ChemDraft 1.0.0

macOS (Apple silicon)

ChemDraft 1.0 is the first official release. It brings document tabs, dialogs in their own movable windows, abbreviation labels that count as real chemistry, and a long list of drawing fixes.

• Document tabs. Several drawings open as tabs in one document window. Tabs that could not be restored after a restart can be retried, saved or discarded, and a restored tab saves back to its own file.
• Dialogs are movable windows. Export and Custom Page Size open in their own windows that you can move anywhere, including another monitor. They reopen where you left them, and the floating toolbars stay usable beside them. Simple questions use the system's own message boxes.
• Export preview and size presets (optional). Turn on Settings ▸ Export preview and size presets to see a live preview in the Export window, with size presets, width and height in pixels or millimetres, and DPI. Off by default; exported files are the same either way.
• Save before quitting (optional). Settings ▸ Ask to save unsaved changes before quitting.
• Abbreviation labels are chemistry. Labels such as OMe count toward the formula and mass and export correctly, and a label typed on a ring atom becomes a substituent.
• Labels behave. Typing NH no longer turns into nihonium, OMe is no longer cropped while you type it, Escape cancels a whole typed label, and group labels meet their bond at the atom they bond to.
• Drawing fixes. Chain and arrow drags that start on an object follow the pointer, the eraser removes only what it touches, Escape cancels a drag in progress, ring placement never leaves an over-valent atom, and pages with many overlapping rings no longer freeze the app.
• Canvas matches export. Objects are painted in document order, as in exported files, and ring fills are notched around ring-atom labels.
• Floating toolbars and panels. They keep their stacking order after a system dialog, show an edge where they overlap, and plugin panels take keyboard focus only on their own inputs. Dragging a toolbar or panel by its title follows the pointer exactly.
• Export. PDF export embeds open-licence fonts for symbols the standard fonts can't show, raster export runs off the main thread and refuses drawings too large to render, and CDXML import reads every element by atomic number.
• macOS. Quit and Cmd+Q save the session before the app exits, and opening a document while ChemDraft is closed no longer crashes it.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

Windows

ChemDraft 1.0 is the first official release. It brings document tabs, dialogs in their own movable windows, abbreviation labels that count as real chemistry, and a long list of drawing fixes.

• Document tabs. Several drawings open as tabs in one document window. Tabs that could not be restored after a restart can be retried, saved or discarded, and a restored tab saves back to its own file.
• Dialogs are movable windows. Export and Custom Page Size open in their own windows that you can move anywhere, including another monitor. They reopen where you left them, and the floating toolbars stay usable beside them. Simple questions use the system's own message boxes.
• Export preview and size presets (optional). Turn on Settings ▸ Export preview and size presets to see a live preview in the Export window, with size presets, width and height in pixels or millimetres, and DPI. Off by default; exported files are the same either way.
• Save before quitting (optional). Settings ▸ Ask to save unsaved changes before quitting.
• Abbreviation labels are chemistry. Labels such as OMe count toward the formula and mass and export correctly, and a label typed on a ring atom becomes a substituent.
• Labels behave. Typing NH no longer turns into nihonium, OMe is no longer cropped while you type it, Escape cancels a whole typed label, and group labels meet their bond at the atom they bond to.
• Drawing fixes. Chain and arrow drags that start on an object follow the pointer, the eraser removes only what it touches, Escape cancels a drag in progress, ring placement never leaves an over-valent atom, and pages with many overlapping rings no longer freeze the app.
• Canvas matches export. Objects are painted in document order, as in exported files, and ring fills are notched around ring-atom labels.
• Floating toolbars and panels. They keep their stacking order after a system dialog, show an edge where they overlap, and plugin panels take keyboard focus only on their own inputs. Dragging a toolbar or panel by its title follows the pointer exactly.
• Export. PDF export embeds open-licence fonts for symbols the standard fonts can't show, raster export runs off the main thread and refuses drawings too large to render, and CDXML import reads every element by atomic number.
• Windows. The NMR Shift Predictor plugin now works on Windows, closing the document window quits within seconds after saving, Ctrl+W on the last drawing leaves a blank one, status hints name Alt instead of Option, and saving to a file another program briefly holds now retries instead of failing.

