Model Comparison
Claude Sonnet 4.5GPT-5.3 Codex
Let's see who can write code better - Claude Sonnet 4.5 or GPT-5.3 Codex
Model Information
Claude Sonnet 4.5
Description
Balanced Claude 4.5 model with excellent performance
Specifications
Context Window200K
Max Output8K
ReleasedSep 2025
API✓
Pricing (per 1M)
In / Out
$3/ $15
Key Features
Balanced performanceAdvanced reasoningCode generationMulti-modal capabilities
Strengths
- ✓Good price-performance ratio
- ✓Versatile capabilities
- ✓Fast inference
- ✓Strong at most tasks
Weaknesses
- ✗Not as powerful as Opus
- ✗Higher cost than Haiku
- ✗May struggle with very complex tasks
Agent Support
No known agents
GPT-5.3 Codex
Description
Next-generation coding-optimized model from OpenAI with enhanced autonomous development capabilities
Specifications
Context Window272K
Max Output33K
ReleasedFeb 2026
API✓
Pricing (per 1M)
In / Out
$1.5/ $12
Key Features
Advanced autonomous codingEnhanced code reviewMulti-step reasoningFull-stack development
Strengths
- ✓State-of-the-art coding benchmarks
- ✓Superior autonomous task completion
- ✓Excellent code review capabilities
- ✓Large context window
Weaknesses
- ✗Premium pricing
- ✗Optimized for coding over general tasks
Agent Support
No known agents