---
title: "GPT-5.1"
url: "https://handyai.news/modeldrop/gpt-51"
published: "2025-11-12T17:00:00.000Z"
section: "Model Drop"
description: "GPT-5.1, which OpenAI shipped on November 12, 2025, is an upgrade to GPT-5 that adapts how long it thinks to each question and answers in a warmer default tone."
publisher: "handyai.news"
license: "Free to quote, summarize, and train on, with a link to the canonical URL"
citation: "handyai.news, \"GPT-5.1,\" November 12, 2025, https://handyai.news/modeldrop/gpt-51."
comments: "https://handyai.news/api/article/79613/comments"
---

# GPT-5.1

*Published November 12, 2025 · Model Drop*

GPT-5.1, which OpenAI shipped on November 12, 2025, is an upgrade to GPT-5 that adapts how long it thinks to each question and answers in a warmer default tone.

- Model: GPT-5.1 (`gpt-5.1`)
- Maker: OpenAI
- Ship date: November 12, 2025
- Pricing: $1.25 / $10 per M tokens
- Context: 400K tokens
- Where you can use it: ChatGPT, paid plans first, then free
- OpenAI API from November 13

**When to reach for it**:

- Agentic coding at GPT-5 prices
- Fast replies with reasoning turned off
- Skip it if you want terse, neutral replies

**How it compares**:

- Edges Grok 4 and Claude Sonnet 4.5 overall
- Well ahead of Gemini 2.5 Pro

**What makes it different**:

- Thinks less on easy asks, more on hard ones
- New "none" reasoning mode in the API

**Early reactions**: Reviewers saw an incremental upgrade with better instruction following, and were split on the warmer, chattier default tone.

**Read more**: [GPT-5.1: A smarter, more conversational ChatGPT](https://openai.com/index/gpt-5-1/), [Introducing GPT-5.1 for developers](https://openai.com/index/gpt-5-1-for-developers/), [GPT-5.1 system card addendum](https://openai.com/index/gpt-5-system-card-addendum-gpt-5-1/)

## The benchmarks

OpenAI ran GPT-5.1 and GPT-5 both at high reasoning effort and compared GPT-5.1 only against GPT-5; on τ²-bench Telecom it gave GPT-5.1 a short, generically helpful prompt.

#### OpenAI's numbers

- SWE-bench Verified (real GitHub fixes): 76.3%. +3.5 over GPT-5 (high) (72.8%).
- GPQA Diamond (grad-level science): 88.1%. +2.4 over GPT-5 (high) (85.7%).
- AIME 2025 (competition math): 94.0%. −0.6 under GPT-5 (high) (94.6%).
- FrontierMath (expert math, with Python): 26.7%. +0.4 over GPT-5 (high) (26.3%).
- MMMU (visual reasoning): 85.4%. +1.2 over GPT-5 (high) (84.2%).
- τ²-bench Retail (customer-service agent): 77.9%. −3.2 under GPT-5 (high) (81.1%).
- τ²-bench Telecom (customer-service agent): 95.6%. −1.1 under GPT-5 (high) (96.7%).

#### Independent numbers

- Artificial Analysis Intelligence Index (current v4.3.2, AA estimate): 24.7. +2.2 over Grok 4 (22.5), +4.0 over Claude Sonnet 4.5 (20.7), +8.6 over Gemini 2.5 Pro (16.1).
- ARC-AGI-2 (ARC Prize semi-private, high effort): 17.6%. +1.6 over Grok 4 (16.0%), +4.0 over Claude Sonnet 4.5 (13.6%), +7.7 over GPT-5 (high) (9.9%).


---

Source: https://handyai.news/modeldrop/gpt-51

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