Phase 4 · Gemini · Level 2 · Practitioner
Canvas: a workspace for iterating
By the end, you'll be able to…
- Open Canvas and draft a document you can edit side by side with Gemini
- Iterate on a document with targeted changes instead of regenerating the whole thing
- Build a simple interactive app or page in Canvas and know its limits
Why it matters
Ordinary chat pushes each answer further up the screen, so a long document you're editing scrolls away. Canvas fixes that: your document or app sits in a panel beside the chat, and you refine it in place: change one section, keep the rest. It's the right tool whenever you're shaping something over several rounds, and it can even build a small working app from a plain description.
Why Canvas exists
Normal Gemini chat is a scroll: every reply lands below the last, so when you're working on a long document over several rounds, the version you care about keeps disappearing upward. Canvas solves that by opening a dedicated panel next to the conversation. Your document (or app, or page) lives in that panel; you talk to Gemini in the chat, and it edits the thing in the panel in place. Nothing scrolls away, and you can edit the panel directly yourself too.
Canvas is available in the Gemini app when you're signed in, and you turn it on from the controls beneath the prompt box before you send. It's one of the more accessible advanced features, though as ever the exact placement and what your account includes can vary; if you can't find it, that's an account matter, not a fault. Changes in Canvas auto-save, and you can export a document straight to Google Docs or slides to Google Slides.
We'll stay with Fernway, where you're Tom Elliott drafting a one-page proposal, the kind of document that always takes four or five passes to get right.
Iterating on a document
Start by asking for the document with Canvas on. Gemini drafts it into the side panel rather than the chat.
Draft a one-page proposal to offer Fernway's Harlow account an early-renewal discount. Audience: their operations manager. Sections: a short intro, what we're proposing (5% off if they renew before mid-August), why it's good for them, and a clear next step. Warm and professional, about 300 words.
Why this works: Naming the document type, audience, length and the sections you want gives Canvas a clear structure to build, so your first draft is already close to the shape you'll refine, not a blank page or a wall of prose.
Now the proposal sits in the panel. Instead of regenerating the whole thing when one part is off, you make targeted changes, the same iterate-don't-restart habit from Phase 0, but Gemini edits only the part you name and leaves the rest untouched.
Rewrite just the "why it's good for them" section to lead with the cost saving in actual pounds. The Pro Plan is £120, so 5% off across their renewal. Leave the rest of the document exactly as it is.
Why this works: A targeted instruction ('rewrite the second section', 'add a sentence') lets Canvas surgically edit one part while preserving everything you were happy with, far better than regenerating the whole document and losing the good bits.
You can keep going ("make the intro one sentence shorter", "add a line about our support response times", "change the tone to slightly more formal for a first approach") and each instruction edits the panel surgically. You can also click into the document and type your own edits directly; Canvas holds both your changes and Gemini's in the same live draft. When it's ready, export it to Google Docs to share or finish.
Building a simple app or page
Canvas isn't only for prose. From a plain-English description it can generate a simple interactive app, a web page or an infographic-style layout, show you a live preview in the panel, and let you refine it by asking, no coding required. This is impressive for quick internal tools and mock-ups.
Say Tom wants a rough calculator so the sales team can show customers their discount instantly.
Build a simple discount calculator: the user enters a plan price and a discount percentage, and it shows the amount saved and the final price. Keep it clean and easy to read, with our plan prices (£49, £120, £15) listed as a reminder. Show me a working preview.
Why this works: Describing the inputs, the calculation and the output in plain words is enough for Canvas to generate a working preview, so you get a usable prototype in one step and refine it by asking, without writing any code.
You'll get a live, clickable preview you can test and then refine: "make the saved amount bigger and green", "add a field for number of licences". It's a fast way to turn an idea into something people can actually click.
Be clear-eyed about the limits, though. Canvas builds quick prototypes and simple tools, not production software. What it makes is great for a mock-up, an internal one-off, or showing an idea, but it isn't tested, secured or maintained like real software, and you shouldn't treat a Canvas app as something to run your business on. It's a sketchpad that happens to produce working sketches.
Example prompts
Reorganise this document so the strongest benefit comes first and the pricing detail moves to the end. Keep my exact wording where you can. I only want the order and the headings changed.
Why this works: Asking Canvas to reorganise rather than rewrite preserves your wording while fixing the flow, so you keep the sentences you laboured over and only change their order and headings.
Take this proposal and give me a five-bullet email version I could send as a first, lighter approach: same offer, much shorter, friendly. Keep the full proposal in the Canvas as well so I still have both.
Why this works: Canvas can convert a finished draft into another shape (slides, a checklist, an email version) so you reuse the same content across formats instead of rewriting it, and can export each where it belongs.
On the discount calculator, add a dropdown to pick the plan (Starter, Pro, Add-on) that fills in the price automatically, and round the final price to two decimal places. Show me the updated preview.
Why this works: Plain-English tweaks ('add a field', 'change the colour') let you improve a prototype without touching code, the fastest way to iterate on a small tool, though you should still test each version yourself.
Try it now
Common mistakes
- Regenerating instead of editing. The point of Canvas is targeted change. Asking for the whole document again throws away edits you were happy with; name the section you want changed instead.
- Treating a Canvas app as real software. It builds prototypes, not production systems. A Canvas tool is fine for a mock-up or a one-off, but it isn't tested, secured or maintained, so don't run anything important on it.
- Over-trusting a polished draft. Canvas makes documents look finished fast, and a tidy proposal can still contain a wrong figure or an overclaim. Read every fact, especially prices and dates, before it leaves your hands.
- Forgetting it can see your direct edits too. If you type into the panel and then ask Gemini to change something, it works from the current combined draft. Keep track of who changed what so an instruction doesn't undo your manual edit.
- Assuming Canvas is on every account. Its availability and exact controls vary by account and plan. If you can't find it, that's an account matter, not a fault.
Keeping current
Canvas is developing quickly, and what it can build, how you turn it on, and the export options all change. Trust your screen over this lesson and check Google's official page, Create docs, apps and more with Canvas, and the Gemini Apps updates feed. Accurate as of 13 July 2026.