Support

Open the Lab and tap atoms onto the canvas, then draw bonds between them; hydrogens are added for you. You can also use Import to enter a SMILES string (CCO), a formula (C2H6O, which lists its isomers) or the name of a library molecule, or open one of the 86 molecules in the Library and edit it. The 3D model updates as you build.

The Lab checks the structure as you build. If an atom has the wrong number of bonds for its element and charge, it is flagged and the message says what is wrong and how to fix it, for example by adding hydrogens or a charge. Fix that atom (or add a charge) and the 3D geometry is generated again.

The app’s own chemistry engine works out the VSEPR shape from the bonds and lone pairs around each atom, builds the 3D geometry and then measures it. Every value is labeled Reference, Calculated, Model or Illustrative, so you can see where it comes from. Measured angles can differ slightly from textbook values; that is real chemistry, and the explanation says why.

Yes. Open SMILES, MOL, SDF, XYZ and PDB files, or Chemistry 3D projects, from Files, the share sheet or File › Open on Mac. Files up to 5 MB and up to 50 records in an SDF are supported.

Free: the Lab with live 3D, VSEPR and polarity, all 118 elements with three trends and orbitals up to n = 3, reactions with energy diagrams and two mechanisms, the six simulations (core scenarios), all 11 calculators, 9 of the 12 lessons, the glossary, 10 projects and 10 AI explanations a day, and PNG, SMILES and MOL export. Pro unlocks every molecule, reaction and mechanism, all trends and higher orbitals, every simulation scenario, advanced calculator modes, all lessons, unlimited projects and AI explanations, more export formats and Presentation Mode. On Android, Chemistry 3D is free with ads and has no purchases; extra items open when you choose to watch two short ads.

No. The free version has no time limit, so you can use it as long as you like before deciding.

Open Settings and tap Restore Purchases at the top, while signed in with the Apple Account you bought with. One purchase covers iPhone, iPad, Mac, Apple Vision Pro and Apple Watch. If a purchase is waiting for approval (for example Ask to Buy), Pro unlocks as soon as it is approved. If it still does not appear, write to us with the date of purchase; we cannot see your account, so the receipt email from Apple helps.

Settings › Manage Subscription in the app, or Subscriptions in your Apple Account settings. Cancel at least 24 hours before the period renews; Pro stays on until the end of the period you paid for. Lifetime is a one-time purchase and never renews. If you bought Lifetime while subscribed, turn off the subscription so you are not charged again.

Purchases are made with Apple, so refunds are handled by Apple. Request one at reportaproblem.apple.com.

Check that every device is signed in to the same Apple Account, that iCloud Drive is on, and that Settings › iCloud sync is on in Chemistry 3D. The Status row there shows whether the app is using iCloud. Sync needs a connection and can take a few minutes; leaving the app open on the device that has the changes helps.

Deleted projects wait in Recently Deleted for 30 days. Open Projects, find Recently Deleted and restore it.

Yes: on Android phones, tablets and foldables with Android 10 or later, from Google Play. It is free with ads and has no purchases. Some extra lessons, reactions, simulation scenarios and tools open when you choose to watch two short ads: lessons, reactions and scenarios stay open for good, and tools such as Solve all or Word and video export stay on for 24 hours. A Pro purchase on the App Store does not carry over to Android, and projects move between devices as .chem3d files.

Open Settings › Privacy choices in the app. In the European Economic Area, the United Kingdom and Switzerland you can accept or refuse personalized ads there at any time, and where US state privacy laws require it you can opt out of the sale or sharing of personal information for ads. You can also reset or delete your advertising ID in Android’s settings. The Privacy Policy explains what Google collects.

AI explanations are written on the device by Apple Intelligence. If your device does not support it, or it is turned off in your device settings, Chemistry 3D shows curated explanations instead. Turn on Apple Intelligence in your device’s settings, and check that AI explanations are on in Settings › Apple Intelligence in the app. On Android, the Explain panel is built on the device from the numbers the app’s chemistry engine calculated.

Chemistry 3D starts in US English. Open Settings › Language and choose one of the 20 languages; the app reloads in that language. Arabic uses a right-to-left layout.

It has the periodic table with element details, rotating 3D molecules you turn with the Digital Crown, quick molar mass, pH and gas-law tools, and Element of the Day and Molecule of the Day complications. Install it from the Watch app on your iPhone.

Presentation Mode (Pro) hides the controls, enlarges labels and shows the model full screen. On iPad, connect to a display or use AirPlay; on Mac it opens in its own window you can move to a projector.

Yes. It follows your system settings for Reduce Motion, Reduce Transparency, Increase Contrast and text size, supports VoiceOver, and offers high-contrast and color-blind-safe element colors in Settings. Simulations can use fewer particles.

Yes. Everything works without a connection except iCloud sync and buying or restoring Pro; on Android, ads and opening items by watching ads need it too.

Use Report an error on the item in the app, or email us with the molecule, element or reaction and a screenshot. Wrong chemistry is the bug we fix first.

Large molecules and busy simulations use more power. Turn on Settings › Fewer particles in simulations, close other apps, and make sure your device is up to date. If it persists, tell us your device model and what you were doing.