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Model comparison Synced Apr 6, 2026

Anthropic: Claude Opus 4.5 vs OpenAI: GPT-5.1 Chat

Side-by-side comparison of Anthropic: Claude Opus 4.5 and OpenAI: GPT-5.1 Chat. Compare pricing, context window, capabilities, and find out which is better for your workflow.

Verdict

strong confidence

Anthropic: Claude Opus 4.5 leads overall

Anthropic: Claude Opus 4.5 leads in context window and capabilities and max output, making it the stronger choice for most workflows. OpenAI: GPT-5.1 Chat remains competitive with advantages in price.

Best for with Anthropic: Claude Opus 4.5

Long document processingMulti-modal tasksLong-form content generation

Best for with OpenAI: GPT-5.1 Chat

Budget-conscious workflows

Side-by-side

Technical specifications

Anthropic: Claude Opus 4.5 OpenAI: GPT-5.1 Chat
Provider Anthropic OpenAI
Input price $5/M $1/M
Output price $25/M $10/M
Context window 200K 128K
Max output 64K 16K
Capabilities
Tool useVisionReasoning
Tool useVision
Released Nov 24, 2025 Nov 13, 2025

Scoring breakdown

How each dimension compares

Price

OpenAI: GPT-5.1 Chat leads

Anthropic: Claude Opus 4.5

$25/M tokens

OpenAI: GPT-5.1 Chat

$10/M tokens

Context Window

Anthropic: Claude Opus 4.5 leads

Anthropic: Claude Opus 4.5

200K tokens

OpenAI: GPT-5.1 Chat

128K tokens

Capabilities

Anthropic: Claude Opus 4.5 leads

Anthropic: Claude Opus 4.5

3/4

OpenAI: GPT-5.1 Chat

2/4

Max Output

Anthropic: Claude Opus 4.5 leads

Anthropic: Claude Opus 4.5

64K tokens

OpenAI: GPT-5.1 Chat

16K tokens

Recency

Anthropic: Claude Opus 4.5

Nov 2025

OpenAI: GPT-5.1 Chat

Nov 2025

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