GPT-5.3 Chat
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 reduces unnecessary refusals, caveats, and overly cautious phrasing that can interrupt conversational flow.
Context window
This model accepts 128K tokens in one request (~96K words of text).
What fits in one request
- FitsShort documentAbout 1,500 words of text
- FitsLong documentAbout 37K words of text
- Won't fitSmall codebaseAbout 150K words of text
- Won't fitFull novelAbout 375K words of text
Specifications
Context size, pricing, and release info in one place.
- Context window
- 128,000 tokens (128K)
- Max output tokens
- 16,384 tokens (16K)
- Speed tier
- balanced
- Provider
- Openai
- Release date
- Mar 2026
- Input cost
- $1.75/M / 1M tokens
- Output cost
- $14.00/M / 1M tokens
- Cached input
- $0.175/M / 1M tokens
Capabilities
See which features this model supports, such as vision, tools, and streaming.
- Vision
- Accepts image inputs alongside text
- Supported
- Tool use
- Can call external tools and APIs
- Supported
- Function calling
- Structured function call interface
- Supported
- Extended thinking
- Shows its chain-of-thought reasoning
- Supported
- Streaming
- Returns tokens as they are generated
- Supported
- Prompt caching
- Reuse repeated prompt prefixes cheaply
- Supported
- Web search
- Can browse the web during a request
- Not supported
- Batch API
- Process many requests asynchronously
- Not supported
Best for
Jump to a guide or ranking that matches each workload.
Compare GPT-5.3 Chat
Open a side-by-side comparison with one click.
- GPT-5.3 Chat vs Amazon Titan Text Express
GPT-5.3 Chat has 204% larger context window
- GPT-5.3 Chat vs Amazon Titan Text Lite
GPT-5.3 Chat has 204% larger context window
- GPT-5.3 Chat vs Amazon Titan Text Premier
GPT-5.3 Chat has 204% larger context window
- GPT-5.3 Chat vs Claude Instant
GPT-5.3 Chat has 28% larger context window
- GPT-5.3 Chat vs Anthropic Claude
GPT-5.3 Chat has 28% larger context window
- GPT-5.3 Chat vs Codellama 34b Instruct
GPT-5.3 Chat has 3025% larger context window
Frequently asked questions
Short answers about context size and how this model behaves.
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