Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war
Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war 22nd September 2026 Yesterday was Grok 4.7 (pelicans) and MiMo v2.6 Flash/Pro (more pelicans). Today Anthropic released Claude Opus 5.5, and around an hour later OpenAI released GPT-6 Sol and GPT-6 Luna. It’s going to take a while to get a good read on all of these new models, but here are my impressions so far.
- ▪Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war 22nd September 2026 Yesterday was Grok 4.7 (pelicans) and MiMo v2.6 Flash/Pro (more pelicans).
- ▪Today Anthropic released Claude Opus 5.5, and around an hour later OpenAI released GPT-6 Sol and GPT-6 Luna.
- ▪It’s going to take a while to get a good read on all of these new models, but here are my impressions so far.
2 outlets in our directory ran this story, first to last over 18 hours. All of the coverage we found sits in one bucket: centre. That one-sidedness is itself worth noticing.
Simon Willison files mainly under blogs. We currently carry 81 of its stories.
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Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | Simon Willison's Weblog |
| Canonical URL | https://simonwillison.net/2026/Sep/22/opus-and-sol-and-luna/ |
| Publication time | 2026-09-22T23:46:41+00:00 |
| Retrieval time | 2026-09-23T00:30:03.548Z |
| Last seen | 2026-09-23T00:30:03.548Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | zkYHzhSeCBwU · 3 stories |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war 22nd September 2026 Yesterday was Grok 4.7 (pelicans) and MiMo v2.6 Flash/Pro (more pelicans). Today Anthropic released Claude Opus 5.5, and around an hour later OpenAI released GPT-6 Sol and GPT-6 Luna. It’s going to take a while to get a good read on all of these new models, but here are my impressions so far. GPT-6 Sol and Luna are half the price of their GPT-5.6 equivalents GPT-5.6 Luna was already my favorite model for building applications against, because it combined excellent performance with being really cheap. Somehow GPT-6 Luna is half the price of that again—and GPT-6 Sol had a similar reduction compared to GPT-5.6 Sol.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at Simon Willison's Weblog.
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