Claude Sonnet 5 Release & Upgrade Guide
According to multiple reliable sources, Anthropic is very likely to release Claude Sonnet 5 this week or in the near term (possibly codenamed claude-sonnet-5-20260203). This news has drawn widespread attention, and many users are already looking forward to the performance of the next-generation Claude models.
The Claude Sonnet 5 "Sand Fox" Codenane Leak Explained
Recently, a user spotted the string claude-sonnet-5@20260203 in Google Cloud Vertex AI logs. Its naming format exactly matches the convention for Claude models on the Vertex platform (usually model name + date). This is being interpreted as a sign that Anthropic may have a major release window around February 3, 2026.
It's worth emphasizing: the appearance of a string doesn't necessarily mean the model will be released immediately — it could also be internal testing or pre-deployment. But given Anthropic's recent release cadence, this leak is fairly credible and worth keeping an eye on.
Expected Claude Sonnet 5 Highlights (Based on Current Leaks)
- Context window boosted to 1M tokens, great for ultra-long document processing and complex conversations
- Priced at only half of the current Opus 4.5, offering far better value for money
- Best-in-class performance on agentic and coding tasks, poised to become the go-to choice for developers
- Supports TPU hardware acceleration, with faster inference and lower latency
Is this a genuine leak or a deliberate teaser by Anthropic? The answer will be revealed soon.
How Can Users in China Upgrade Claude Pro? The Most Stable 2026 Tutorial
Because of payment restrictions in China, directly subscribing to Claude Pro with an international Visa/MasterCard is often declined or flagged by risk controls. If you want to stably experience the full Claude Pro feature set (such as Claude Code, Artifacts, Projects, higher limits, etc.), you can choose a safe third-party direct top-up channel.
We recommend a direct top-up service that requires no account name or password and is simple to operate: https://claudezh.cn
Pros: Top up in just three steps; with a clean network environment the account stays highly stable — ideal for long-term use.
Detailed Upgrade Steps (With Screenshots)
Step 1: Get a top-up code or card key
Go to https://claudezh.cn , purchase the appropriate Claude Pro top-up amount, then get your card key/top-up code.
Step 2: Find your Claude user ID
Log in to https://claude.ai , click the avatar in the top-right corner → Settings, or go directly to:
https://claude.ai/settings
The page shows your Organization ID (your account's unique ID).
Step 3: Fill in the details to complete the direct top-up
Return to the top-up platform, paste your Organization ID, enter your card key, and submit to complete the upgrade. It usually arrives within a few minutes.
Friendly tips:
- If you don't have a Claude account yet, you can register directly with an email, or obtain one through an official channel.
- Keep a clean network while using it (avoid frequently switching IPs) to significantly reduce the risk of account bans.
- Once upgraded, you unlock all of Claude Pro's advanced features and can freely use the latest models.
When Claude Sonnet 5 officially launches, Pro users will get priority access, so we recommend upgrading early.
Stay tuned for updates — Claude Sonnet 5 is definitely worth looking forward to!