ZeroHour

Source: Simon Willison

5 stories in the last 30d

Gemini Live audio

Google released Gemini 3.8 Live speech-to-speech models; Simon Willison built a library-free browser web UI for real-time voice conversations with them.

Google released Gemini 3.8 Live and Gemini 3.8 Live Extended Thinking, two new speech-to-speech models comparable in shape to OpenAI's GPT-Live family. Simon Willison had GPT-6 Astra Extra High build him a web UI for testing the models, supporting model and voice preset selection, optional system prompts, and interrupting the model mid-speech. The implementation uses no libraries and talks directly to Google's wss://generativelanguage.googleapis.com BidiGenerateContent WebSocket endpoint.

Simon Willison · 21h agoModel release

Introducing ChatGPT Images 2.5

OpenAI launches ChatGPT Images 2.5 with two API variants improving multi-turn instruction following and subject-preserving edits.

OpenAI released ChatGPT Images 2.5, exposing two API model IDs: gpt-image-2.5-sunburst for precision editing and gpt-image-2.5-flare for fast everyday generation. The company says its image models have generated more than 3 billion images across ChatGPT Images and the GPT-Image API. The update improves multi-turn instruction following, response speed, and preservation of subjects from reference photos.

Simon Willison · 7d agoModel release

Introducing GPT-6 Astra for developers

OpenAI introduces GPT-6 Astra for developers, with improved attention to detail, prompt understanding, and notably strong 3D model generation.

Simon Willison shares early hands-on impressions of OpenAI's GPT-6 Astra developer release, noting across-the-board improvements in attention to detail and prompt understanding. The model reportedly excels at building 3D models, producing renderings of gardens, shipyards, animals, cityscapes, and Dyson spheres. The write-up is third-party testing rather than an official announcement.

Simon Willison · 10d agoModel release1

GPT‑6 Astra

OpenAI launches GPT-6 Astra, a frontier model scoring 99.9% on ARC-AGI 3, priced $10/$50 per million tokens, rolling out to ChatGPT and API.

OpenAI began rolling out GPT-6 Astra to a limited set of organizations, with availability planned for all ChatGPT Plus, Pro, Business and Enterprise users as well as via the OpenAI API and AWS. API pricing matches Anthropic's Claude Fable 5 and 5.1 at $10 per million input tokens and $50 per million output tokens. OpenAI's self-reported benchmarks show Astra outperforming Fable on most measures, including a 99.9% score on the ARC-AGI 3 benchmark released in March.

Simon Willison · 12d agoModel release1

Claude Fable 5.1 made me a really nice animated pelican

Anthropic launched Claude Fable 5.1, claiming gains in coding and long-running tasks, with 52.6% on Terminal-Bench-Science 0.1.

Anthropic released Claude Fable 5.1 (alongside Mythos 5.1), positioning it as a new standard for coding, knowledge work, and long-running problem-solving. The model scores 52.6% on Terminal-Bench-Science 0.1, up from 24.7% for Fable 5, versus 29.0% for Opus 5 and 22.4% for GPT-5.6 Sol. Simon Willison's hands-on test found the model produced an impressive animated pelican, though he notes other benchmarks show only slightly improved scores.

Simon Willison · 14d agoModel release1