ChemDraft 0.3.9

macOS (Apple silicon)

ChemDraft now explains analyses that can't run, and is stricter about chemistry it can't read faithfully.

• Analyzer notices. When an analysis can't run (for example Analyze ▸ Analyze Mass / m/z with no molecule, or two, selected), a notice at the bottom left now says why. It stays up while you point at it, and closes on its own or with ×.
• Clearer SMILES paste errors. When pasted SMILES can't be drawn, ChemDraft pastes it as text and the status line says why.
• No invented radicals. If RDKit is unavailable and ChemDraft reads SMILES with OpenChemLib instead, an aromatic ring that can't be drawn as written (for example n1cccc1, which needs [nH]) is refused with an explanation instead of being drawn with an unpaired electron.
• Unknown bonds are not exported as single bonds. A bond whose order ChemDraft doesn't know (for example from an imported file) now stops SMILES export for that structure and names the bond. Structure-list exports report it and continue with the rest.
• Less work at startup with OpenChemLib. If Spin 3D is set to OpenChemLib, ChemDraft no longer loads RDKit in the background after launch.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

Windows

ChemDraft now explains analyses that can't run, and is stricter about chemistry it can't read faithfully.

• Analyzer notices. When an analysis can't run (for example Analyze ▸ Analyze Mass / m/z with no molecule, or two, selected), a notice at the bottom left now says why. It stays up while you point at it, and closes on its own or with ×.
• Clearer SMILES paste errors. When pasted SMILES can't be drawn, ChemDraft pastes it as text and the status line says why.
• No invented radicals. If RDKit is unavailable and ChemDraft reads SMILES with OpenChemLib instead, an aromatic ring that can't be drawn as written (for example n1cccc1, which needs [nH]) is refused with an explanation instead of being drawn with an unpaired electron.
• Unknown bonds are not exported as single bonds. A bond whose order ChemDraft doesn't know (for example from an imported file) now stops SMILES export for that structure and names the bond. Structure-list exports report it and continue with the rest.
• Less work at startup with OpenChemLib. If Spin 3D is set to OpenChemLib, ChemDraft no longer loads RDKit in the background after launch.
• Update notes read cleanly. The update dialog now shows release notes as plain text, without stray formatting marks.

ChemDraft 0.3.8

macOS (Apple silicon)

ChemDraft can now send bug and crash reports straight from the app.

• Report a Bug. Help ▸ Report a Bug… opens your own email program with a report already started, including your ChemDraft version and computer type. Nothing is sent until you press Send.
• Crash reports. If ChemDraft runs into an error, or shut down last time because of an internal error, it offers to email a crash report with the details filled in. You can read the email before sending, or say Not Now.
• Typing goes back to your drawing after hiding the app (Mac). After ⌘H and returning to ChemDraft, typing goes to the drawing again instead of an open report window.
• Plain window title. The released app's window title now reads simply "ChemDraft".

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

Windows

ChemDraft can now send bug and crash reports straight from the app.

• Report a Bug. Help ▸ Report a Bug… opens your own email program with a report already started, including your ChemDraft version and computer type. Nothing is sent until you press Send.
• Crash reports. If ChemDraft runs into an error, or shut down last time because of an internal error, it offers to email a crash report with the details filled in. You can read the email before sending, or say Not Now.
• Plain window title. The released app's window title now reads simply "ChemDraft".

ChemDraft 0.3.7

macOS (Apple silicon)

ChemDraft now runs on Windows, and large drawings are much faster to edit, save and reopen.

• ChemDraft for Windows. The first Windows release, for Windows 10 and 11 (x64). It installs per user with no administrator rights and updates itself after asking you first. Everything you know from the Mac version is there, with Ctrl-based shortcuts.
• Large drawings stay responsive. Rotating, moving, aligning or deleting thousands of selected objects now takes about as long per object as editing a few, rather than slowing down sharply as the selection grows. Saving is faster, undo history no longer grows without limit, and very large files open again after saving.
• More of CDXML comes through. Groups and dative bonds in CDXML files are kept, and a file that cannot be opened says why. Damaged or hostile CDXML files are refused safely instead of stalling the app.
• Keyboard shortcuts fixed. Group, Bring to Front, Bring Forward, Send Backward and Send to Back work from the keyboard again.
• Plugins read labels as drawn. Condensed labels such as OH and NH2 reach plugins (the NMR predictor included) the way they appear on the page.
• Faster toolbars at launch. The toolbars appear sooner after opening the app.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

Windows

The first Windows release of ChemDraft.

