Anthropic: Claude Opus 4.6 vs OpenAI: GPT-5.3-Codex
Side-by-side comparison of Anthropic: Claude Opus 4.6 and OpenAI: GPT-5.3-Codex. Compare pricing, context window, capabilities, and find out which is better for your workflow.
Verdict
moderate confidenceOpenAI: GPT-5.3-Codex leads overall
OpenAI: GPT-5.3-Codex has a meaningful edge overall, but Anthropic: Claude Opus 4.6 is stronger in specific areas. Your use case determines the right pick.
Best for with Anthropic: Claude Opus 4.6
Best for with OpenAI: GPT-5.3-Codex
Side-by-side
Technical specifications
| Anthropic: Claude Opus 4.6 | OpenAI: GPT-5.3-Codex | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input price | $5/M | $2/M |
| Output price | $25/M | $14/M |
| Context window | 1.0M | 400K |
| Max output | 128K | 128K |
| Capabilities | Tool useVisionReasoning | Tool useVisionReasoning |
| Released | Feb 4, 2026 | Feb 24, 2026 |
Scoring breakdown
How each dimension compares
Price
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.6
$5/M in / $25/M out
OpenAI: GPT-5.3-Codex
$2/M in / $14/M out
Context Window
Anthropic: Claude Opus 4.6 leadsAnthropic: Claude Opus 4.6
1.0M
OpenAI: GPT-5.3-Codex
400K
Capabilities
Anthropic: Claude Opus 4.6
3/4 features
OpenAI: GPT-5.3-Codex
3/4 features
Max Output
Anthropic: Claude Opus 4.6
128K
OpenAI: GPT-5.3-Codex
128K
Release Date
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.6
Feb 4, 2026
OpenAI: GPT-5.3-Codex
Feb 24, 2026
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