GitHub Copilot: Fast Mode for Claude Opus 4.6
GitHub CopilotGitHub has launched a research preview of Fast mode for Claude Opus 4.6 in GitHub Copilot, delivering output token speeds up to 2.5x faster than standard Opus 4.6 while maintaining the same model intelligence. The feature is available to Copilot Pro+ and Enterprise users via the model picker in VS Code and the Copilot CLI. A 30x premium request multiplier applies after the promotional period, making Fast mode a performance tool best suited for latency-sensitive tasks.
Sources & Mentions
5 external resources covering this update
GitHub's official Fast mode announcement
X (Twitter)
Claude Opus 4.6 Just Got 2.5x Faster — Here's What Fast Mode Actually Means for Developers
Medium
Anthropic's Claude Fast Mode Delivers 2.5x Speed at 6x Price
Winbuzzer
Using Claude Opus 4.6 in Github Copilot
Microsoft Tech Community
Fast mode for Claude Opus 4.6 is now in preview for GitHub Copilot
daily.dev
Frontier Speed: Claude Opus 4.6 Gets a Fast Mode
GitHub has rolled out a research preview of Fast mode for Claude Opus 4.6, a performance-optimized configuration of Anthropic's flagship model that delivers substantially faster responses without sacrificing intelligence. The feature is available to Copilot Pro+ and Enterprise users, selectable via the model picker in Visual Studio Code across chat, ask, edit, and agent modes, and through the Copilot CLI.
The headline figure is a 2.5x increase in output token speeds — meaning responses and code generations arrive significantly faster than with standard Opus 4.6. GitHub and Anthropic are positioning this as "the same frontier intelligence, delivered at speed," targeting scenarios where latency materially impacts developer experience.
When Speed Matters
The practical case for Fast mode is strongest in interactive, latency-sensitive workflows: live debugging sessions where a slow response breaks developer flow, rapid iteration on code with frequent short exchanges, and agent mode tasks where each intermediate step involves waiting for a model response. For batch processing, long-running CI tasks, or situations where thoroughness matters more than speed, standard Opus 4.6 remains the appropriate choice.
Pricing and Premium Requests
Fast mode comes with a cost consideration. After a promotional period that ended February 16, 2026, a 30x premium request multiplier applies — meaning a single Fast mode call consumes 30 premium requests rather than the base rate. GitHub flagged this change prominently in the announcement, and it has already drawn attention from the developer community, with analysis noting that the speed gain comes at roughly 6x the API cost of standard Opus 4.6.
Enterprise plan administrators must enable the Fast mode policy in Copilot settings before their organization can access the feature.
Experimental Status
GitHub emphasized the research preview nature of this release, describing it as "early and experimental, focused on significantly faster inference." Users should expect the feature to evolve — pricing, availability tiers, and model behavior may change as the preview progresses.