Releases·Model Releasefeatured
Sonnet 5.5 launch: pricing matches Sonnet 5 at $2/$10 per million tokens, cache reads at $0.20
A post announces Claude Sonnet 5.5, priced identically to Sonnet 5 at $2/$10 per million tokens. Thinking is always on by default, though developers can use the `between_tools` option to disable upfront thinking. A migration guide is available for teams moving from Sonnet 5.
420 engagement1 sourceMon, Sep 28, 2026, 06:36 PM
AI Overview
- Sonnet 5.5 keeps Sonnet 5 pricing: $2/$10 per million tokens with cache reads at $0.20.
- Thinking is always on; the `between_tools` setting turns off upfront thinking.
- A Sonnet 5.5 migration guide accompanies the launch.
Related
Releases·Model Releasefeatured
Anthropic releases Sonnet 5.5, a cheaper, 30% faster mid-tier model with Opus-level cyber capabilities
Anthropic released Claude Sonnet 5.5, the second model in the Claude 5.5 family, positioning it as a faster, lower-cost complement to Opus 5.5 for well-scoped coding and knowledge work. The company says it runs over 30% faster than Sonnet 5 and effectively costs up to 30% less per task despite identical per-token pricing, and it is the first Sonnet subject to the cybersecurity safeguards applied to Anthropic's most capable models. It is available everywhere, including Amazon Bedrock, and Haiku 5.5 is expected in the coming weeks.
Anthropic released Claude Sonnet 5.5, the second model in the Claude 5.5 family, positioning it as a faster, lower-cost complement to Opus 5.5 for well-scoped coding and knowledge work. The company says it runs over 30% faster than Sonnet 5 and effectively costs up to 30% less per task despite identical per-token pricing, and it is the first Sonnet subject to the cybersecurity safeguards applied to Anthropic's most capable models. It is available everywhere, including Amazon Bedrock, and Haiku 5.5 is expected in the coming weeks.
23022.0k engagement5 sourcesreddit, rss, xMon, Sep 28, 2026, 06:00 PM
Social·Community
Sonnet 5.5 vs Opus 5.5 vs Sonnet 5 in Claude Code and pi: results and behavioral differences on 10 coding tasks
Multiple independent developers benchmarked Anthropic's new Sonnet 5.5 against Opus 5.5 and Sonnet 5 in Claude Code and pi-agent. Sonnet 5.5 matched Opus 5.5's pass rates while running roughly twice as fast and costing one-third to one-half as much, and one tester with skills loaded could not distinguish the two models. A separate comparison found Opus 5.5 itself takes far fewer steps and tokens than Opus 5.
Multiple independent developers benchmarked Anthropic's new Sonnet 5.5 against Opus 5.5 and Sonnet 5 in Claude Code and pi-agent. Sonnet 5.5 matched Opus 5.5's pass rates while running roughly twice as fast and costing one-third to one-half as much, and one tester with skills loaded could not distinguish the two models. A separate comparison found Opus 5.5 itself takes far fewer steps and tokens than Opus 5.
Updated Tue, Sep 29, 2026, 04:23 PM — A skills-focused rerun on 2026-09-29 found Sonnet 5.5 indistinguishable from Opus 5.5 across 3 skills and 3 runs each.
11148 engagement3 sourcesredditThu, Sep 24, 2026, 08:15 PM
Releases·Model Release
Sonnet 5.5 Is Here. Look What It Can Build.
A YouTube video from Matthew Berman covers the arrival of Claude Sonnet 5.5, showcasing five demo projects built with the model (Crownfall, Bounce Lab, Marrow Manor, Splatburst, DEADLOCK) plus two comparison builds against Sonnet 5. The video highlights what the new model can build in practice rather than reporting benchmark numbers.
A YouTube video from Matthew Berman covers the arrival of Claude Sonnet 5.5, showcasing five demo projects built with the model (Crownfall, Bounce Lab, Marrow Manor, Splatburst, DEADLOCK) plus two comparison builds against Sonnet 5. The video highlights what the new model can build in practice rather than reporting benchmark numbers.
1.9k engagement2 sourcesyoutube, xTue, Sep 29, 2026, 05:04 AM
Social·Community
Anthropic sets a new AA record with Sonnet 5.5
Users digest Anthropic's Claude Sonnet 5.5 release, which set a new Artificial Analysis record for most output tokens and reportedly outperforms Opus 5.5 benchmarks on some tests. A community analysis of Anthropic's own prompting guide found Sonnet 5.5 scores lower at max effort than xhigh on a coding benchmark because extra code-review subagents make edits outside the task. The release landed a day before OpenAI's Dev Day, where OpenAI reportedly plans 20+ launches.
Users digest Anthropic's Claude Sonnet 5.5 release, which set a new Artificial Analysis record for most output tokens and reportedly outperforms Opus 5.5 benchmarks on some tests. A community analysis of Anthropic's own prompting guide found Sonnet 5.5 scores lower at max effort than xhigh on a coding benchmark because extra code-review subagents make edits outside the task. The release landed a day before OpenAI's Dev Day, where OpenAI reportedly plans 20+ launches.
Updated Tue, Sep 29, 2026, 03:44 PM — Users report Sonnet 5.5 and Opus 5.5 outperforming Sol and Astra; OpenAI reportedly preps 20+ Dev Day launches
121316 engagement5 sourcesredditMon, Sep 28, 2026, 06:51 PM
Social·Community
Sonnet 5.5 vs Sonnet 5 vs Sonnet 4.6 guardrails and guidelines
A Reddit user ranks Claude Sonnet versions by guardrail behavior, placing Sonnet 4.6 above Sonnet 5.5 above Sonnet 5. They find Sonnet 5.5 less aggressive in censoring benign content than Sonnet 5 but less flexible than Sonnet 4.6, particularly for story generation. The post solicits community opinions on whether to send Anthropic feedback asking for looser policies.
A Reddit user ranks Claude Sonnet versions by guardrail behavior, placing Sonnet 4.6 above Sonnet 5.5 above Sonnet 5. They find Sonnet 5.5 less aggressive in censoring benign content than Sonnet 5 but less flexible than Sonnet 4.6, particularly for story generation. The post solicits community opinions on whether to send Anthropic feedback asking for looser policies.
8 engagement1 sourceredditWed, Sep 30, 2026, 04:11 PM