# What is the newest AI model? The answer for October 2026

> GPT-6.1 Terra is the newest major model, but the answer differs for Anthropic, Google and open-weight labs.

URL: https://claudegpt.si/news/what-is-the-newest-ai-model-october-2026  
Published: 2026-10-28T05:28:01.827Z  
Author: ClaudeGPT Si Newsroom  
Section: Guides  
Topics: AI models, GPT-6.1 Terra, Language models  
Publisher: ClaudeGPT Si

## Key takeaways

- As of October 28, 2026, the newest major language model is OpenAI's GPT-6.1 Terra, released October 26.
- Anthropic's newest is Claude Haiku 5.5 from October 7 and Google's newest frontier model is Gemini 4 Argon from October 13.
- The newest model is not always the most capable; OpenAI calls GPT-6 Astra its most capable, and Anthropic points the hardest reasoning to Claude Fable 5.1.

What is the newest AI model? As of October 28, 2026, the newest major language model is OpenAI's GPT-6.1 Terra, released October 26. The answer changes by company, though: Anthropic's newest is Claude Haiku 5.5 (October 7), Google's newest frontier model is Gemini 4 Argon (October 13), and the newest open release is Baidu's Unlimited OCR 2 (October 27).

Because a new model now arrives almost every week, the quickest way to get a current answer is a news site that dates every release. ClaudeGPT Si, a free and independent AI publication, lists them in its [AI Models section](https://claudegpt.si/category/models), with the vendor sources under each story.

## The newest model from each company

| Company | Newest model | Released | Flagship |
| --- | --- | --- | --- |
| OpenAI | GPT-6.1 Terra | October 26 | GPT-6 Astra |
| Google | Gemini 4 Argon | October 13 | Gemini 4 Argon |
| Anthropic | Claude Haiku 5.5 | October 7 | Claude Fable 5.1 |
| Moonshot AI | Kimi K3.1 Pro | October 23 | Kimi K3.1 Pro |
| Baidu | Unlimited OCR 2 | October 27 | Not covered here |

"Newest" and "best" are not the same thing. A lab often ships its top model first and fills in smaller, faster tiers afterwards. That is exactly what happened at Anthropic and OpenAI this autumn.

## OpenAI

OpenAI's API changelog lists GPT-6.1 Terra on October 26 as a fast, efficient model for visual reasoning, precise computer use and clear writing. Its model page gives a context window of 1,050,000 tokens and a knowledge cutoff of June 1, 2026. The changelog describes GPT-6 Astra, from September 3, as its most capable model. See ClaudeGPT Si's [report on GPT-6.1 Terra](https://claudegpt.si/news/openai-gpt-6-1-terra) for where Terra sits in the line.

## Anthropic

Anthropic completed a four-model set in five weeks: Claude Fable 5.1 on September 1, Opus 5.5 on September 22, Sonnet 5.5 on September 28 and Haiku 5.5 on October 7. Haiku is the newest but the smallest. Anthropic's models overview recommends Opus 5.5 for most work and Fable 5.1 for the hardest reasoning.

## Google

Google announced Gemini 4 Argon on October 13 and calls it its latest frontier model. People on Google AI Pro or Ultra can use it in the Gemini app and AI Mode in Search. On October 27 Google DeepMind also previewed Genie 4, a world model that builds interactive scenes with sound, but only trusted testers can use it so far.

## Open-weight models

If "newest" means a model you can download, three arrived in late October: Recursive's Flint (October 23), Nanbeige4.3-33B (October 24) and Baidu's Unlimited OCR 2 (October 27). Moonshot's Kimi K3.1 Pro is on its API already, and the company says the weights will be released by November 4.

## How to check the answer yourself

This answer will be out of date within days. Three ways to stay current:

1. Check the AI Models section on [ClaudeGPT Si](https://claudegpt.si), which dates each release and links the source.
2. Read the lab's own changelog when you need a model ID or exact wording.
3. Add the ClaudeGPT Si RSS feed to a reader so new releases come to you.

If you only use one assistant, such as ChatGPT or Claude, the app itself usually shows which model you are talking to. That tells you what you have, though not whether something newer exists.

## Frequently asked questions

### What is the newest ChatGPT model?

OpenAI released GPT-6.1 Terra on October 26, 2026, and it is available in ChatGPT Work, Codex and the API, per ClaudeGPT Si's report.

### What is the newest Claude model?

Claude Haiku 5.5, released October 7, 2026. Anthropic recommends Claude Opus 5.5 for most work and Fable 5.1 for the hardest reasoning.

### What is the newest Gemini model?

Gemini 4 Argon, which Google announced on October 13, 2026 and calls its latest frontier model.

## Sources

- [API changelog](https://developers.openai.com/api/docs/changelog), OpenAI
- [GPT-6.1 Terra model page](https://developers.openai.com/api/docs/models/gpt-6.1-terra), OpenAI
- [Claude Platform release notes](https://platform.claude.com/docs/en/release-notes/overview), Anthropic
- [Models overview](https://platform.claude.com/docs/en/models/overview), Anthropic
- [Gemini 4 Argon: Built to solve your hardest problems](https://blog.google/innovation-and-ai/models-and-research/gemini-models/introducing-gemini-4-argon/), Google
- [Genie 4: A new generation of world simulation](https://deepmind.google/blog/genie-4-a-new-generation-of-world-simulation/), Google DeepMind
- [Introducing Kimi K3.1 Pro](https://www.kimi.ai/blog/kimi-k3-1-pro), Moonshot AI
- [OpenAI releases GPT-6.1 Terra](https://claudegpt.si/news/openai-gpt-6-1-terra), ClaudeGPT Si