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- Oct 14, 202650% CONFIDENCEfrom the source
Claude Haiku 5.5 Released
- Anthropic has promised Claude Haiku 5.5 twice: the Opus 5.5 announcement on 22 September said Sonnet 5.5 and Haiku 5.5 "will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety", and the Sonnet 5.5 post on 28 September said Haiku 5.5 "will join the Claude 5.5 family in the coming weeks"[1][5][6]
- Anthropic describes it as "built for high-volume and cost-sensitive applications"; CNBC calls it "the cheapest offering in the suite", and TechCrunch notes Anthropic "didn't give a firm date"[1][4][5]
- The date is a prediction: last generation Haiku 4.5 (15 October 2025) arrived 16 days after Sonnet 4.5 (29 September 2025), which from Sonnet 5.5's 28 September launch points to about 14 October 2026[2][5]
- Until it ships, Anthropic's lineup still lists Claude Haiku 4.5 as its fastest model[3]
Notable features
- Anthropic has published no price, context window or benchmarks for Haiku 5.5; it says only that it shares "many of the same improvements to performance, efficiency, and safety" as Opus 5.5[6]
- The rest of the Claude 5.5 family has a 1M-token context window, 128K max output and a June 2026 knowledge cutoff, where Haiku 4.5 has 200K, 64K and February 2025[3]
- The model it replaces, Haiku 4.5, costs $1 per million input tokens and $5 per million output tokens, against Sonnet 5.5's $2 and $10[2][3][5]
References 681% CONFIDENCEOverall confidence: 81%How well the pin's source and references back up its dates.Weighted average of how firmly 6 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins at 75% confidence or better
The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
- [1]50%cnbc.com/2026/09/28/anthropic-sonnet-5-5-launch.htmlcnbc.com· Posted Sep 28, 2026· Starts Oct 14, 2026 ✓· 17% of score
Estimated: Anthropic's[2][5][6] 28 September Sonnet 5.5 post says Claude[3] Haiku 5.5 "will join the Claude 5.5 family in the coming weeks" and TechCrunch[4] says it gave no firm date; last generation, Anthropic's own pages date Sonnet 4.5 to 29 September 2025 and Haiku 4.5 to 15 October 2025, 16 days later, and 16 days after Sonnet 5.5 is Wednesday 14 October 2026, the same weekday Haiku 4.5 launched.
- [2]85%Claude Haiku \ Anthropicanthropic.com· Added Sep 28, 2026· 17% of score
Anthropic's[5][6] Haiku page still leads with Claude[3] Haiku 4.5, dated "Oct 15, 2025" and priced from $1 per million input and $5 per million output tokens - the model Haiku 5.5 replaces, and the release that came 16 days after Sonnet 4.5.
- [3]85%Models overview - Claude Platform Docsplatform.claude.com· Added Sep 28, 2026· 17% of score
Anthropic's[2][5][6] current lineup lists Claude Haiku 4.5 (claude-haiku-4-5-20251001) as the Haiku, with a 200K-token context, 64K max output, a February 2025 reliable knowledge cutoff and retirement "not sooner than October 15, 2026", beside the Claude 5.5 models' 1M context and June 2026 cutoff.
- [4]85%Anthropic releases Sonnet 5.5, which it calls a significantly cheaper, faster work partner | TechCrunchtechcrunch.com· Published Sep 28, 2026· 17% of score
TechCrunch: Anthropic[2][5][6] "plans to release a new version of Haiku - its smallest model - in the coming weeks, although it didn't give a firm date as to when that would happen."
- [5]90%Claude Sonnet 5.5anthropic.com· Published Sep 28, 2026· 17% of score
Anthropic's[2][6] Sonnet 5.5 announcement (28 September 2026) says Claude[3] Haiku 5.5 'will join the Claude 5.5 family in the coming weeks' and is 'built for high-volume and cost-sensitive applications'; gives Sonnet 5.5's $2/$10 per million token price. No date for Haiku 5.5.
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