Anthropic: Claude Opus 4.5 vs OpenAI: GPT-5.3 Chat
Side-by-side comparison of Anthropic: Claude Opus 4.5 and OpenAI: GPT-5.3 Chat. Compare pricing, context window, capabilities, and find out which is better for your workflow.
Verdict
strong confidenceAnthropic: Claude Opus 4.5 leads overall
Anthropic: Claude Opus 4.5 leads clearly, winning on 3 of 5 dimensions. Choose Anthropic: Claude Opus 4.5 unless your workflow specifically requires OpenAI: GPT-5.3 Chat's advantages.
Best for with Anthropic: Claude Opus 4.5
Best for with OpenAI: GPT-5.3 Chat
Side-by-side
Technical specifications
| Anthropic: Claude Opus 4.5 | OpenAI: GPT-5.3 Chat | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input price | $5/M | $2/M |
| Output price | $25/M | $14/M |
| Context window | 200K | 128K |
| Max output | 64K | 16K |
| Capabilities | Tool useVisionReasoning | Tool useVision |
| Released | Nov 24, 2025 | Mar 3, 2026 |
Scoring breakdown
How each dimension compares
Price
OpenAI: GPT-5.3 Chat leadsAnthropic: Claude Opus 4.5
$5/M in / $25/M out
OpenAI: GPT-5.3 Chat
$2/M in / $14/M out
Context Window
Anthropic: Claude Opus 4.5 leadsAnthropic: Claude Opus 4.5
200K
OpenAI: GPT-5.3 Chat
128K
Capabilities
Anthropic: Claude Opus 4.5 leadsAnthropic: Claude Opus 4.5
3/4 features
OpenAI: GPT-5.3 Chat
2/4 features
Max Output
Anthropic: Claude Opus 4.5 leadsAnthropic: Claude Opus 4.5
64K
OpenAI: GPT-5.3 Chat
16K
Release Date
OpenAI: GPT-5.3 Chat leadsAnthropic: Claude Opus 4.5
Nov 24, 2025
OpenAI: GPT-5.3 Chat
Mar 3, 2026
Related comparisons
Anthropic: Claude Opus 4.5 vs OpenAI: GPT-5.4 Pro
flagship tier · Cross-provider
Anthropic: Claude Opus 4.5 vs OpenAI: GPT-5.4
flagship tier · Cross-provider
Google: Gemini 3.1 Pro Preview Custom Tools vs OpenAI: GPT-5.3 Chat
flagship tier · Cross-provider
Google: Gemini 3.1 Pro Preview vs OpenAI: GPT-5.3 Chat
flagship tier · Cross-provider