Context lengths are 128,000 tokens on gpt-oss-20b and 131,072 tokens on gpt-oss-20b-free.
gpt-oss-20bgpt-oss-20b-freegpt-oss-20b is a 21-billion parameter open-weight model released by OpenAI under the Apache 2.0 license. Its core feature is a Mixture-of-Experts (MoE) architecture that uses only 3.6B active parameters, enabling low-latency inference and deployment on consumer GPUs. The model also supports fine-tuning, function calling, tool use, and structured outputs.
Developed by OpenAI, gpt-oss-20b-free is an open-weight 21B parameter model released under the Apache 2.0 license. This model utilizes a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass. It supports an expansive context window of up to 131,072 tokens, making it well-suited for long-context tasks.
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gpt-oss-20b accepts 128,000 and gpt-oss-20b-free accepts 131,072 input tokens.
gpt-oss-20b accepts text input and supports thinking, function calling and structured outputs; gpt-oss-20b-free accepts text input and supports reasoning, tool calling and long context.
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