Frequently asked questions

How the product works

What is the goal of the ChemIllusion Project?

To help chemists, students, and product teams do real chemistry work faster — drawing, teaching, reviewing, and publishing — with AI used as a chemistry-validated assist, not a replacement for judgment.

Why do LLMs hallucinate chemistry, and how do we avoid it?

General-purpose models do not have enough chemistry in their training data, and token-level training methods handle chemical information poorly. ChemIllusion wraps the model layer with deterministic validation (SMILES, InChI, RDKit, structure rules) so suggestions that touch a molecule are checked before they reach the canvas. See this ACS article for background on failure modes, and this video for a summary.

How are hallucinations reduced in ChemIllusion?

Anything that defines a molecule is deterministic: SMILES and InChI parsing, RDKit-backed rendering, and structure validation. The AI layer handles description, teaching, and editing suggestions, and every structure it produces is validated against the deterministic layer before it appears on the canvas.

What parts of the workflow are deterministic vs. model-assisted?

Anything that touches molecular identity is deterministic: SMILES and InChI parsing, structure validation, RDKit-backed rendering, reaction-arrow checks, and export formatting. The AI layer is used for describing, teaching, routing work, and proposing edits — and every structure the AI surfaces is validated against the deterministic layer before it reaches the canvas. This is why ChemIllusion does not hallucinate molecules when general-purpose chat tools do.

What models are used?

For images we support Nano Banana 2 Lite (Gemini 3.1 Flash‑Lite Image, 1 AI Action), Nano Banana Pro (Gemini 3 Pro Image), Nano Banana 2.1 (Gemini Nano Banana 2.1), GPT‑Image‑2, GPT‑Image‑1.5 and GPT‑Image‑1 Mini, Gemini Imagen, FLUX 2 Max and FLUX 2 Pro, FLUX.1 Fill, Qwen Image Edit, and the DALL‑E 3 and DALL‑E 2 models. Paste Molecule Object and Paste Preview Structure flows are available for structure-driven edits. For chat and analysis we use GPT‑5.5, GPT‑4o, GPT‑4o‑mini, GPT‑o3, GPT‑5‑nano for quick passes, Gemini 3 Pro, Claude Opus 5.5, and Claude Sonnet 5.5. The NMR structure solver also uses Claude Opus 5.5 for structure proposals.

Are results guaranteed?

We cannot guarantee that an image will be free of chemical errors. Our tools are the best bet for getting images that are artistic and as accurate as possible.

What accessibility features does ChemIllusion offer for chemistry work?

ChemIllusion focuses on chemistry-specific access—not only generic image alt text. On the generator you can hear structure and toolbar names (Speak Molecule and optional hover audio), use a keyboard-friendly molecule panel with a readable structure tree and text-based edits, review descriptions for AI-generated images before sharing, enlarge toolbar icons, and use voice input where helpful. Sign-in and account screens were refreshed for clearer labels and keyboard use. We document conformance progress in our accessibility reports and explain the roadmap in our chemistry accessibility overview. See release notes for recent improvements.

Is the public ChemIllusion website available in languages other than English?

Key marketing pages — home, FAQ, pricing, About, drawing tools, and release notes — are localized in English, German, and Spanish with a locale switcher. The in-app generator experience is still primarily English.

Can I see what the projects page looks like before creating an account?

Yes — visit the projects page for an interactive preview. It shows example images, videos, canvas history, and assets so you can explore the full project workflow without signing up.

For teams and classrooms

Can ChemIllusion support classroom or department workflows?

Yes. Teachers can assemble a lesson track and share one link with a class from the free custom drawing lesson builder, or connect ChemIllusion inside an LMS when your campus enables it (see Can ChemIllusion launch inside my LMS?). Departments on Professional plans get approved-domain auto-join, bulk CSV onboarding, and audit log export. See recent admin features on the releases page for the latest controls.

Can ChemIllusion launch inside my LMS (Canvas, Brightspace, Blackboard, Moodle)?

Yes. When your school connects ChemIllusion through standard LMS integration, students and instructors open drawing tools and course-linked chemistry content from inside the LMS—without a separate ChemIllusion sign-in for each launch. The in-course home shows saved structures, opens a drawing workspace sized for LMS windows, links to the organic chemistry reader, and lets instructors open the full ChemIllusion site in a new tab for videos, tutorials, and advanced authoring. Opening the reader directly from the main site requires signing in with an authorized ChemIllusion account. Your IT or LMS administrator installs and configures the tool for your campus. See release notes for the latest LMS features.

Set up and launch ChemIllusion in Canvas LMS

Can teams control access to shared canvases and review flows?

Yes. Canvases can be shared via link, QR code, or team invite, and admins control who can view, comment, or edit. A built-in QR code generator makes it easy to hand out a canvas in class or at a poster session. Review mode preserves a read-only snapshot while letting reviewers leave comments without changing the artifact.

Teacher curriculum controls — how does teacherCurriculum work with the generator, and do lesson lists override drawingCoachLesson?

