Anthropic: Claude Opus 4.5 vs OpenAI: GPT-5.3-Codex
Side-by-side comparison of Anthropic: Claude Opus 4.5 and OpenAI: GPT-5.3-Codex. Compare pricing, context window, capabilities, and find out which is better for your workflow.
Verdict
strong confidenceOpenAI: GPT-5.3-Codex leads overall
OpenAI: GPT-5.3-Codex leads clearly, winning on 4 of 5 dimensions. Choose OpenAI: GPT-5.3-Codex unless your workflow specifically requires Anthropic: Claude Opus 4.5's advantages.
Best for with Anthropic: Claude Opus 4.5
Best for with OpenAI: GPT-5.3-Codex
Side-by-side
Technical specifications
| Anthropic: Claude Opus 4.5 | OpenAI: GPT-5.3-Codex | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input price | $5/M | $2/M |
| Output price | $25/M | $14/M |
| Context window | 200K | 400K |
| Max output | 64K | 128K |
| Capabilities | Tool useVisionReasoning | Tool useVisionReasoning |
| Released | Nov 24, 2025 | Feb 24, 2026 |
Scoring breakdown
How each dimension compares
Price
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.5
$5/M in / $25/M out
OpenAI: GPT-5.3-Codex
$2/M in / $14/M out
Context Window
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.5
200K
OpenAI: GPT-5.3-Codex
400K
Capabilities
Anthropic: Claude Opus 4.5
3/4 features
OpenAI: GPT-5.3-Codex
3/4 features
Max Output
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.5
64K
OpenAI: GPT-5.3-Codex
128K
Release Date
OpenAI: GPT-5.3-Codex leadsAnthropic: Claude Opus 4.5
Nov 24, 2025
OpenAI: GPT-5.3-Codex
Feb 24, 2026
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