Leaderboard · Compare · GPT-5 mini vs Gemini 2.5 Flash · Updated
GPT-5 mini vs Gemini 2.5 Flash
GPT-5 mini edges out Gemini 2.5 Flash on the composite (77.0 vs 73.3). The gap is meaningful but not decisive — see the per-benchmark breakdown below.
At a glance
| Spec | GPT-5 mini | Gemini 2.5 Flash |
|---|---|---|
| Provider | OpenAI | |
| Released | 2025-08 | 2025-04 |
| Tier | fast / cheap | fast / cheap |
| License | Closed | Closed |
| Context window | 400k | 1M |
| $ in / out (per 1M) | $0.25 / $2.00 | $0.30 / $2.50 |
Benchmark scoreboard
Higher is better on every benchmark. Δ shows GPT-5 mini − Gemini 2.5 Flash.
| Benchmark | GPT-5 mini | Gemini 2.5 Flash | Δ |
|---|---|---|---|
| Chatbot Arena Elo | 1370 | 1340 | +30 |
| MMLU-Pro | 80.1 | 79.0 | +1.1 |
| GPQA Diamond | 75.0 | 74.0 | +1.0 |
| MATH | 91.0 | 88.0 | +3.0 |
| HumanEval | 90.5 | 88.0 | +2.5 |
| SWE-Bench Verified | 60.5 | 53.3 | +7.2 |
Numbers compiled from provider technical reports and Chatbot Arena snapshots — see methodology.
OpenRouter routes GPT-5 mini, Gemini 2.5 Flash, and 100+ other LLMs behind a single API key — pay-as-you-go, no monthly minimum, fallback if a provider is down. Try OpenRouter → (affiliate · supports this site)
GPT-5 mini vs Gemini 2.5 Flash: where each one wins
GPT-5 mini is stronger on
- Arena
- MMLU-Pro
- GPQA
- MATH
- HumanEval
- SWE-Bench
Gemini 2.5 Flash is stronger on
No benchmarks where Gemini 2.5 Flash beats GPT-5 mini with comparable data.
Cost comparison
At 10M tokens/day (50/50 split), GPT-5 mini costs ~$11.25/day vs $14.00/day for Gemini 2.5 Flash — GPT-5 mini is the cheaper pick at this volume.
Verdict
GPT-5 mini edges out Gemini 2.5 Flash on the composite (77.0 vs 73.3). The gap is meaningful but not decisive — see the per-benchmark breakdown below.
If you can only pick one and your workload is unclear, route via OpenRouter and switch by request — same key, no lock-in.
Frequently asked questions
Which is better, GPT-5 mini or Gemini 2.5 Flash?
GPT-5 mini edges out Gemini 2.5 Flash on the composite (77.0 vs 73.3). The gap is meaningful but not decisive — see the per-benchmark breakdown below. GPT-5 mini wins on Arena, MMLU-Pro, GPQA, MATH, HumanEval, SWE-Bench; Gemini 2.5 Flash wins on no benchmarks.
What does GPT-5 mini cost compared to Gemini 2.5 Flash?
At 10M tokens/day (50/50 split), GPT-5 mini costs ~$11.25/day vs $14.00/day for Gemini 2.5 Flash — GPT-5 mini is the cheaper pick at this volume.
What is the context window of GPT-5 mini vs Gemini 2.5 Flash?
GPT-5 mini: 400k tokens. Gemini 2.5 Flash: 1M tokens. Gemini 2.5 Flash has the larger window — useful for long-document RAG and full-codebase prompting.
Is GPT-5 mini or Gemini 2.5 Flash open source?
GPT-5 mini: closed / proprietary. Gemini 2.5 Flash: closed / proprietary.
Can I try GPT-5 mini and Gemini 2.5 Flash on the same API key?
Yes — OpenRouter routes both models behind a single key, so you can A/B test GPT-5 mini against Gemini 2.5 Flash without juggling provider accounts.
Model deep-dives: GPT-5 mini · Gemini 2.5 Flash · Full leaderboard
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Try GPT-5 mini and Gemini 2.5 Flash now
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