One printable table of the whole notation: the organic subset and the bracket atoms, the four bond symbols, branches, ring-closure digits, aromaticity, charges, isotopes and the two stereochemistry markers — each with what it draws.
Convert between chemical structures and SMILES in both directions, search a list of structures by substructure or SMARTS, and learn the notation step by step. Everything runs in your browser — no structure you open ever leaves your machine — so the tool needs JavaScript.