gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for lower-latency inference and deplo…
Model details →OpenAI: gpt-oss-20b (free) vs xAI: Grok 3 Mini
OpenAI: gpt-oss-20b (free) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
A lightweight model that thinks before responding. Fast, smart, and great for logic-based tasks that do not require deep domain knowledge. The raw thinking traces are accessible.
Model details →Side-by-side comparison
| Capability | OpenAI: gpt-oss-20b (free) | xAI: Grok 3 Mini | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 131K | 131K | Tie |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $0.00 | $0.30 | 🏆 OpenAI: gpt-oss-20b (free) |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $0.00 | $0.50 | 🏆 OpenAI: gpt-oss-20b (free) |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | — | — | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is OpenAI: gpt-oss-20b (free) better than xAI: Grok 3 Mini?
OpenAI: gpt-oss-20b (free) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between OpenAI: gpt-oss-20b (free) and xAI: Grok 3 Mini?
Input: $0.00 vs $0.30 per 1M tokens. Output: $0.00 vs $0.50 per 1M tokens.
What context windows do OpenAI: gpt-oss-20b (free) and xAI: Grok 3 Mini support?
OpenAI: gpt-oss-20b (free) supports up to 131K tokens. xAI: Grok 3 Mini supports up to 131K tokens.
Do both OpenAI: gpt-oss-20b (free) and xAI: Grok 3 Mini support tool calling?
OpenAI: gpt-oss-20b (free): yes. xAI: Grok 3 Mini: yes.