Structo

Structo is a chemical structure editor built for students, educators, and anyone who needs to draw clear, accurate chemical structures on the go. Sketch molecules, reaction schemes, and mechanisms with a fast, intuitive touch interface — no desktop required. FEATURES Structure Drawing - Draw bonds, rings, and functional groups with the clean, textbook-style conventions used in published chemical literature - Automatic valence correction when substituting elements - Clean Structure tool to instantly tidy up rings and spacing - Full stereochemistry support: wedge/dash bonds, explicit hydrogens on stereocenters, and automatic handling of ring vs. exocyclic double bonds Built-In Templates Insert ready-made structures from a wide library covering: - Common rings and scaffolds - Steroids - Sugars - Nucleobases - Alkaloids and neurotransmitters - Pharmaceuticals - Heterocycles - And more All templates use standard 2D coordinates, so your structures look textbook-accurate every time. Reaction Tools - Forward and equilibrium reaction arrows - Curved (mechanism) arrows for showing electron movement - Lone pair markers - A reaction-condition picker for common reagents and conditions above and below the arrow, with subscript/superscript support Validation Dashboard - Instantly check your structure for common drawing errors - Jump directly to flagged issues to fix them one by one - Turn Auto-Validate on or off depending on your workflow Analysis & Export - Molecular formula, molecular weight, and monoisotopic mass calculated automatically as you draw - Import and export structures using SMILES notation - Export your structures as PNG, JPEG, BMP, or TIFF images, or copy them directly to your clipboard to paste into other apps Text & Labels - Add and edit atom labels, including isotope notation with partial superscript/subscript formatting - Add text annotations anywhere on the canvas - Rotate, group, and transform labels and annotations freely Built-In Tutorial New to structure drawing apps? A short interactive tutorial walks you through the basics so you can start drawing right away. PRIVACY Structo collects only anonymous, aggregated usage data to help us improve the app — never the chemical structures you create. See our full privacy policy for details. Whether you're studying for an exam, preparing course materials, or just need to sketch a quick structure, Structo gives you a fast and reliable way to do it from your phone or tablet.