DeepSeek-V3.1 vs Gemini 2.5 Flash vs GPT-5 Mini
Too close to call on our weighted score (Gemini 2.5 Flash 68, GPT-5 Mini 65, DeepSeek-V3.1 55). The right pick depends on what you value most.
DeepSeekDeepSeek-V3.1
55/100- ECI139.9
- Price$0.385 / $1.25
- Context131K
GoogleGemini 2.5 Flash
68/100- ECI140.8
- Price$0.30 / $2.50
- Context1.05M
OpenAIGPT-5 Mini
65/100- ECI145.5
- Price$0.25 / $2.00
- Context400K
Too close to call
It is close. Our weighted score puts them within 2 points (Gemini 2.5 Flash 68/100, GPT-5 Mini 65/100, DeepSeek-V3.1 55/100), so choose by what matters most for your work: GPT-5 Mini for raw capability, DeepSeek-V3.1 on price and Gemini 2.5 Flash for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGPT-5 MiniCapabilities Index (ECI): GPT-5 Mini 145.5 · Gemini 2.5 Flash 140.8 · DeepSeek-V3.1 139.9
- Lowest priceDeepSeek-V3.1DeepSeek-V3.1 $0.601 · GPT-5 Mini $0.688 · Gemini 2.5 Flash $0.85 per 1M tokens (3:1 blend)
- Longest contextGemini 2.5 FlashGemini 2.5 Flash 1,048,576 · GPT-5 Mini 400,000 · DeepSeek-V3.1 131,072 tokens
- Widest inputsGemini 2.5 FlashDeepSeek-V3.1: Text · Gemini 2.5 Flash: Text, Images, PDFs, Audio, Video · GPT-5 Mini: Text, Images
- Self-hostingDeepSeek-V3.1Publishes downloadable weights (MIT License)
| Measure | Weight | DeepSeek-V3.1 | Gemini 2.5 Flash | GPT-5 Mini |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 65 | 67 | 72 |
| Price | 25% | 60 | 53 | 58 |
| Inputs & features | 15% | 35 | 100 | 70 |
| Context window | 10% | 24 | 61 | 44 |
| Overall | 100% | 55/100 | 68/100 | 65/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | DeepSeek-V3.1DeepSeek | Gemini 2.5 FlashGoogle | GPT-5 MiniOpenAI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 139.9 | 140.8 | 145.5 (best) |
| ECI rank | #100 of 148 | #97 of 148 | #77 of 148 (best) |
| GPQA DiamondGraduate-level science questions | — | — | 75.0% |
| FrontierMath Tiers 1–3Research-level mathematics | — | — | 46.7% |
| OTIS Mock AIME 2024–2025Competition mathematics | — | — | 86.7% |
| SWE-bench VerifiedFixing real GitHub issues | — | — | 64.7% |
| SimpleQA VerifiedShort factual questions | — | — | 21.6% |
| Price per million tokens | |||
| Input | $0.385 | $0.30 | $0.25 (best) |
| Output | $1.25 (best) | $2.50 | $2.00 |
| Cached input | — | $0.03 | $0.025 (best) |
| Blended (3:1) | $0.601 (best) | $0.85 | $0.688 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Median of 8 providers | Official Google API | Official OpenAI API |
| Limits | |||
| Context window | 131,072 tokens | 1,048,576 tokens (best) | 400,000 tokens |
| Max output | 8,192 tokens | 65,536 tokens | 128,000 tokens (best) |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | No | Yes | Yes |
| PDFs | No | Yes | No |
| Audio | No | Yes | No |
| Video | No | Yes | No |
| Reasoning | Yes | Yes | Yesminimal · low · medium · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | No | Yes | Yes |
| Availability | |||
| Weights | OpenMIT License | Proprietary | Proprietary |
| API model ID | — | gemini-2.5-flash | gpt-5-mini |
| API providers | 8 | 22 | 23 (best) |
| Released | Aug 21, 2025 | Jun 17, 2025 | Aug 7, 2025 |
| Knowledge cutoff | — | Jan 2025 | May 30, 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- DeepSeek-V3.1$6.35
- Gemini 2.5 Flash$8.00
- GPT-5 Mini$6.50
Which should you choose?
Which is better: DeepSeek-V3.1, Gemini 2.5 Flash or GPT-5 Mini?
It is close. Our weighted score puts them within 2 points (Gemini 2.5 Flash 68/100, GPT-5 Mini 65/100, DeepSeek-V3.1 55/100), so choose by what matters most for your work: GPT-5 Mini for raw capability, DeepSeek-V3.1 on price and Gemini 2.5 Flash for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, DeepSeek-V3.1, Gemini 2.5 Flash or GPT-5 Mini?
DeepSeek-V3.1 is cheaper at $0.385 input / $1.25 output per million tokens (median across 8 API providers). GPT-5 Mini costs $0.25 input / $2.00 output per million tokens (official OpenAI API price); Gemini 2.5 Flash costs $0.30 input / $2.50 output per million tokens (official Google API price). At a typical mix of three input tokens to one output token, that is $0.601 per million tokens for DeepSeek-V3.1 versus $0.688 for GPT-5 Mini (1.1× as much) and $0.85 for Gemini 2.5 Flash (1.4× as much).
Which scores higher on benchmarks?
GPT-5 Mini scores higher on the Capabilities Index (ECI): GPT-5 Mini 145.5 (#77 of 148), Gemini 2.5 Flash 140.8 (#97 of 148) and DeepSeek-V3.1 139.9 (#100 of 148). Their confidence ranges do not overlap (143.6–147.0 vs 138.5–142.3), so the gap is a real one.
Which is better for coding?
There are no published SWE-bench Verified results for DeepSeek-V3.1 and Gemini 2.5 Flash 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. All three support tool calling for agent workflows.
Which has the bigger context window?
Gemini 2.5 Flash has the largest context window at 1,048,576 tokens, against 400,000 for GPT-5 Mini and 131,072 for DeepSeek-V3.1. Maximum output per response: DeepSeek-V3.1 up to 8,192, Gemini 2.5 Flash up to 65,536, GPT-5 Mini up to 128,000 tokens.
Which can read images, PDFs, audio or video?
DeepSeek-V3.1 accepts text; Gemini 2.5 Flash accepts text, images, PDFs, audio and video; GPT-5 Mini accepts text and images. Gemini 2.5 Flash handles the widest range of inputs.
Are any of these open source?
DeepSeek-V3.1 publishes its weights (MIT License) and can be self-hosted; Gemini 2.5 Flash and GPT-5 Mini is proprietary.
Which is newer?
DeepSeek-V3.1 is the newest, released Aug 21, 2025. GPT-5 Mini came out Aug 7, 2025; Gemini 2.5 Flash came out Jun 17, 2025. Knowledge cutoff: Gemini 2.5 Flash Jan 2025, GPT-5 Mini May 30, 2024.
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 Oct 4, 2026.
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