Key Takeaways
Claude Opus 4.6 wins:
- Larger context window
GPT-5.3 Codex wins:
- Cheaper input tokens
- Cheaper output tokens
- Faster response time
- Higher intelligence benchmark
- Better at coding
Price Advantage
GPT-5.3 Codex
Benchmark Advantage
GPT-5.3 Codex
Context Window
Claude Opus 4.6
Speed
GPT-5.3 Codex
Pricing Comparison
Price Comparison
| Metric | Claude Opus 4.6 | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $5.00 | $1.75 | GPT-5.3 Codex |
| Output (per 1M tokens) | $25.00 | $14.00 | GPT-5.3 Codex |
| Cache Read (per 1M) | $0.50 | $0.17 | GPT-5.3 Codex |
| Cache Write (per 1M) | $6.25 | N/A | Claude Opus 4.6 |
Using a 3:1 input/output ratio, GPT-5.3 Codex is 52% cheaper overall.
Claude Opus 4.6 Providers
No provider data available
GPT-5.3 Codex Providers
No provider data available
Benchmark Comparison
3
Benchmarks Compared
0
Claude Opus 4.6 Wins
3
GPT-5.3 Codex Wins
Benchmark Scores
| Benchmark | Claude Opus 4.6 | GPT-5.3 Codex | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 46.5 | 54.0 | |
Coding Index Code generation & understanding | 47.6 | 53.1 | |
GPQA Graduate-level science | 84.0 | 91.5 |
GPT-5.3 Codex significantly outperforms in coding benchmarks.
Cost vs Quality
X-axis:
Y-axis:
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Other models
Context & Performance
Context Window
Claude Opus 4.6
1,000,000
tokens
GPT-5.3 Codex
400,000
tokens
Claude Opus 4.6 has a 60% larger context window.
Speed Performance
| Metric | Claude Opus 4.6 | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Tokens/second | 48.1 tok/s | 68.4 tok/s | |
| Time to First Token | 1.68s | 87.36s |
GPT-5.3 Codex responds 42% faster on average.
Capabilities
Feature Comparison
| Feature | Claude Opus 4.6 | GPT-5.3 Codex |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | Claude Opus 4.6 | GPT-5.3 Codex |
|---|---|---|
| License | Proprietary | Proprietary |
| Author | Anthropic | OpenAI |
| Released | Feb 2026 | Feb 2026 |
Claude Opus 4.6 Modalities
Input
textimage
Output
text
GPT-5.3 Codex Modalities
Input
textimage
Output
text