Reka Flash 3

Reka Flash 3 - Compact reasoning model

Reka Flash 3 is Reka’s 21B-parameter reasoning model for compact deployments, with documentation emphasizing explicit reasoning traces, function calling, and a long but practical context window.

Defining Characteristics

• 21B parameter reasoning model: Reka describes Flash 3 as a 21-billion-parameter model trained from scratch for general-purpose reasoning.
• Explicit reasoning tags: The model uses <reasoning> tags to expose internal thought traces in supported integrations.
• Budget forcing for latency control: Provider documentation says Flash 3 supports a budget forcing mechanism to cap reasoning steps and control latency.
• 66K context window: Public listings document a 65,536/66K-token context window and matching maximum output size.

Core Design

• The model is text-first and English-focused in the official model card, with on-device or low-latency deployment called out as a key use case.
• Reka also positions Flash 3 as suitable for function calling, coding, and instruction following.