GPT OSS 20B vs Gemini 2.5 Flash-Lite Preview 06-17

Gemini 2.5 Flash-Lite Preview 06-17 is the better all-round choice, scoring 67/100 against GPT OSS 20B (61). 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 / $0.25 output per million tokens (median across 37 API providers). Gemini 2.5 Flash-Lite Preview 06-17 costs $0.12 input / $0.48 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $0.115 per million tokens for GPT OSS 20B versus $0.21 for Gemini 2.5 Flash-Lite Preview 06-17 (1.8× as much).

GPT OSS 20B scores higher on the Capabilities Index (ECI): GPT OSS 20B 137.8 (#122 of 165) and Gemini 2.5 Flash-Lite Preview 06-17 133.8 (#132 of 165). The confidence ranges of the top two overlap (133.1–139.7 vs 130.1–136.1), so treat the gap as small.

There are no published SWE-bench Verified results for GPT OSS 20B and Gemini 2.5 Flash-Lite Preview 06-17 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. Both support tool calling for agent workflows.

Gemini 2.5 Flash-Lite Preview 06-17 has the largest context window at 1,048,576 tokens, against 131,072 for GPT OSS 20B. Maximum output per response: GPT OSS 20B up to 32,768, Gemini 2.5 Flash-Lite Preview 06-17 up to 65,536 tokens.

GPT OSS 20B accepts text; Gemini 2.5 Flash-Lite Preview 06-17 accepts text, images, PDFs, audio and video. Gemini 2.5 Flash-Lite Preview 06-17 handles the widest range of inputs.

GPT OSS 20B publishes its weights and can be self-hosted; Gemini 2.5 Flash-Lite Preview 06-17 is proprietary.

GPT OSS 20B is the newest, released Aug 5, 2025. Gemini 2.5 Flash-Lite Preview 06-17 came out Jun 17, 2025. Knowledge cutoff: GPT OSS 20B Jun 2024, Gemini 2.5 Flash-Lite Preview 06-17 Jan 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 Nov 2, 2026.