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GPT-5.3

OpenAI · GPT-5

Current GPT-5.3 Instant / Chat route for everyday ChatGPT work and API chat-style testing.

Part of GPT family · Other versions: GPT-5.5 Pro , GPT-5.5 , GPT-Rosalind , GPT-5.4 mini , GPT-5.4 nano , GPT-5.4-Pro , GPT-5.4 , GPT-5.3-Codex , GPT-5.2-Codex , GPT-5.2-Pro , GPT-5.2 , GPT-5-Codex , GPT-5 mini , GPT-5 , GPT-5 nano , GPT-4.1 , GPT-4o mini Transcribe , GPT-4o mini TTS , GPT-4o Transcribe , GPT-4o mini , GPT-4o
Type
language
Context
128K tokens
Max Output
16K tokens
Status
current
Input
$1.75/1M tok
Output
$14/1M tok
API Access
Yes
License
proprietary
reasoning everyday-work agentic tool-use coding cost-efficient
Released March 2026 · Updated March 27, 2026

Overview

Freshness note: Model capabilities, limits, and pricing can change quickly. This profile is a point-in-time snapshot last verified on March 27, 2026.

This page is best read as the GPT-5.3 Instant / GPT-5.3 Chat entry in OpenAI’s current lineup. OpenAI launched GPT-5.3 Instant on March 3, 2026 as the smoother, more useful everyday ChatGPT workhorse, and the API exposes that same route as gpt-5.3-chat-latest. OpenAI’s own docs now explicitly say they recommend GPT-5.2 for most direct API work, so GPT-5.3 is better understood as the latest conversational path rather than the main API flagship.

Capabilities

GPT-5.3 is designed for broad assistant work: drafting, coding, structured outputs, web-backed answers, and general professional workflows. OpenAI’s launch materials put special emphasis on better conversational flow, better judgment around refusals, more useful web-grounded answers, and fewer dead-end responses in everyday use.

Technical Details

OpenAI’s current GPT-5.3 Chat model card lists a 128K context window, 16,384 max output tokens, and the model ID gpt-5.3-chat-latest. That makes this route meaningfully narrower than GPT-5.2 or GPT-5.4 on raw context size, but much closer to the current ChatGPT experience.

Pricing & Access

Published API pricing for gpt-5.3-chat-latest (per 1M tokens):

  • Input: $1.75
  • Cached input: $0.175
  • Output: $14.00

OpenAI says GPT-5.3 Instant is available to all ChatGPT users and to developers in the API as gpt-5.3-chat-latest.

Best Use Cases

Use GPT-5.3 for day-to-day assistants, support chats, writing help, web-backed answers, and product experiences where you specifically want behavior close to current ChatGPT. For new agent-heavy API systems, OpenAI’s own docs point teams toward GPT-5.2 or GPT-5.4 first.

Comparisons

  • GPT-5.2 (OpenAI): Better starting point for most direct API builds and broader agent workflows.
  • GPT-5.4 (OpenAI): Better choice for harder professional reasoning and longer agent workflows.
  • Claude Sonnet 4.6 (Anthropic): Strong alternative when you want a broad production model outside OpenAI’s stack.