Claude Haiku 5.5: Specs and Evaluation
Anthropic released Claude Haiku 5.5 on October 7, 2026. This brief details its 1M token context, adaptive thinking, and cloud availability for engineering…
Release Specifications and Availability
Anthropic announced the release of Claude Haiku 5.5 (claude-haiku-5-5) on October 7, 2026. The source identifies this model as tuned for high-volume and latency-sensitive work. The announcement date is distinct from the current publication date of this editorial brief.
The model accepts text and image inputs and produces text outputs. It supports a context window of 1,000,000 tokens and allows up to 128,000 output tokens. The source confirms that open weights are not confirmed for this release. Pricing information is not provided in the source facts.
- Input modalities: Text, Image
- Output modality: Text
- Context window: 1,000,000 tokens
- Max output tokens: 128,000
Platform Access and Adaptive Thinking
The source states that Claude Haiku 5.5 is available on the Claude API, Claude in Amazon Bedrock, Claude Platform on AWS, Claude on Google Cloud, and Claude in Microsoft Foundry. These are the specific distribution channels listed in the official release notes.
The model includes adaptive thinking controlled by an effort parameter. The source does not explain the internal mechanism of this feature or how it adjusts computational depth. It only records the presence of the parameter and the label 'adaptive thinking.' Engineers should treat the specific behavior of this parameter as requiring empirical validation rather than assuming predefined outcomes.
Evaluation Procedure for Engineers
To evaluate the model, engineers should design tests based on the documented specifications. First, test the context limit by processing documents approaching the 1M token threshold to validate stability. Second, measure latency under high-volume conditions to assess performance against the stated tuning for latency-sensitive work. Third, compare output quality using the effort parameter at different levels to observe changes in response characteristics. Finally, validate multimodal input handling by submitting both text and image data. These steps propose practical measurements without asserting guaranteed improvements over previous models.
Artificial Analysis benchmark review
Benchmark review updated on . These scores apply to the linked artifact and recorded methodology; they do not establish the performance of a different runtime or quantized model.
| Measurement | Recorded result | Measured |
|---|---|---|
| Artificial Analysis Intelligence Index (v4.3) ↗ | 43.4 index_points | 2026-10-08 |
Review the full benchmark provenance and source methodology →
Primary sources
Frequently asked questions
What is the maximum output length for Claude Haiku 5.5?
The source specifies a maximum output of 128,000 tokens. This figure is part of the official release documentation for the model.
Is local installation possible for this model?
The source indicates that open weights are not confirmed. It does not state whether local installation is impossible or if API access is mandatory. Therefore, the hosting arrangement remains unverified beyond the listed cloud platform availability.