A class link adds teacherCurriculum with the curriculum share token. The generator loads the public manifest (the teacher’s selected Drawing Coach topic ids), and signed-in learners are enrolled in the background. After a successful load, ChemIllusion removes teacherCurriculum from the URL to keep links tidy while the selection keeps applying for that visit. Those topic ids narrow the Help Hub: lesson tracks and rows only list what the teacher picked, so the in-app lesson browser matches the assignment. That filter does not block a drawingCoachLesson deep link: if the topic id exists in the catalog, the requested lesson still opens and the Lesson Card behaves the same. Class progress updates only fire for topics that are part of the teacher’s selected list—completing a deep-linked lesson outside that list still updates the learner’s own help profile, but it is not rostered to that curriculum share. Build and copy links from the free custom drawing lesson builder.

Pricing and access

Do you offer free academic pricing?

Yes. Verified students, postdocs, and educators can enroll in our free academic pricing. Sign up with your institutional email, choose the Academic plan, and we will confirm eligibility.

How does pricing work?

You purchase a set amount of usage, and image generation is charged at fixed rates against that amount (12¢ for GPT‑Image‑1.5, 9¢ for FLUX 2 Max, 5¢ for Gemini-Flash-2.5, Gemini 3 Pro, FLUX 2 Pro, or DALL‑E image). The first few images are analyzed for chemical errors for free so you can see how the tool works, then cost 3¢ each. Image editing typically costs 5¢. Chat is priced based on token usage with different rates per model — GPT‑5.5 uses higher rates for premium quality, while GPT‑4o‑mini and GLM‑4.5 offer more affordable options. Every charge is itemized in the Projects page, and you can pre-approve overages or stay at the set limit for your tier.

Is this project open source?

Not currently. An open source version is planned in the future.

Drawing help and tutorials

How can I create images with accurate chemical structures?

Use structure-first workflows when you can: Paste Molecule Object or Paste Preview Structure so the layout comes from your drawn structure, then pick an image model that fits your scene. Keep molecule complexity reasonable. After generation, the analyze-image pass flags chemistry issues; soft or hard edits refine the result.

Where can I find step-by-step wrap instructions?

Follow the icon-only walkthrough for wrapping an adenosine structure onto a reagent bottle label using the Wrap tool. Read the full guide here: Adenosine reagent bottle guide.

Can I fix chemical errors with the edit tool?

The edit tool offers both soft and hard modes. Hard edits replace only the region you select to make corrections or changes and do not change the style. Soft edits remix the entire image to get the changes you request. For large fixes, it may still be easier and cheaper to start over.

What upload and download options are available?

You can import structures from SMILES, MOL, and ChemDraw CDX or CDXML files, then add them directly to the Ketcher-based editor. ChemDraw uploads generate PNG thumbnails you can download, and exported images stay ChemDraw-compatible while also offering PNG, SVG, PPTX, and Word (DOCX) downloads for quick placement in slides or manuscripts.

Export chemical structures as SVG, PNG, or Office files

Import SMILES, MOL, or ChemDraw files

How do I encode mechanism electron pushes in reaction SMILES?

Append electron pushes after a reaction using ||ep: notation, for example CCO.CN>>CCN.CO||ep:1|5|2;2-3|4|2. Supported tokens are start|end|electrons, start|end|electrons|offset, and a-b|end|electrons for pi-bond origins. When valid, ChemIllusion propagates this from SMILES input to canvas reaction metadata and renders curved electron-push arrows (with lone-pair origin markers when needed).

Draw curved arrows for a reaction mechanism

How can I draw chemical structures in Word?

Sketching structures using Word's built-in shapes is no fun. Draw your molecule in ChemIllusion's editor and paste the exported image directly into Word — our tool makes it easy to incorporate accurate structures without complex formatting.

Can I open the generator directly on a specific Drawing Coach lesson?

Yes. Add the drawingCoachLesson query parameter with a lesson topic id to the generator URL, for example this stereochemistry wedges lesson. The same topic ids power the Help Hub lesson list, including deep links from the home page lesson tiles.

Comparisons and alternatives

Could I do this with my own AI provider?

Of course — but it takes a lot of trial and error to get good results. Try ChemIllusion for a bit. The knowledge you gain here will make you better at prompting for chemical structures with any AI provider.

What free software can I use to draw molecules?

Popular free downloads include Avogadro, ACD/Labs ChemSketch, and ChemAxon MarvinSketch. ChemIllusion has a free browser-based drawing tool that we use as input for our AI generator to boost structural accuracy. You can also use JSME, the drawing tool in PubChem, or Ketcher.

Where can I find free chemistry images?

Icon libraries like The Noun Project, Flaticon, and Wikimedia Commons offer many chemistry graphics. ChemIllusion can generate custom images tailored to your needs, and every picture in our gallery is free to download and use.

Can I use images from ChemIllusion in journals?

You have the right to use the images you create here for your presentations, websites, and research publications (if they allow it). Journal policies on AI use are evolving. While these restrictions will not stand the test of time, don't submit something without checking the rules first. If you don't like the journal policies, let them know.