Charges
The A+ and A− tools add a positive or negative charge to the atom you click, for example to draw an ammonium ion or a carboxylate.
7. Clean up and check
The Clean Up button in the top toolbar straightens bond lengths and angles. The status bar at the bottom of the editor shows the molecular formula and molecular weight live: the fastest way to check your structure.
8. Export and share
The Export menu gives you a PNG or SVG image for lab reports and slides, or a SMILES, MOL, SDF or InChI file for databases. The Share button copies a link that reopens exactly your structure.