TL;DR
A rumor that Anthropic may soon release Claude Opus 4.8 and Sonnet 4.8 rests on a March code leak and a thinly traded Polymarket ladder. The 70% market figure being cited appears to apply to June 15, while May 31 is listed around 26%.
A developer rumor that Anthropic is close to releasing Claude Opus 4.8 and Claude Sonnet 4.8 is being driven by a real Polymarket odds ladder and a March code leak, but the most-cited claim about a 70% chance by May 31 is not supported by the supplied market data.
The source material says Anthropic has not announced Claude 4.8, published an API model ID, released a model card, or shared benchmarks for Opus 4.8 or Sonnet 4.8. The confirmed product lineup cited in the material is Claude Opus 4.7, launched April 16, 2026, and Claude Sonnet 4.6, launched February 17, 2026. Both are listed with 1 million-token context windows, with Opus 4.7 priced at $5/$25 per million tokens and Sonnet 4.6 at $3/$15 per million tokens.
The main technical clue is described as a sonnet-4-8 string found on March 31, 2026, in a Claude Code source map, inside what the source calls a filter list for forbidden model names. That is a real data point in the rumor chain, but it does not confirm a shipping model, a release date, performance level, or final product name.
The market data is the second part of the rumor. According to the source, the relevant Polymarket event is not a single yes-or-no bet but a ladder of dates. The source says May 31 was around 26%, while the roughly 70% figure was attached to June 15. It also says the market had about $900 in total volume as of May 27, making it a thin sentiment signal rather than proof of Anthropic’s roadmap.
Why It Matters
The distinction matters for developers, teams, and buyers deciding whether to wait for a new Claude release or build on the models already available. A mistaken reading of the market could make a late-May release appear much more likely than the cited data supports.
For engineering teams, the practical impact is planning risk. If a team delays model evaluations, coding-agent workflows, or vendor decisions because it expects Claude 4.8 within days, it may be acting on speculation rather than confirmed product information. The source’s stronger reading is that the market sees a near-term release as plausible, with higher odds later in June and July, but not confirmed.

Will Work for Tokens Funny AI Engineer Protest Tech LLM PopSockets Adhesive PopGrip
Bold protest poster design with a fist clutching tokens, perfect for AI engineers, LLM developers, prompt engineers, and…
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Background
The rumor fits a broader pattern of developers watching model-name strings, release intervals, and prediction markets for early signs of AI model launches. The source points to a steady Sonnet cadence, the March 31 leaked string, and a rising date ladder as the main case for a possible Claude 4.8 release.
One complicating detail is Anthropic’s version pattern. The source notes that Sonnet 4.6 is current, Opus 4.7 is current, and Sonnet 4.7 has not shipped. A move straight from Sonnet 4.6 to Sonnet 4.8 would break the pairing pattern described in the source material, although it could also mean Anthropic is preparing a re-synced Opus and Sonnet release. That remains speculation.
“The 70% number is real. But the two have been welded together wrong.”
— Thorsten Meyer AI source material
“May 31 is actually ~26%.”
— Thorsten Meyer AI source material
“No Anthropic announcement, no API id, no model card, no benchmarks for 4.8.”
— Thorsten Meyer AI source material
“A sentiment gauge, not a leaked roadmap.”
— Thorsten Meyer AI source material

Portable AI Language Translator Device with Photo Recognition for Real Time Bidirectional Voice Translation – 139 Online and 20 Offline Languages, WiFi Connectivity and 1500mAh
Multilingual Online and Offline Support: This device provides translation for 139 languages and dialects online and 20 languages…
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
What Remains Unclear
It is not clear whether Anthropic will release Claude 4.8, whether any release would include both Opus and Sonnet, whether the model names would match the leaked string, or whether the timing would fall in late May, June, July, or later. Projected gains in vision tasks, software engineering benchmarks, screenshots, tables, and PDF handling are community extrapolations in the source material, not delivered capabilities.

Choosing the Right AI Engine for Your Organization
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
What’s Next
The next confirmed milestone would be an Anthropic announcement, API model listing, model card, documentation update, or benchmark release. Until then, the source material suggests teams should evaluate Claude Sonnet 4.6 and Claude Opus 4.7 for current work rather than making decisions around an unreleased model.

Gemini 3 for Beginners: A Complete Guide to AI Benchmarks in 2025 (LATEST TECH, AI, GADGET REVIEW AND GUIDE BOOK Book 44)
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Key Questions
Has Anthropic confirmed Claude 4.8?
No. The supplied source material says there is no Anthropic announcement, API ID, model card, or benchmark release for Claude 4.8.
Where did the Claude 4.8 rumor come from?
The source traces the rumor to a March 31 Claude Code source-map string labeled sonnet-4-8, release-cadence speculation, and a Polymarket date ladder.
Does the market say Claude 4.8 has a 70% chance of arriving by May 31?
According to the source material, no. It says May 31 was around 26%, while the roughly 70% figure was tied to June 15.
What Claude models are confirmed today?
The source lists Claude Opus 4.7, launched April 16, 2026, and Claude Sonnet 4.6, launched February 17, 2026, as the current confirmed models in this lineup.
Should developers wait for Claude 4.8?
The source argues against delaying work for an unconfirmed model. It points developers to current evaluations of Sonnet 4.6, Opus 4.7, and workflow improvements that can be used now.
Source: Thorsten Meyer AI