• Windows 10 and 11, x64. Installs for your user account only; no administrator rights needed.
• The installer is not yet code-signed. The first time you run it, Windows SmartScreen warns you. Choose More info, then Run anyway.
• Updates itself, after asking. ChemDraft checks for a new version at most once a day and asks before installing. File ▸ Check for Updates… checks at any time. Your open drawing is saved and restored across the update.
• Large drawings stay responsive. Editing, saving and reopening drawings with thousands of objects is much faster.
• More of CDXML comes through. Groups and dative bonds are kept, and damaged files are refused safely with a reason.
• Known quirk: the Redo menu item shows Ctrl+Shift+Z; Ctrl+Y works as well.

ChemDraft 0.3.6

Structure recognition from images (experimental), floating report windows, and correct counting of aromatic rings.

• Recognize a structure from an image (experimental). Install the official MolScribe OCSR plugin from the Plugin Manager in one click; ChemDraft sets up its local recognition engine for you. Choose an image file or drag out a region of the screen, watch progress in a card you can cancel, and review the proposed structure before it is inserted. Nothing is added to your drawing until you accept it. Recognition runs on your Mac; Apple silicon only.
• Analysis and plugin reports open in their own windows. Reports float beside your drawing, stay inside the visible screen area, and can be moved, copied, exported and closed with ⌘W.
• Aromatic rings count correctly. Structures pasted with aromatic bonds (MOL files with aromatic bond types, or CDXML) now give the right formula (benzene is C6H6, not C6H12), draw pyrrole-type nitrogens as NH, and export readable molfiles. Where a file does not say which nitrogen carries a hydrogen, ChemDraft makes its best reading and marks the atom so you can check it; hover the mark for the reason. Hydrogen counts stated in CDXML are kept.
• 3D rotation reports what it changed. Rotating a 3D model now tells you when committing the rotation had to simplify part of the structure.

Documents saved with this version that keep a CDXML hydrogen count open in 0.3.6 or later.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

ChemDraft 0.3.5

Fixes for atom-label typing and for Undo/Redo in the Edit menu, both reported by testers.

• Typing a substituent no longer erases it. If the label box lost focus while you were typing (for example, when a palette window briefly took focus), your remaining keystrokes could act as tool shortcuts: e armed the eraser, element letters replaced the label with a single atom, and Backspace stripped it. The label box now keeps focus, Tab finishes the label like Return, and the edited atom is no longer left selected when editing ends.
• Edit ▸ Undo and Edit ▸ Redo now undo your drawing. The menu items (⌘Z and ⇧⌘Z) previously reached only text-field undo. They now undo and redo drawing changes. In a text field, including text fields in palette windows, they still undo your typing.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

ChemDraft 0.3.4

ChemDraw-style keyboard shortcuts, dative bonds for coordination chemistry, and SMILES export that keeps aromatic and ring bonds intact.

• ChemDraw keybinding scheme: an optional ChemDraw-compatible shortcut set with hover hotkeys (rings 3–0, wedge/hash sprouts, carbonyl, gem-dimethyl) and nickname labels (for example e over an atom applies Et). Switching schemes updates the main window, detached palettes, and menu accelerators live.
• Dative bonds: dashed bonds are now coordination (metal–ligand) bonds. They round-trip through MOL V3000, warn when saved as V2000, merge across molecules, and clean up through the layout engine.
• Atom labels: literal labels and naked typed atoms; Delete strips a label back to carbon before deleting the atom, and typed element symbols become real atoms whenever editing ends.
• Charge marks stack up to ±9, and Clear/Restore Warnings works on the current selection.
• SMILES export fixes: aromatic rings are kekulized instead of being written as saturated rings (benzene no longer exports as cyclohexane), a single ring keeps its ring-closure bond order (Kekulé benzene no longer exports as a cyclohexadiene), and bonds of unknown order are written with a warning.
• Structure-list export to SDF and SMILES in reading order.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

ChemDraft 0.3.3

Charge marks, electron-pushing mechanism arrows, and a Copy As menu for chemistry formats.

