---
format: "aidr-story-markdown/v1"
id: "c76b9e18844ff78c627c6a2358432c54f97f110d9456de81e38c00544eaab122"
canonical_url: "https://aidr.today/c76b9e18?lang=en"
title: "Anthropic Releases Claude Sonnet 5.5, More Than 30% Faster and Up to 30% Cheaper Than Sonnet 5"
lang: "en"
requested_lang: "en"
available_langs: ["en","vi"]
translation_fallback: null
fallback_fields: []
published_at: "2026-09-28T18:18:09.000Z"
category: "Releases"
topics: ["anthropic","llm"]
source_urls: ["https://huggingnews.com/ai/update-anthropic-releases-claude-sonnet-55-more-than-30percent-faster-an-d8d8d867","https://x.com/claudeai/status/2104633140409192757","https://x.com/AnthropicAI/status/2104633259925630995","https://x.com/tradfi/status/2104632291708576113","https://x.com/chetaslua/status/2104060831520690348","https://x.com/lyraxana/status/2104621881240244466","https://x.com/kimmonismus/status/2104182175209767016","https://news.ycombinator.com/item?id=49881850"]
summary: "Anthropic released Claude Sonnet 5.5 on Sept. 28, the second model in its Claude 5.5 family, available across Claude and its APIs. Anthropic calls it a clear upgrade over Sonnet 5 that runs more than 30% faster and costs up to 30% less for most work, and a lower-cost complement to the flagship Opus 5.5. Claude Haiku 5.5 will join the family in the coming weeks. Grey tests in Claude Code ahead of the release showed pricing of $2 per million input tokens and $10 per million output tokens, with cache reads at $0.20 per million, half the rates of Opus 5.5. The model identifier claude-sonnet-5-5 appeared in a Claude Code update before the launch. Opus 5.5, the first model in the family, was released Sept. 22 at $4/$20 per million input/output tokens and ranks No. 2 in Agent Arena and No. 1 on Xbench."
---

# Anthropic Releases Claude Sonnet 5\.5, More Than 30% Faster and Up to 30% Cheaper Than Sonnet 5

> [Open the canonical story](<https://aidr.today/c76b9e18?lang=en>)

**Published:** 2026-09-28T18:18:09.000Z
**Category:** Releases
**Topics:** anthropic, llm

## Summary

Anthropic released Claude Sonnet 5\.5 on Sept\. 28, the second model in its Claude 5\.5 family, available across Claude and its APIs\. Anthropic calls it a clear upgrade over Sonnet 5 that runs more than 30% faster and costs up to 30% less for most work, and a lower\-cost complement to the flagship Opus 5\.5\. Claude Haiku 5\.5 will join the family in the coming weeks\. Grey tests in Claude Code ahead of the release showed pricing of $2 per million input tokens and $10 per million output tokens, with cache reads at $0\.20 per million, half the rates of Opus 5\.5\. The model identifier claude\-sonnet\-5\-5 appeared in a Claude Code update before the launch\. Opus 5\.5, the first model in the family, was released Sept\. 22 at $4/$20 per million input/output tokens and ranks No\. 2 in Agent Arena and No\. 1 on Xbench\.

## Sources

- [Story source](<https://huggingnews.com/ai/update-anthropic-releases-claude-sonnet-55-more-than-30percent-faster-an-d8d8d867>)
- [Story source](<https://x.com/claudeai/status/2104633140409192757>)
- [Story source](<https://x.com/AnthropicAI/status/2104633259925630995>)
- [Supporting source](<https://x.com/tradfi/status/2104632291708576113>)
- [Supporting source](<https://x.com/chetaslua/status/2104060831520690348>)
- [Supporting source](<https://x.com/lyraxana/status/2104621881240244466>)
- [Supporting source](<https://x.com/kimmonismus/status/2104182175209767016>)
- [Discussion](<https://news.ycombinator.com/item?id=49881850>)