GPT-5 Mini vs Gemini 2.5 Flash Preview 05-20
Too close to call on our weighted score (Gemini 2.5 Flash Preview 05-20 67, GPT-5 Mini 64). The right pick depends on what you value most.
OpenAIGPT-5 Mini
64/100- ECI145.4
- Price$0.25 / $2.00
- Context400K
GoogleGemini 2.5 Flash Preview 05-20
67/100- ECI141.5
- Price$0.146 / $1.96
- Context1.05M
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Make it a three-way comparison.
Too close to call
It is close. Our weighted score puts them within 3 points (Gemini 2.5 Flash Preview 05-20 67/100, GPT-5 Mini 64/100), so choose by what matters most for your work: GPT-5 Mini for raw capability, Gemini 2.5 Flash Preview 05-20 on price and Gemini 2.5 Flash Preview 05-20 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5 MiniCapabilities Index (ECI): GPT-5 Mini 145.4 · Gemini 2.5 Flash Preview 05-20 141.5
- Lowest priceGemini 2.5 Flash Preview 05-20Gemini 2.5 Flash Preview 05-20 $0.60 · GPT-5 Mini $0.688 per 1M tokens (3:1 blend)
- Longest contextGemini 2.5 Flash Preview 05-20Gemini 2.5 Flash Preview 05-20 1,048,576 · GPT-5 Mini 400,000 tokens
- Widest inputsGemini 2.5 Flash Preview 05-20GPT-5 Mini: Text, Images · Gemini 2.5 Flash Preview 05-20: Text, Images, PDFs, Audio, Video
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | GPT-5 Mini | Gemini 2.5 Flash Preview 05-20 |
|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 71 | 66 |
| Price | 25% | 55 | 58 |
| Inputs & features | 15% | 70 | 90 |
| Context window | 10% | 44 | 61 |
| Overall | 100% | 64/100 | 67/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5 MiniOpenAI | Gemini 2.5 Flash Preview 05-20Google |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 145.4 (best) | 141.5 |
| ECI rank | #87 of 165 (best) | #106 of 165 |
| GPQA DiamondGraduate-level science questions | 75.0% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 46.7% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 86.7% (best) | 70.8% |
| SWE-bench VerifiedFixing real GitHub issues | 64.7% | — |
| SimpleQA VerifiedShort factual questions | 21.6% | — |
| Price per million tokens | ||
| Input | $0.25 | $0.146 (best) |
| Output | $2.00 | $1.96 (best) |
| Cached input | $0.025 | — |
| Blended (3:1) | $0.688 | $0.60 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official OpenAI API | Median of 2 providers |
| Limits | ||
| Context window | 400,000 tokens | 1,048,576 tokens (best) |
| Max output | 128,000 tokens (best) | 65,536 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | Yes |
| Audio | No | Yes |
| Video | No | Yes |
| Reasoning | Yesminimal · low · medium · high | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | gpt-5-mini | — |
| API providers | 35 (best) | 2 |
| Released | Aug 7, 2025 | May 20, 2025 |
| Knowledge cutoff | May 30, 2024 | Jan 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5 Mini$6.50
- Gemini 2.5 Flash Preview 05-20$5.39
Which should you choose?
Which is better: GPT-5 Mini or Gemini 2.5 Flash Preview 05-20?
It is close. Our weighted score puts them within 3 points (Gemini 2.5 Flash Preview 05-20 67/100, GPT-5 Mini 64/100), so choose by what matters most for your work: GPT-5 Mini for raw capability, Gemini 2.5 Flash Preview 05-20 on price and Gemini 2.5 Flash Preview 05-20 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, GPT-5 Mini or Gemini 2.5 Flash Preview 05-20?
Gemini 2.5 Flash Preview 05-20 is cheaper at $0.146 input / $1.96 output per million tokens (median across 2 API providers). GPT-5 Mini costs $0.25 input / $2.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $0.60 per million tokens for Gemini 2.5 Flash Preview 05-20 versus $0.688 for GPT-5 Mini (1.1× as much).
Which scores higher on benchmarks?
GPT-5 Mini scores higher on the Capabilities Index (ECI): GPT-5 Mini 145.4 (#87 of 165) and Gemini 2.5 Flash Preview 05-20 141.5 (#106 of 165). Their confidence ranges do not overlap (143.5–147.1 vs 139.3–142.9), so the gap is a real one. On individual benchmarks: OTIS Mock AIME 2024–2025 — GPT-5 Mini 86.7%, Gemini 2.5 Flash Preview 05-20 70.8%.
Which is better for coding?
There are no published SWE-bench Verified results for Gemini 2.5 Flash Preview 05-20 yet, so there is no like-for-like coding score. On overall capability, GPT-5 Mini leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
Gemini 2.5 Flash Preview 05-20 has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5 Mini. Maximum output per response: GPT-5 Mini up to 128,000, Gemini 2.5 Flash Preview 05-20 up to 65,536 tokens.
Which can read images, PDFs, audio or video?
GPT-5 Mini accepts text and images; Gemini 2.5 Flash Preview 05-20 accepts text, images, PDFs, audio and video. Gemini 2.5 Flash Preview 05-20 handles the widest range of inputs.
Are any of these open source?
No. GPT-5 Mini and Gemini 2.5 Flash Preview 05-20 are proprietary and only available through APIs and apps.
Which is newer?
GPT-5 Mini is the newest, released Aug 7, 2025. Gemini 2.5 Flash Preview 05-20 came out May 20, 2025. Knowledge cutoff: GPT-5 Mini May 30, 2024, Gemini 2.5 Flash Preview 05-20 Jan 2025.
How do you decide the winner?
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.
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