Which model should I use in Cursor: Composer 2, Sonnet 5, or Grok 4.5?

For pure multi-file edits and diff-heavy refactors: Cursor Composer 2 (61.7% Terminal-Bench 2.0, 73.7% SWE-bench Multilingual). For balanced coding + reasoning across mixed tasks: Claude Sonnet 5 ($2/$10 intro pricing, 1M context). For lowest cost per task at strong coding quality: Grok 4.5 ($2/$6, co-trained with Cursor data). Most Cursor power users route by task type.

What is Cursor Composer 2?

Cursor Composer 2 is Anysphere's proprietary coding model, released March 2026. It's specifically optimized for multi-file edits, precise diffs, and codebase-wide refactors in the Cursor IDE. Composer 2 scores 61.7% on Terminal-Bench 2.0 and 73.7% on SWE-bench Multilingual in Cursor's harness — outperforming Claude Opus 4.6 on some metrics at significantly lower cost.

Is Grok 4.5 better than Composer 2 in Cursor?

It depends on the task. Grok 4.5 (July 8, 2026) leads on general SWE benchmarks: 62.0% on DeepSWE 1.0, 83.3% on Terminal-Bench 2.1, 29.0% on SWE Marathon pass@1. Composer 2 was specifically tuned for Cursor's diff-application and multi-file edit patterns, so it can outperform Grok 4.5 on Cursor-native operations like precise refactors and applying deltas. Rule of thumb: Composer 2 for in-Cursor tight-loop edits, Grok 4.5 for broader agentic tasks.

How much does each model cost inside Cursor?

Cursor Composer 2 costs $0.10 per 100 tool calls (roughly $1-2 per hour of active coding for most users). Claude Sonnet 5 is billed at API rates through Cursor: $2 input / $10 output per MTok (intro pricing through Aug 31, 2026). Grok 4.5 is $2 input / $6 output per MTok. All three are available on Cursor's Pro ($20/mo), Pro+ ($60/mo), and Ultra ($200/mo) plans with different included usage.

Quick Answer

Cursor Composer 2 vs Claude Sonnet 5 vs Grok 4.5 in Cursor (July 2026)

Published: July 10, 2026

Three Models, One IDE

Cursor’s model picker in July 2026 offers three top-tier options for coding, and each has a different sweet spot:

Cursor Composer 2 — Anysphere’s own model, native to Cursor
Claude Sonnet 5 — Anthropic’s balanced flagship, June 30, 2026 launch
Grok 4.5 — SpaceXAI’s July 8, 2026 flagship, co-trained with Cursor coding traces

If you’re paying $20-$200/month for Cursor, picking the right model for the right task compounds into hours of productivity per week. Here’s the head-to-head.

Head-to-Head

Feature	Cursor Composer 2	Claude Sonnet 5	Grok 4.5
Provider	Anysphere	Anthropic	SpaceXAI
Released	March 2026	June 30, 2026	July 8, 2026
Context	~200K	1M	500K
Pricing	Metered (~$0.10/100 calls)	$2/$10 (intro)	$2/$6
Best for	Multi-file edits, diffs	Balanced coding + reasoning	Cost-efficient coding
Native to Cursor	✅	Third-party	Third-party (co-trained)
Terminal-Bench	61.7% (2.0)	~80% (2.1)	83.3% (2.1)
SWE-bench Multilingual	73.7%	~72%	~70%
SWE Marathon pass@1	~25%	~27%	29.0%

Where Each Wins

Cursor Composer 2 wins for:

Multi-file precise edits — the model was tuned for Cursor’s diff-application harness
Codebase-wide refactors — best at maintaining consistency across many files
Fast in-editor iteration — lowest latency of the three (native serving)
Cost predictability — flat metered pricing, not per-token
SWE-bench Multilingual — 73.7%, leads this specific benchmark

Claude Sonnet 5 wins for:

Long-context work — 1M-token default context is 2-5x the others
Balanced coding + reasoning — best when the task mixes code and analysis
Nuanced code review — reads and critiques code better than Composer 2 or Grok
Extended thinking — best step-by-step debugging for tricky bugs
Cursor’s default recommendation for most agent-mode tasks

Grok 4.5 wins for:

Cost efficiency — $6/MTok output is 40% cheaper than Sonnet 5
SWE Marathon / DeepSWE 1.0 — leads both, real long-horizon coding tasks
Terminal-Bench 2.1 (non-Ultra) — 83.3% beats Sonnet 5 for terminal work
Speed at scale — ~80 tok/s serving throughput
Cursor co-training advantage — model saw real developer trajectories

Practical Routing Strategy

Cursor power users increasingly do task-type routing in July 2026:

Task Type	Best Model
Apply a diff / precise edit	Composer 2
Refactor across 10+ files	Composer 2
Design + implement a new feature	Sonnet 5
Debug intermittent bug	Sonnet 5 (extended thinking)
Code review of PR	Sonnet 5
Long-horizon agentic task	Grok 4.5 or Sonnet 5
High-volume batch coding	Grok 4.5
Terminal-based work	Grok 4.5 or GPT-5.6 Sol Ultra
Long-context repo analysis (>500K)	Sonnet 5 (1M)
Codebase Q&A	Sonnet 5

You can encode this as Cursor Rules (.cursor/rules/) that hint at model selection per file pattern.

Pricing Reality Inside Cursor

Cursor Pro ($20/month) gives you:

Unlimited Composer 2 (metered per tool call)
500 fast requests to third-party models (Sonnet 5, Grok 4.5, GPT-5.6 Sol)
Unlimited slow-mode requests

Cursor Pro+ ($60/month):

1000 fast requests
Priority queue for Grok 4.5 and Sonnet 5

Cursor Ultra ($200/month):

5000+ fast requests
Priority access to GPT-5.6 Sol Ultra ($12.50/$75)

Rule of thumb: If you burn through 500 fast requests before mid-month, upgrade. If you barely touch them, downgrade to Free + BYOK.

Decision Framework

What's your priority?
│
├── Precise multi-file edits inside Cursor
│   → Composer 2 (native, optimized)
│
├── Balanced coding + reasoning
│   → Claude Sonnet 5
│
├── Cheapest per-task frontier coding
│   → Grok 4.5 ($6 output)
│
├── Long context (>500K tokens)
│   → Sonnet 5 (1M context)
│
├── Highest raw SWE benchmark score
│   → Grok 4.5 (SWE Marathon) or Sonnet 5
│
└── Latency-sensitive inline completions
    → Composer 2 (native serving)

What Changed Recently

July 8, 2026: Grok 4.5 launched, co-trained with Cursor coding traces
June 30, 2026: Claude Sonnet 5 went GA at $2/$10 intro pricing
June 2026: SpaceXAI (parent of xAI) acquired Cursor for a reported $60B
March 2026: Cursor Composer 2 released — 61.7% Terminal-Bench 2.0

The Bottom Line

For most Cursor users in July 2026, the winning pattern is:

Composer 2 for the tight in-editor edit loop (fast, cheap, tuned)
Sonnet 5 for planning, reasoning, and long-context reads
Grok 4.5 for high-volume batch work where cost matters more than nuance

If you can only pick one: Sonnet 5 for balanced work, Grok 4.5 if your monthly Cursor bill is your bottleneck.

Sources

Cursor Composer 2 Announcement — official Composer 2 blog
Grok 4.5 Launch (SpaceXAI) — official launch
Claude Sonnet 5 (Anthropic) — model page
Cursor Pricing — plan details