Gemini 2.5 Flash-Lite vs GPT OSS 20B vs Mistral Small 3.2

Gemini 2.5 Flash-Lite is the better all-round choice, scoring 71/100 against GPT OSS 20B (64) and Mistral Small 3.2 (60). It leads on inputs & features and context window. GPT OSS 20B wins on capability and price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

GPT OSS 20B is cheaper at $0.07 input / $0.295 output per million tokens (median across 18 API providers). Mistral Small 3.2 costs $0.10 input / $0.30 output per million tokens (official Mistral API price); Gemini 2.5 Flash-Lite costs $0.10 input / $0.40 output per million tokens (official Google API price). At a typical mix of three input tokens to one output token, that is $0.126 per million tokens for GPT OSS 20B versus $0.15 for Mistral Small 3.2 (1.2× as much) and $0.175 for Gemini 2.5 Flash-Lite (1.4× as much).

GPT OSS 20B scores higher on the Capabilities Index (ECI): GPT OSS 20B 137.8 (#108 of 148), Gemini 2.5 Flash-Lite 133.9 (#118 of 148) and Mistral Small 3.2 131.7 (#123 of 148). The confidence ranges of the top two overlap (133.0–139.6 vs 129.8–136.3), so treat the gap as small.

There are no published SWE-bench Verified results for Gemini 2.5 Flash-Lite, GPT OSS 20B and Mistral Small 3.2 yet, so there is no like-for-like coding score. On overall capability, GPT OSS 20B leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Gemini 2.5 Flash-Lite has the largest context window at 1,048,576 tokens, against 131,072 for GPT OSS 20B and 128,000 for Mistral Small 3.2. Maximum output per response: Gemini 2.5 Flash-Lite up to 65,536, GPT OSS 20B up to 32,768, Mistral Small 3.2 up to 16,384 tokens.

Gemini 2.5 Flash-Lite accepts text, images, PDFs, audio and video; GPT OSS 20B accepts text; Mistral Small 3.2 accepts text and images. Gemini 2.5 Flash-Lite handles the widest range of inputs.

GPT OSS 20B and Mistral Small 3.2 publishes its weights and can be self-hosted; Gemini 2.5 Flash-Lite is proprietary.

GPT OSS 20B is the newest, released Aug 5, 2025. Mistral Small 3.2 came out Jun 20, 2025; Gemini 2.5 Flash-Lite came out Jun 17, 2025. Knowledge cutoff: Gemini 2.5 Flash-Lite Jan 2025, Mistral Small 3.2 Mar 2025.

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.