Pareto 26.9

Unbiased AI released Pareto 26.9 on 17 September 2026 as its first model. Rather than a single set of weights, it pits several frontier and open-source models against one another on each request and returns one answer per API call. It is served through the company's own platform and through OpenRouter.

What Pareto 26.9 offers

• Blended responses: runs several models on each request and returns one answer.
• Prompt cache kept: does not switch models part-way through a conversation, which the company says keeps the prompt cache intact.
• Text and image input: accepts text and images and returns text.
• Vendor benchmarks: five figures published by the vendor, including 74 on DeepSWE and 88 on ArXivMath, with no independent score published at the time of writing.

Key facts

• Context window: 262,144 tokens, with up to 131,072 output tokens
• Model identifier: pareto
• Built by: Circuit & Chisel, which works remotely across the US and Canada