---
title: "Claude Sonnet 5 发布：性能接近 Opus 但价格暗涨"
source: "Simon Willison 博客（Atom）"
source_tier: "t2"
url: "https://simonwillison.net/2026/Jun/30/claude-sonnet-5/#atom-everything"
permalink: "https://feed.astralor.com/items/itm_ab37cad98a0d69714af8c016"
published: "2026-06-30T21:23:02.000Z"
score: 65
channel: "ai"
tags: ["Anthropic","Claude Sonnet 5","上下文长度","分词器","定价策略"]
---

# Claude Sonnet 5 发布：性能接近 Opus 但价格暗涨

## 速览

Anthropic 发布 Claude Sonnet 5，性能接近 Opus 4.8 但价格更低。然而新分词器导致输入 token 增加约 30%，实际成本上升。模型支持 100 万 token 上下文、12.8 万输出 token，默认开启自适应思考，不再支持 temperature 等采样参数。网络安全能力低于 Mythos 5，安全措施与 Opus 4.7/4.8 一致。

## 关键点

- 性能接近 Opus 4.8，但定价与 Sonnet 4.6 相同（输入 $3/M，输出 $15/M，8 月 31 日前有折扣）
- 新分词器使英文输入 token 增加约 40%，中文不变，实际成本上涨约 30%
- 100 万 token 上下文窗口，12.8 万 token 最大输出
- 默认开启自适应思考，不再支持 temperature、top_p、top_k 参数

## 全文

What's new in Claude Sonnet 5 Claude Sonnet 5 came out this morning. I always head straight for the "what's new" developer docs because they tend to have more actionable information than the official announcement post. Anthropic say of Sonnet 5 that "its performance is close to that of Opus 4.8, but at lower prices". The system card helps explain how they were able to release the model without being blocked by the US government: Sonnet 5 is significantly less capable at cyber tasks than Mythos 5: its safeguards are thus similar to those we apply to Opus 4.7 and Opus 4.8 (models that are more capable than Sonnet 5 but much less capable than Mythos 5). Of note from the "what's new" API changes: Sampling parameters temperature, top_p, top_k are no longer supported. It has a 1 million token context window and 128,000 maximum output tokens. It features "the same set of tools and platform features as Claude Sonnet 4.6" Adaptive thinking is on by default, unless you specify "thinking": {type: "disabled"}. The pricing is the same as Sonnet 4.6: $3/million input, $15/million input, with an introductory discount to $2/$10 until 31st August. But... The model has a new tokenizer, where "The same input text produces approximately 30% more tokens than on Claude Sonnet 4.6." - effectively a 30% price increase. I used my Claude Token Counter tool to try out the new tokenizer. Here are my results for several larger documents: Document Sonnet 4.6 Opus 4.7 Sonnet 5 Universal Declaration of Human Rights (English) 2,356 3,3471.42x 3,3411.42x Universal Declaration of Human Rights (Spanish) 3,572 4,7531.33x 4,7471.33x Universal Declaration of Human Rights (Chinese, Mandarin Simplified) 3,334 3,3661.01x 3,3601.01x sqlite_utils/db.py (4,279 lines of Python) 44,014 56,1181.28x 56,1131.27x So the new token is roughly 1.4x times more expensive for English, 1.33x for Spanish, 1.28x for Python code and effectively the same cost for Simplified Mandarin. Here's the pelican. It's nothing to write home about. Sonnet 5 thinks it looks like a goose. Via Hacker News Tags: ai, generative-ai, llms, anthropic, claude, llm-pricing, pelican-riding-a-bicycle, llm-release

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引用前请核对原文;本文由星际流动整理:https://feed.astralor.com/items/itm_ab37cad98a0d69714af8c016