Claude Opus 4.5 vs GPT-4o: Ultimate Flagship AI Model Comparison 2026

TLDR

Choose Claude Opus 4.5 if you need: Best-in-world coding (80.9% SWE-bench), autonomous agents, computer use automation, extended reasoning, larger context (200K tokens), and strongest prompt injection resistance.

Choose GPT-4o if you need: 2x lower cost ($2.50/$10 vs $5/$25), strong general performance across domains, established ecosystem, and proven reliability for production applications.

Budget: GPT-4o ($2.50/$10 per million tokens) is 2x cheaper than Claude Opus 4.5 ($5/$25 per million tokens).

Performance: Claude Opus 4.5 dominates coding, agents, and computer use. GPT-4o offers excellent general-purpose performance at a more accessible price point.

Overview

Claude Opus 4.5, released on November 24, 2025, represents Anthropic's most capable flagship model. It achieves the highest coding scores in the world (80.9% on SWE-bench Verified) and introduces extended thinking capabilities with a new effort parameter for controlling reasoning depth. Anthropic positions it as "the best model in the world for coding, agents, and computer use."

GPT-4o, released on May 13, 2024, is OpenAI's multimodal flagship designed for versatility and cost-efficiency. It balances strong performance across many domains while maintaining accessible pricing at $2.50/$10 per million tokens.

Both models represent peak AI capabilities from their respective companies, but they optimize for different priorities: Claude Opus 4.5 for maximum capability, GPT-4o for cost-effective versatility.

Basics: Model Specifications

Pricing: Cost Comparison

For a typical task using 50,000 input tokens and generating 5,000 output tokens:

• Claude Opus 4.5: $0.375 per request
• GPT-4o: $0.175 per request

GPT-4o's 2x cost advantage makes it more accessible for high-volume production applications.

Note: Claude Opus 4.5 offers up to 90% cost savings with prompt caching and 50% savings with batch processing, which can significantly reduce costs for repeated operations.

Performance: Benchmark Comparison

Coding Performance

Claude Opus 4.5 achieves the highest SWE-bench Verified score of any model in the world at 80.9%, making it the definitive leader for real-world software engineering tasks.

Computer Use & Agentic Tasks

Claude Opus 4.5's 66.3% score on OSWorld demonstrates superior autonomous computer use capabilities. GPT-4o doesn't specialize in computer use tasks.

General Knowledge & Reasoning

GPT-4o demonstrates strong general knowledge and mathematical reasoning capabilities. Claude Opus 4.5's exact scores aren't publicly disclosed, but it's optimized for coding and agentic tasks rather than general knowledge.

Intelligence Index

Claude Opus 4.5 scores 70 on the Artificial Analysis Intelligence Index in reasoning mode and 60 in non-reasoning mode, with 43% accuracy and the 4th-lowest hallucination rate at 58%.

Extended Thinking: Claude Opus 4.5's Unique Feature

Claude Opus 4.5 introduces extended thinking with an effort parameter that lets you control reasoning depth:

• Low effort: Faster responses with standard reasoning
• Medium effort: Balanced thinking for most tasks
• High effort: Deep reasoning for complex problems

This gives you control over the cost-performance tradeoff for each request. GPT-4o doesn't offer configurable reasoning effort.

Memory Tool: Beyond Context Windows

Claude Opus 4.5 includes a Memory Tool (beta) that lets the model store and retrieve information beyond the 200K context window. This enables:

• Long-term context: Remember information across sessions
• Persistent knowledge: Build up domain expertise over time
• Contextual recall: Access relevant information without re-sending

GPT-4o relies solely on its 128K context window without persistent memory.

Prompt Injection Resistance

Claude Opus 4.5 is described as "the most robustly aligned model with best prompt injection resistance of any frontier model." This makes it more secure for:

• Production applications: Resistant to adversarial inputs
• User-facing systems: Safer handling of untrusted prompts
• Enterprise deployments: Better security guarantees

GPT-4o has standard safety measures but isn't specifically highlighted for prompt injection resistance.

Context & Output Capacity

Claude Opus 4.5's larger context window and 4x larger output capacity make it better suited for:

• Processing long documents
• Generating comprehensive reports
• Multi-turn conversations with extensive history

Modality Support

Claude Opus 4.5:

• Text ✓
• Vision ✓
• Audio ✗
• Video ✗

GPT-4o:

• Text ✓
• Vision ✓
• Audio ✓
• Video ✗

GPT-4o's audio support gives it an edge for voice applications and audio transcription tasks.

When to Use Each Model

Use Claude Opus 4.5 when you need:

• Best coding performance: Highest SWE-bench score (80.9%) in the world
• Autonomous agents: Superior computer use capabilities (66.3% OSWorld)
• Extended reasoning: Configurable thinking depth with effort parameter
• Larger context: 200K tokens vs 128K for longer documents
• Long outputs: 64K max output vs 16K for comprehensive generation
• Security: Best prompt injection resistance for production safety
• Memory: Persistent information storage beyond context window
• Latest knowledge: March 2025 cutoff vs October 2023

Use GPT-4o when you need:

• Cost efficiency: 2x cheaper for high-volume applications
• Audio capabilities: Native audio input and output support
• General versatility: Strong performance across many domains
• Proven reliability: Longer track record in production (since May 2024)
• Ecosystem: Extensive tooling and integration support
• Math and reasoning: Strong MATH benchmark performance (76.6%)

Availability & Platforms

Claude Opus 4.5:

• Anthropic API
• Amazon Bedrock
• Google Cloud Vertex AI
• Microsoft Azure

GPT-4o:

• OpenAI API
• Microsoft Azure OpenAI Service
• ChatGPT Plus and Team plans

Both models are widely available across major cloud platforms.

Orchestrate Claude Opus 4.5 and GPT-4o with Miniloop

The choice between Claude Opus 4.5 and GPT-4o doesn't have to be binary. Claude excels at coding and agents, while GPT-4o offers cost-effective general performance.

With Miniloop, you can build AI workflows that use both models strategically. Route complex coding tasks to Claude Opus 4.5's world-leading SWE-bench performance, then use GPT-4o for general text processing at 2x lower cost. Or leverage Claude's extended thinking for hard problems while using GPT-4o for routine operations.

Miniloop lets you:

• Combine flagship models from different providers in one workflow
• Route coding and agentic tasks to Claude Opus 4.5
• Use GPT-4o for cost-sensitive operations
• Switch between models based on task complexity and budget
• A/B test flagship models to optimize performance and cost
• Build hybrid pipelines that leverage each model's unique strengths

Stop overpaying for capabilities you don't always need. Start building multi-model flagship workflows with Miniloop.

Get Started with Miniloop →

Sources

• Claude Opus 4.5 Benchmarks and Analysis - Artificial Analysis
• Introducing Claude Opus 4.5 - Anthropic
• Claude Opus 4.5 Specs - LLM Stats
• GPT-4o Model Specs - Galaxy.ai
• GPT-4o Benchmarks