Anthropic’s next big AI release, Claude Sonnet 5, is reportedly just around the corner. In the past few days, rumors and leaks around Sonnet 5 have become louder. Over the weekend, multiple reports hinted that Anthropic could release Claude Sonnet 5 on February 3, 2026, which is today.
Claude Sonnet 5 release is imminent, leaks hint at big upgrades
For those uninitiated, we are officially inside Super Bowl week, so there’s a high chance that the rumors could be true. In the past, we have witnessed other AI brands promoting their AI products, models, and vision during this time. Last year, Super Bowl ads showcased AI from OpenAI, Google, and Meta. But the speculation around Claude Sonnet 5 hasn’t just come out of a fluke.
A user on X has combined all the leaks into a post, and it includes some detailed information about Sonnet 5’s release and features, albeit unverified. Apparently, a Vertex AI error log reportedly listed claude-sonnet-5@20260203, suggesting the model already exists inside Google’s infrastructure and is simply waiting to be switched on. While Anthropic hasn’t confirmed anything officially, the presence of that identifier strongly hints that Sonnet 5 could release today.
claude-sonnet-5-20260203 https://t.co/bsomENEN4v
— leo 🐾 (@synthwavedd) February 1, 2026
Claude Sonnet 5 reportedly carries the codename “Fennec.” According to leaks, Anthropic is looking at this release as a generational step forward, with insiders even claiming it sits ahead of Google Gemini’s upcoming Snow Bunny model. As always, those comparisons should be taken cautiously, but they do set expectations high.
Early hands-on testing has also revealed some interesting details. Folks over at Testing Catalog, in their report, suggested that Claude Sonnet 5 already shows stronger coding output than Claude Opus 4.5 in certain workflows. The upcoming model reportedly focuses heavily on UI-heavy tasks, structured layouts, and even visual-style code generation. One example that keeps coming up is an ASCII world map prompt, which testers described as unusually complete and detailed.
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Possibility of massive 1 million tokens at an affordable rate
Some leaks have even claimed that Sonnet 5 keeps a massive 1 million token context window, although the tested build was capped at 128k tokens. So, we are assuming that the final release version could differ, as the true figure remains unclear. Interestingly, pricing rumors have been much more consistent. Sonnet 5 is expected to be a faster, lower-cost model, possibly up to 50% cheaper than Claude Opus 4.5. There are also claims that it’s optimized on Google TPUs, which could explain the performance gains and lower latency.
Moving on, another big, rumored upgrade is Claude Code. Leaks suggest Sonnet 5 can spawn multiple specialized sub-agents, handling backend work, QA, or research in parallel. A so-called “Dev Team” mode could let these agents work autonomously after receiving a brief, mimicking a small human team. All that said, these details point to an imminent reveal. If Anthropic delivers on even part of what’s leaking, Claude Sonnet 5 could become its most important “workhorse” model yet.
