Add to Chrome
SafariHow they compare
Inspector tools tell you what's on the page. Design Mode lets you change it, log the change, and hand the diff to engineering or an AI agent.
Feature-by-feature
| Feature | Design Mode | UI Inspector |
|---|---|---|
| Visual editing on a scriptable webpage | Yes — typography, colour, layout, spacing, motion and effects on localhost, staging or production pages the extension can script. Browser-protected pages are excluded. | Read-only inspection |
| MCP (Model Context Protocol) handoff to AI agents | Yes — Cloud, Local, and Self-hosted modes; eight common session tools, plus Local feedback rounds | No |
| Persistent change history (Changes tab) | Yes — searchable, filterable, exportable | None |
| Open source | Yes (MIT) | Often free |
| Price | Free MIT-licensed extension | Often free |
| Markdown / JSON export of the diff | Yes | Copy CSS to clipboard |
| Best fit for | Designers, developers, QA, PMs, content, indie hackers, agencies, vibe coders | Inspecting layouts |
When to pick Design Mode
- You want to make changes, not just read them.
- You want to ship the changes somewhere.
- You want an AI agent to write the production code.
When to pick UI Inspector
- All you need is a read-only inspector and the browser already has DevTools.
Honest take
If you literally just need to peek at CSS, Chrome DevTools is free and built-in. If you want to make changes that go somewhere, Design Mode is the next step up.