Haiku 5.5

Haiku 5.5 is an independently operated website for using language models and comparing their responses. It combines an online chat interface with side-by-side model comparisons, supporting people who want to evaluate a prompt before deciding which model to use for a particular task. The website is a third-party product, not an official website of Anthropic or OpenAI.

The single-model chat mode is useful when you already know which available model you want to try. The comparison mode lets you send the same prompt to multiple models and inspect the answers together. This gives you a concrete basis for comparing the responses to your own task instead of relying only on general model descriptions or benchmark scores. It does not automatically establish that one model is best for every use case.

For repeated evaluations, the product also supports batch comparison using CSV inputs. Private history keeps previous work accessible, and CSV or PDF exports provide a way to keep results outside the interface. These features are intended for users who need to review more than a single answer, including developers testing prompts, writers evaluating draft responses, and individuals comparing assistants for everyday work.

Alongside the interactive tools, the website contains model information and usage guides. An API cost calculator helps visitors explore token-based cost estimates using published model prices. Those API estimates are separate from the website's own credit billing and should not be treated as a quote for an individual chat session.

AI generation on the website uses prepaid credits rather than a recurring subscription. The credits consumed depend on the selected model and usage. Users should review the current pricing and available models on the website before purchasing. Outputs are generated by AI and should be checked before being used in important decisions or published as factual material. The site is personally operated, and the product's purpose is practical access and comparison, not a claim of affiliation with model providers.