GitHub Copilot Adds Claude Opus 4.6 (Plus a New Fast Mode): What Changed and Who Gets Access

GitHub Copilot Adds Claude Opus 4.6 (Plus a New Fast Mode): What Changed and Who Gets Access

GitHub is expanding Copilot’s model roster again — this time with Claude Opus 4.6 and an experimental Fast mode variant aimed at developers who care about latency as much as quality.

If your team is standardizing on Copilot across editors (VS Code, Visual Studio, github.com, mobile, CLI), the practical question is simple: what’s available in which plan, and where do you enable it?

Primary sources:

• •GitHub Changelog — Claude Opus 4.6 generally available for Copilot (Feb 5, 2026):

https://github.blog/changelog/2026-02-05-claude-opus-4-6-is-now-generally-available-for-github-copilot/

• •GitHub Changelog — Fast mode for Claude Opus 4.6 (preview) (Feb 7, 2026):

https://github.blog/changelog/2026-02-07-claude-opus-4-6-fast-is-now-in-public-preview-for-github-copilot/

What GitHub announced (the non-hand-wavy list)

1) Claude Opus 4.6 is rolling out in Copilot

GitHub says Claude Opus 4.6 is “rolling out” in Copilot, and highlights early testing results focused on agentic coding, especially tasks that require planning and tool calling.

Who gets it: GitHub states Opus 4.6 will be available to Copilot Pro, Pro+, Business, and Enterprise users.

Where you can select it: GitHub lists:

• •Visual Studio Code (chat, ask, edit, agent)
• •Visual Studio (agent, ask)
• •github.com
• •GitHub Mobile (iOS/Android)
• •GitHub CLI
• •Copilot coding agent (Pro and Pro+ only)

Source: GitHub Changelog (Feb 5, 2026)

https://github.blog/changelog/2026-02-05-claude-opus-4-6-is-now-generally-available-for-github-copilot/

2) “Fast mode” for Opus 4.6 is in a research preview

GitHub also announced a Fast mode for Claude Opus 4.6, described as an “early and experimental” option that targets significantly faster inference.

GitHub’s stated claim: “up to 2.5x faster” output token speeds, while maintaining the “same intelligence as Opus 4.6.”

Who gets Fast mode: GitHub says Fast mode will be available to Copilot Pro+ and Enterprise.

Where you can select Fast mode: GitHub lists:

• •Visual Studio Code (all modes)
• •Copilot CLI

Source: GitHub Changelog (Feb 7, 2026)

https://github.blog/changelog/2026-02-07-claude-opus-4-6-fast-is-now-in-public-preview-for-github-copilot/

How to enable it (what admins should know)

GitHub’s changelog calls out a recurring gotcha: org plans often require policy toggles.

• •For Opus 4.6, GitHub says Copilot Business and Enterprise administrators must enable the Claude Opus 4.6 policy in Copilot settings.
• •For Fast mode, GitHub says Copilot Enterprise administrators must enable the Fast mode policy.

Sources:

• •Opus 4.6 enablement notes (Feb 5)

https://github.blog/changelog/2026-02-05-claude-opus-4-6-is-now-generally-available-for-github-copilot/

• •Fast mode enablement notes (Feb 7)

https://github.blog/changelog/2026-02-07-claude-opus-4-6-fast-is-now-in-public-preview-for-github-copilot/

When to pick Opus 4.6 vs Fast mode (practical guidance)

GitHub’s messaging makes a clear split:

• •Opus 4.6 (standard): for “hard tasks” that benefit from planning and tool calling.
• •Fast mode: for “significantly faster inference” when you want speed.

Here’s how that usually maps to real developer work:

Use Opus 4.6 (standard) when

• •you need multi-step refactors across a repo
• •you’re debugging with multiple hypotheses and want the model to stay organized
• •you’re doing code review / reasoning about edge cases
• •you want fewer “quick but wrong” suggestions

Use Fast mode when

• •you’re iterating on small edits or repetitive transforms
• •you’re exploring APIs (“generate a few options quickly”)
• •you’re in a tight loop and latency matters more than perfect answers

The important operational detail: because Fast mode is described as experimental, you should treat it like a performance beta — great for throughput, not a license to skip verification.

Guardrails teams should adopt (so speed doesn’t become risk)

Faster output changes behavior: it encourages devs to accept more suggestions per hour.

Three guardrails that pay for themselves:

1) Require tests for acceptance

• •If Copilot writes it, CI validates it.

2) Lock down secrets and production access

• •Keep the usual repo hygiene (secret scanning, least privilege).

3) Standardize the “prompt contract”

• •A short internal template (what you’re doing, constraints, expected output, what not to change) reduces churn and prevents accidental scope creep.

Bottom line

Claude Opus 4.6 in Copilot is a meaningful upgrade for teams doing agentic coding and longer reasoning-heavy tasks.

Fast mode is the more interesting signal: GitHub is explicitly optimizing for latency as a product feature, which usually means Copilot is moving from “assistant” toward “always-on pair programmer” — where speed directly affects adoption.

If you manage a team plan, check policies first. If you’re an individual dev, look for the model picker — rollout is gradual.