Claude Code UltraPlan: Cloud-Based Planning on Steroids

Claude Code's new UltraPlan feature moves the planning phase to the cloud, giving developers a faster and richer environment to review and refine their plans before a single line of code changes.

How It Works

UltraPlan operates in three stages:

Initiate from your terminal. You start inside a normal Claude Code session -- greenfield or brownfield project -- and tell it you want to use UltraPlan.
Plan in the cloud. Claude sets up a cloud session running in plan mode. This is plan mode on steroids: it runs Opus 4.6 in a remote container for up to 30 minutes, and your local terminal stays free for other work.
Review and execute locally. Once the plan is ready, you open it in your browser to review, comment, and edit. When you are happy with it, the plan comes back into Claude Code and you execute as normal.

The browser-based review interface lets you highlight specific passages, leave inline comments, and use emoji reactions to flag sections for revision. A structured outline sidebar helps navigate between sections of larger plans.

Planning Variants

Under the hood, UltraPlan runs multiple planning variants:

Variant	Description
Standard Plan	Default structured plan
Visual Plan	Includes Mermaid or ASCII diagrams for structural changes
Deep Plan	Uses subagents for risk assessments and architecture reviews

The variant is assigned dynamically -- you do not get to choose which one you receive.

Key Takeaways

UltraPlan offloads planning to the cloud, keeping your terminal free
It runs Opus 4.6 in a remote container for up to 30 minutes
Browser-based interface allows inline comments and structured review
Multiple planning variants (standard, visual, deep) are assigned automatically
Requires Claude Code v2.1.91+ and a Claude Code web account

Resources

UltraPlan Documentation -- Official Anthropic docs
Claude Code -- Anthropic's CLI coding agent