Claude Opus 4.8 (Fast) vs GPT-5.3-Codex
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Claude Opus 4.8 (Fast) vs GPT-5.3-Codex: side by side
| Spec | Claude Opus 4.8 (Fast) | GPT-5.3-Codex | Winner |
|---|---|---|---|
| Intelligence | 61.4 | 53.6 | Claude Opus 4.8 (Fast) |
| Output speed | 62 t/s | 101 t/s | GPT-5.3-Codex |
| Output price | $50.00/1M | $14.00/1M | GPT-5.3-Codex |
| Context | 1000K | 400K | Claude Opus 4.8 (Fast) |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Anthropic | OpenAI | Tie |
Claude Opus 4.8 (Fast)
Pros
- +Strong safety alignment
- +Nuanced and careful reasoning
- +Effective large-context handling
- +High-quality writing and analysis
Cons
- –Can be overly cautious on edge cases
- –Multimodal performance varies with image clarity
- –Fast mode may trade some depth for speed
GPT-5.3-Codex
Pros
- +Specialized for programming workflows
- +Extensive context handling
- +Support for diverse input types
Cons
- –Narrower focus than general-purpose models
- –Performance tied to input quality
Frequently asked questions
It depends on your needs. Claude Opus 4.8 (Fast) and GPT-5.3-Codex are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.