Calculator Tools vs ChatGPT Canvas

The short answer

Calculator Tools hosts a public static web app on your account. You get a calculator.tools URL, files you own, and a page anyone can open. ChatGPT Canvas is OpenAI's side-by-side editor in ChatGPT. You draft text or code and stay in the chat.

Use Canvas to write and revise inside ChatGPT. Publish here when you need a URL that is not the Canvas document. From ChatGPT, use an official custom GPT or MCP. From the browser, use Create.

What they do

Canvas sits next to the conversation. It is built for documents and code that you and the model pass back and forth. It is not branded as a public app host. It is a chat surface.

ChatGPT also has custom GPTs, file tools, and (when connected) MCP. Those are separate from Canvas. Canvas is the editor pane.

What Calculator Tools does

A hosted app is HTML, CSS, and JavaScript on your Calculator Tools account. Publish from Create, from an official custom GPT, or from MCP.

Files live in one directory. Typical files are index.html plus CSS, JavaScript, JSON, SVG, or similar static files.

Ownership stays with the account. Remix copies a public app on this site. Free accounts can publish 3 apps. Pro ($5.99/month) raises the limit to 25.

Calculator Tools does not provide ChatGPT's general chat, image generation, or Canvas editor.

Where they differ

Feature	ChatGPT Canvas	Calculator Tools
Primary job	Edit a doc or code in chat	Host a public static app
Account that holds the result	ChatGPT	Calculator Tools
Public `/app/` URL here	No	Yes
GPT Store assistant	Separate GPT feature	Official GPTs can publish here
Browse remixable apps	No	Browse

Canvas and Artifacts are different products. Canvas is ChatGPT. Artifacts is Claude. See Claude Artifacts and the Canvas definition. For a URL you own, publish on Calculator Tools.

When to use each

Use Calculator Tools when you want a shareable hosted calculator, tracker, or game on your account. Open Create.
Use a custom GPT or MCP when ChatGPT is already open and you want that assistant to publish here. See ChatGPT custom GPTs.
Use both. Draft logic in Canvas, then publish through a GPT or MCP for the hosted URL.
Use ChatGPT Canvas to revise an essay, a script, or a code file with ChatGPT in the loop. Canvas does not publish a calculator.tools URL.

Limits

Calculator Tools is not ChatGPT. It will not match Canvas for long-form writing.

A hosted app is a simple browser page. If you need a Next.js production frontend, look at v0. If you need a full-stack sandbox, look at Bolt. For a hosted static tool, use Calculator Tools.

Pro quota applies. Generated calculators can contain errors. Check the formulas.

Next step

Open Create, pick an official custom GPT, or connect MCP in ChatGPT. The first 3 apps are free.

Sources

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