Anthropic ships Claude Haiku 5.5 at a quarter of Haiku 4.5's running cost

Anthropic's newest small model arrives two weeks after Opus 5.5 launched Sept. 22 and days after Sonnet 5.5 launched Sept. 28, making Haiku 5.5 the third model in the 5.5 generation. The company is aiming it at repetitive work, with high-volume summaries and classification as the main target, and says no Anthropic model runs faster at standard speed — which is why it suggests the model for live customer support and browser automation. Haiku 4.5, released last October, sets the pricing baseline the new model undercuts: $1 per million input tokens and $5 per million output, versus 10 cents and 50 cents for prompts up to 100,000 tokens.

The 10-cent and 50-cent rates match what OpenAI Group PBC charges for GPT-6 Luna, the low-cost model it launched last month. Anthropic's published benchmarks put Haiku 5.5 ahead of Luna on all six tests where both have a score, including 72.4% versus 48.9% on OSWorld 2.1 and 39.2% versus 16.4% on Terminal-Bench 4.0. Anthropic still points customers to Sonnet 5.5 and Opus 5.5 for complex agentic coding, suggesting the small model is not meant to replace the larger ones.

Asana Inc., which tested the model before release through its AI Teammates agent evaluation suite, reported task completion latency more than 30% lower than the model it uses today and inference on each agent turn up to 2.5 times faster. On safety, Anthropic said alignment testing turned up far fewer instances of misaligned behavior than Haiku 4.5 showed, with cybersecurity safeguards that allow more defensive work than Sonnet 5.5 permits — though penetration testing remains blocked. Whether the price advantage translates into durable savings may hinge on how the new tokenizer, which uses slightly more tokens per task, affects real-world usage patterns.