This model is not part of the weekly automatic sync. The figures below were confirmed on 2026-08-13.
GPT-5.3 Chat is an update to ChatGPT's most-used model that makes everyday conversations smoother, more useful, and more directly helpful. It delivers more accurate answers with better contextualization and significantly...
OpenAI: GPT-5.3 Chat — OpenAI. Context window 128,000 tokens. API pricing (per 1M tokens): Input $1.75, Output $14. License: Open-Weight. LMArena 1,389.
| Provider | OpenAI |
|---|---|
| API model ID | openai/gpt-5.3-chat |
| Tier | Mid |
| Context window | 128,000 tokens |
| Max output | 16,384 tokens |
| License | Open-Weight |
| API pricing (per 1M tokens) · Input | $1.75 |
| API pricing (per 1M tokens) · Output | $14 |
| LMArena | 1,389 (gpt-5.3-chat-latest) |
LMArena (CC-BY 4.0, best reasoning setting, 2026-10-02) · GPQA Diamond: Epoch AI (CC-BY 4.0)
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