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OpenAIReleased 2026-04-23

GPT-5.6

OpenAI's flagship GPT model released April 23, 2026. The standard tier for GPT-5.6 family. $2.50/$15 per 1M input/output tokens. Strongest in complex multi-step reasoning, agentic workflows, and hard mathematics.

Context
1M tokens
Input
$2.5/1M
Output
$15/1M
Modalities
textimageaudiovideo

Best For

Complex reasoningAgent workflowsHard mathCode generation

Strengths

  • Best-in-class agent mode (multi-step task execution)
  • Strongest math and science reasoning
  • 1M token context window
  • Native multimodal: text + image + audio + video understanding
  • Function calling and tool use accuracy at 95%+

Weaknesses

  • Most expensive among top-tier models
  • Slower than Flash variants
  • Sometimes verbose; verbose tuning needed
  • Strict refusal behavior on borderline prompts

Related Alternatives

Claude Opus 4.8

Better for code and long-doc analysis

Gemini 3.5 Pro

Better Google Workspace integration

Kimi K3

Better for Chinese tasks, 5x cheaper

Frequently Asked Questions

How much does GPT-5.6 cost?

GPT-5.6 standard API costs $2.50 per 1M input tokens and $15 per 1M output tokens. The cheaper GPT-5.6 Luna variant costs $0.20/$1.20 per 1M (about 12x cheaper). ChatGPT Plus subscription at $20/month gives web access.

Is GPT-5.6 better than Claude Opus 4.8?

It depends on the task. GPT-5.6 wins for math, science, and multi-step agent workflows. Claude Opus 4.8 wins for code reasoning, long-form analysis, and nuanced writing. Most developers use both via API based on task type.

What is GPT-5.6's context window?

GPT-5.6 supports 1 million tokens of context, equivalent to ~750,000 words or 5-7 novels. It can process entire codebases or long documents without chunking.

See GPT-5.6's full record in our database

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