Sonnet 4.5 vs GPT-5.1

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

Winner
Anthropic

Claude Sonnet 4.5

4.8
Try Sonnet 4.5
OpenAI

GPT-5.1 Instant

4.7
Try GPT-5.1
Our Pick
Claude Sonnet 4.5

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

Try Sonnet 4.5

Feature Comparison

Feature
Sonnet 4.5
GPT-5.1
Ratings
Overall Rating
4.8
4.7
Coding
4.7
4.5
Writing
4.9
4.6
Reasoning
4.7
4.8
Speed
4.6
4.8
Value
4.9
4.6
Pricing
Monthly Price
$20
$20
Free Tier
Input (per 1M tokens)
$3
$2.5
Output (per 1M tokens)
$15
$10
Features
Context Window
200K
128K
Vision/Images
Audio
Video
Code Generation
AI Agents

Claude Sonnet 4.5

Pros

  • Best value for money
  • Excellent writing quality
  • Fast response times
  • Strong coding abilities
  • Free tier available

Cons

  • Not as powerful as Opus for complex tasks
  • Usage limits on free tier

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 Sonnet 4.5 if you need:

Daily coding tasks, writing, general use

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.