Best LLM for GitHub Copilot

Find the best AI model for GitHub Copilot based on coding performance, agent mode capability, and integration quality.

Prices on this page last verified September 7, 2026 against each provider’s own pricing page

GitHub Copilot has evolved from a GPT-only autocomplete tool into a multi-model platform with a model picker, agent mode, and workspace-aware features. Copilot offers frontier models from OpenAI (the GPT-5.5 generation and the code-focused GPT-5.3 Codex), Anthropic (Claude Sonnet 5 and the Claude Opus line), and Google (Gemini 3.1 Pro and Gemini 3 Flash) directly through its interface. OpenAI's GPT-5.6 family is now generally available on the OpenAI API, but Copilot exposes models on its own schedule and had not surfaced the 5.6 tiers in its picker when this page was last reviewed.

The recent story has been Anthropic's momentum. Claude Sonnet 5, launched June 30 with a 1M-token context window at $2/$10 per 1M tokens, has quickly become the community favorite for agent mode and multi-file refactors, scoring 85.2 on SWE-bench Verified. GPT models still enjoy a home-field advantage with tighter native integration, and GPT-5.5 remains the default flagship for many Copilot workflows. Our rankings reflect performance specifically within Copilot's ecosystem, including how well each model handles Copilot's prompt optimization, context management, and caching behind the scenes.

We ranked models based on GitHub documentation, community feedback, code completion quality, agent mode effectiveness, and how well each model handles Copilot's workspace-aware features. Pricing reflects the underlying API costs that inform Copilot's model allocation and usage limits.

Top Models for GitHub Copilot — September 2026

Claude Opus 5

Anthropic

Best OverallBoth suites · 92.5

In: $5/1M

Out: $25/1M

Ctx: 1.0M

Anthropic's flagship and the top scorer on SWE-bench Verified (96.0) among generally available models in this lineup. Opus 5 is the model to reach for when agent mode tackles the hardest debugging and architecture work, at $5/$25 with a full 1M context window — the same rate Opus 4.8 charges for an 88.6.

Claude Sonnet 5

Anthropic

Best valueBoth suites · 83.6Non-default tier

In: $2/1M

Out: $10/1M

Ctx: 1.0M

The strongest all-around pick in Copilot. Sonnet 5 pairs a 1M context window with an 85.2 SWE-bench Verified score at a standard $2/$10, which makes it even harder to beat for agent mode and multi-file refactors.

GPT-5.5

OpenAI

Longest contextTerminal-Bench only · 80.5

In: $5/1M

Out: $30/1M

Ctx: 1.1M

OpenAI's flagship in general availability and the model with the deepest native integration in the Copilot ecosystem. GPT-5.5 topped the Artificial Analysis Intelligence Index at its April launch and handles workspace-aware features with a 1M+ context window, though at $5/$30 it is the priciest mainstream option here.

Gemini 3 Flash

Google

Lowest priceNo published score

In: $0.5/1M

Out: $3/1M

Ctx: 1.0M

The most cost-effective model in this lineup with fast response times and a 1M context window at just $0.50/1M input. An excellent choice for developers who want to maximize their Copilot usage within subscription token limits on routine completions and quick edits.

Google's mainline option in Copilot with a 1M context window at $2/$12, undercutting both flagship tiers above it. Gemini 3.1 Pro is a sensible middle ground for developers who want strong general-purpose quality on large repositories without flagship pricing.

GPT-5.3 Codex

OpenAI

AA index only, no pass-rate score

In: $1.75/1M

Out: $14/1M

Ctx: 400K

Purpose-built for code generation with a 400K context window. GPT-5.3 Codex is tuned specifically for the kinds of completions and edits that Copilot handles, making it a strong pick for developers who want a code-specialized model at moderate pricing.

How We Ranked These Models

Order is computed, not hand-picked. Each model is scored on the published pass-rate suites it has (SWE-bench Verified 0.65, Terminal-Bench 2.1 0.35), renormalised over the suites present, then charged 1 quality point for every doubling of its blended price (3:1 input-to-output tokens). Models with no published score are never given one: they are listed after every scored model, ordered by context window, and labelled as unscored. Copilot's picker only offers OpenAI, Anthropic and Google models, so the field is restricted to those three. Completion and chat quality lead the weighting; API price presses only lightly — 1 point of pass rate per doubling — because a Copilot subscription, not the reader, pays the per-token bill. See the full ranking method.

Code Completion Quality

Accuracy and relevance of inline code suggestions, including how well the model predicts the developer's intent from partial code and surrounding context within Copilot's interface.

Agent Mode Effectiveness

How well the model performs in Copilot's agent mode for autonomous multi-step coding tasks, including file creation, editing, and terminal command execution.

Copilot Integration Depth

How deeply the model integrates with Copilot's features including workspace indexing, context management, caching optimizations, and model picker availability.

Underlying API Cost

The per-token API cost that influences Copilot's model allocation and usage limits. Lower-cost models may offer more generous usage within subscription tiers.

Frequently Asked Questions

What is the best model for GitHub Copilot in 2026?

Claude Sonnet 5 is our pick for best overall model in GitHub Copilot, combining a 1M context window, an 85.2 SWE-bench Verified score, and $2/$10 pricing that Anthropic has confirmed as standard. GPT-5.5 remains the strongest choice for developers who value the deepest native integration, and Claude Opus 5 leads on the hardest tasks.

Can I use Claude models in GitHub Copilot?

Yes. GitHub Copilot supports Anthropic models through its model picker, with Claude Sonnet 5 and the Claude Opus line as the current-generation options in Copilot Chat and agent mode. Claude models are particularly strong for multi-step autonomous coding tasks and complex refactors, and both offer 1M-token context windows for large repositories.

Which model is best for Copilot agent mode?

Claude Sonnet 5 is the community favorite for Copilot's agent mode thanks to strong instruction following and tool-use reliability at a reasonable $2/$10 price. Claude Opus 5 (96.0 SWE-bench Verified) is the step up for the most demanding autonomous tasks, while GPT-5.5 offers excellent agent performance with the advantage of deeper native integration.

Is Copilot worth it compared to using API keys directly?

For most developers, yes. Copilot provides optimized integration, context management, and caching that improve the raw model experience. Direct API access to a flagship like GPT-5.5 runs $5/1M input and $30/1M output, so heavy daily coding can add up quickly. The subscription is typically more convenient and cost-effective for everyday work.

What's the cheapest model I can use in Copilot?

Gemini 3 Flash at $0.50/1M input and $3/1M output is the cheapest option in this lineup, and it still carries a 1M context window. Gemini 3.1 Pro at $2/$12 is the next step up in quality. Choosing lower-cost models helps you stretch usage within Copilot's subscription token limits.

The same models, weighted for another tool

Each page states its own weighting, so the order changes with the workload.

Best for Coding Best for Claude Code Best for Cline Best for Kilo Code Best for OpenClaw Best for Hermes Agent Best for OpenCode Best for OpenHands Best for Cursor

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