What Haiku 5.5 is
Claude Haiku 5.5 is an Anthropic language model. The manufacturer positions it for frequent, focused work such as classifying a ticket or extracting fields from a document. That positioning is a starting hypothesis for a test, not proof that an answer is correct.
This site provides text Chat and paired comparisons through ZenMux. It is independent of Anthropic and OpenAI. You do not need to bring a provider API key to the workspace, but submitted requests still consume usage under the displayed site credit rates.
Choose an answer you can check
A useful first task has a visible success condition. For an invoice extraction, name the required keys and decide what a missing value should look like. For a support draft, list the facts the reply must acknowledge and the promises it must not make.
A polished paragraph can hide a wrong amount or an invented commitment. Review the substance before deciding whether the model is suitable for repeated work. The input samples on the homepage include criteria, but no invented model answers.
- Preserve exact identifiers, amounts and dates.
- Return the requested structure without extra text.
- Leave missing facts missing instead of guessing.
Context size and output limits are different
The manufacturer limits below describe the direct API. A context window is the space available for the request and response together; the maximum output is a separate ceiling. Neither is a promise that every request will use that many tokens.
The connection used by this site has its own verified settings and request budget. Those limits appear in the workspace. Long requests are rejected before submission if they cannot fit the verified envelope; the tool does not silently remove part of your input. A response that reaches its output limit is marked truncated.
A conversation carries its context forward
Later Chat messages include the relevant earlier public messages, so a short follow-up can have a larger input count than its visible text suggests. Switching models keeps the visible conversation context. Hidden reasoning is not transferred as conversation content.
When context becomes too large, you can request a summary. The summary has a separate confirmation and charge. Only a complete, successfully stored summary becomes the active context; the next normal reply still requires you to send a message.
Move from trying to comparing
A single conversation answers whether Haiku can help with that example. A comparison asks whether it meets the same standard as another model on the same input. Keep your prompt fixed, include difficult cases as well as routine ones, and record why an answer fails.
Use the Sonnet page for a within-family replacement test, or the Luna page when headline API prices look similar. The Opus and Sol pages focus on more demanding text-work decisions. Your private results stay separate from these public reference pages.
Manufacturer sources
- Claude Haiku 5.5 model reference · Checked 2026-10-09
- Anthropic API pricing · Checked 2026-10-09
These sources describe the manufacturers' products. This page does not publish a site benchmark or reproduce a third-party ranking. Your saved outputs are private observations of your own inputs and settings.