• Charge marks: anions and cations are now movable marks that associate with the nearest atom — place one from the charge dropdown and the atom takes the charge; drag the mark away and the atom reverts to its neutral valence instead of showing a stuck error. Marks ride along when their molecule is dragged, rotated, flipped, or scaled, so a repositioned structure keeps its chemistry.
• Mechanism arrows: ChemDraw-style electron-pushing arrows (full- and half-headed) that anchor to atoms or charge marks and gain one or two Bézier handles by length. They replace the old rotate-into-circle curved arrows.
• Symbol tools: charge, radical-dot, and lone-pair tools live behind one dropdown, matching the ChemDraw palette.
• Atom relabel: the text tool can relabel an existing atom — hover, click, type the element, then Enter or click off.
• Copy As: a new submenu in the Edit menu and the object right-click for SMILES, InChI, InChI Key, CDXML, MOL V2000/V3000, SVG, and PNG. PNG copies render at 4× with embedded 384 dpi density metadata, so they paste at the drawn size instead of oversized; SVG copies paste as real vector art in Illustrator instead of raw markup.
• Clipboard fixes: structure paste no longer corrupts the desktop clipboard, right-click no longer collapses a multi-object selection, and scoped copies keep their charges and mechanism arrows with unwarped arrow geometry.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

ChemDraft 0.3.2

The analyzers release: a property and prediction suite built around a new Molecular Inspector.

• Molecular Inspector: one real OS window for every analysis — open it from Analyze ▸ Molecular Inspector, with or without a selection. Reports carry full provenance: every number states its method and its inputs.
• pKa estimation: ionizable sites detected and scored by a graph neural network trained on measured pKa data, with a second independent method that is allowed to disagree. Values are drawn on the structure at the proton each one is about, each with a calibrated confidence interval, and acidic and basic sites are reported separately. Sites the method cannot honestly measure are withheld and say so.
• Protonation states: the inspector reports which species the molecule actually is at a given pH — which is what a pKa is a proxy for — including zwitterions and permanently charged species.
• Isotope envelopes: computed by IsoSpec and drawn as a spectrum on the m/z axis, not a table. Handles ions, adducts, neutral losses, and isotope-labelled structures, grouped under a new Mass Spec category.
• Name to structure: type an IUPAC name and get a structure, powered by a bundled OPSIN engine served across the plugin boundary (plugin API 0.1.1). The app says so honestly when a name cannot be parsed.
• Joback estimates: thermophysical property estimates (boiling point, critical properties, and more), each shown with its uncertainty rather than a bare number — and withheld for structures the method's groups cannot cover.
• Licensing: the app is now Apache-2.0, and bundled datasets declare their own terms.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).

ChemDraft 0.3.1

Fixes a stereochemistry-affecting import bug, plus a batch of toolbar and rendering fixes.

• Chirality fix: importing a real ChemDraw CDXML file could mirror wedge/hash stereochemistry, so an R stereocenter could render as S. Coordinate reading and writing now follow the CDXML spec order; ChemDraft-authored files still open exactly as before.
• Main toolbar style widget: adapts to the current selection (text, molecule, arrow, shape) with compact controls and a "More…" escape hatch to the full inspector.
• Arrow transform box: Shift-hover an arrow for rotate and 3D-tilt handles; resizing scales head, stroke, and shaft gap together as one undo.
• Rendering: eliminated stale "ghost" chrome pixels left behind by rotate/tilt handles and path-edit cages.
• Palettes: toolbars recover from off-screen positions, tooltips clamp to the correct monitor, and popovers no longer misplace on first open.
• Persistence: sessions, saved layouts, and arrow style defaults no longer get lost across restarts.
• A wide range of additional correctness and stability fixes from two independent code reviews, including formula/valence correctness, plugin storage reliability, and CDXML round-tripping.

Automatic updates are delivered via Sparkle (File ▸ Check for Updates…).