Chat is the primary way to steer Claude Design. You're not prompting once and done, you're having a design review, in writing, with an AI that can make changes in seconds. The patterns that work in a real design critique work here too.
Here's an iteration pass on Lineup, the kanban board from Lesson 2. One message, "add a left sidebar with project navigation", and Claude reads the existing canvas, builds the sidebar, and drops it in without disturbing the column layout. It then tells you what it added and which choices it made for you.
What chat is best for
- Broad changes: 'Make the color scheme warmer' or 'Swap the hero and pricing sections'
- Structural moves: 'Add a testimonial block between features and footer'
- Alternative directions: 'Show me three layouts for the hero, centered, split, and full-bleed'
- Content-level edits: 'Rewrite the headline to emphasize speed instead of accuracy'
What chat is slower for
- Changing one specific element (use inline comments, next lesson)
- Micro-adjustments to spacing or color values (direct canvas edits)
- Producing variations (use Tweaks, Lesson 6)
How to structure iteration messages
State what's working
Tell Claude what to keep. 'The hero layout is right; keep the three-column feature grid.' This prevents Claude from re-doing things you liked.
State what's not working
Be specific. 'The pricing cards feel cramped, too much text per card.' Much better than 'pricing looks bad.'
State what to change it to
Give direction, not just a problem. 'Reduce pricing cards to three bullet points each and use a lighter-weight body font.'
Claude Design puts a Model selector right in the prompt bar. You choose which Claude model does the work, such as Sonnet 5.5 or the more capable Opus 5.5 at the time of writing, and you can set an Effort level too. Sonnet is the sweet spot for most design work; reach for Opus on complex, detail-heavy builds. Whichever you pick reasons about your current canvas while processing your message, so references like 'the second feature card' work without extra context.
Claude Design has no version history yet, so a big change can't be undone. Before you ask for something very different, say "Save what we have and try a completely different approach." Claude keeps the current version and starts the new one alongside it.
You can iterate via chat
- Know what to ask chat vs. other tools
- Can frame changes with keep-fix-direction
- Know that references like "the second card" work, because Claude reads your canvas
Next: targeting specific canvas elements with inline comments.