Compare/Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) vs gpt-oss-20B (low)

Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)vsgpt-oss-20B (low)

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

Google

Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)

Input
$0/M
Output
$0/M
Speed
TTFT
OpenAI

gpt-oss-20B (low)

Input
$0.06/M
Output
$0.2/M
Speed
265 tok/s
TTFT
0.42s

Winner by Category

Cheaper
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
Faster (tok/s)
gpt-oss-20B (low)
Lower Latency
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
Benchmarks (7-4)
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)

Pricing Comparison

MetricGemini 2.5 Flash Preview (Sep '25) (Non-reasoning)gpt-oss-20B (low)
Input ($/M tokens)$0$0.06
Output ($/M tokens)$0$0.2
Cost for 1M input + 100K output tokens:
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)$0.00
gpt-oss-20B (low)$0.08

Speed Comparison

Output Speed (tokens/s) — higher is better
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
gpt-oss-20B (low)
265 tok/s
Time to First Token (seconds) — lower is better
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)
gpt-oss-20B (low)
0.42s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
25.720.8
Coding Index
22.114.4
Math Index
56.762.3
GPQA Diamond
76.6%61.1%
MMLU-Pro
83.6%71.8%
LiveCodeBench
62.5%65.2%
AIME 2025
56.7%62.3%
MATH-500
Humanity's Last Exam
7.8%5.1%
SciCode
37.5%34.0%
IFBench
43.5%57.8%
TerminalBench
14.4%4.5%
Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning)7 wins
4 winsgpt-oss-20B (low)

Frequently Asked Questions

Which is cheaper, Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) or gpt-oss-20B (low)?

Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) is cheaper overall. Its blended price (3:1 input/output ratio) is $0.00/M tokens vs $0.10/M for gpt-oss-20B (low).

Which model performs better on benchmarks?

Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) wins 7 out of 12 benchmarks compared to 4 for gpt-oss-20B (low). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

gpt-oss-20B (low) generates tokens faster at 265 tok/s vs 0 tok/s. Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) also has lower time-to-first-token (0.00s vs 0.42s).

When should I use Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) vs gpt-oss-20B (low)?

Choose based on your priorities: Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) for lower cost, Gemini 2.5 Flash Preview (Sep '25) (Non-reasoning) for stronger benchmark performance, and gpt-oss-20B (low) for faster generation. For latency-sensitive apps, check the TTFT comparison above.