Opus 4.5 vs GPT-5.1

A detailed comparison to help you choose the right AI tool for your needs.

Winner
Anthropic

Claude Opus 4.5

4.9
Try Opus 4.5
OpenAI

GPT-5.1 Instant

4.7
Try GPT-5.1
Our Pick
Claude Opus 4.5

Claude Opus 4.5 edges out GPT-5.1 Instant with superior overall performance and features that make it the better choice for most users.

Try Opus 4.5

Feature Comparison

Feature
Opus 4.5
GPT-5.1
Ratings
Overall Rating
4.9
4.7
Coding
5.0
4.5
Writing
4.8
4.6
Reasoning
4.9
4.8
Speed
4.2
4.8
Value
4.5
4.6
Pricing
Monthly Price
$20
$20
Free Tier
Input (per 1M tokens)
$5
$2.5
Output (per 1M tokens)
$25
$10
Features
Context Window
200K
128K
Vision/Images
Audio
Video
Code Generation
AI Agents

Claude Opus 4.5

Pros

  • Best coding model available (80.9% SWE-bench)
  • Excellent for autonomous agents
  • Effort parameter allows speed/quality tradeoff
  • 76% fewer tokens than Sonnet at same quality
  • Strong at long-horizon tasks

Cons

  • More expensive than Sonnet
  • Slower on simple tasks
  • Requires Claude Pro/Max subscription for full access

GPT-5.1 Instant

Pros

  • Fast responses with adaptive reasoning
  • New personalization presets
  • Strong math and coding improvements
  • Multimodal (text, image, audio)
  • Free tier available

Cons

  • Coding not as strong as Claude Opus
  • Can be verbose
  • Writing style less natural than Claude

Choose Opus 4.5 if you need:

Professional developers, complex codebases, autonomous agents

Choose GPT-5.1 if you need:

General assistant, math problems, quick coding help

Ready to get started?

Both tools offer free tiers or trials. Try them out and see which one works best for your workflow.