Gemini 2.5 Flash-Lite vs o4-mini-deep-research vs Solar Pro 2
Gemini 2.5 Flash-Lite comes out ahead, 83 to 51 and 37 on our weighted score, and it is the cheaper option too.
- Our pick
GoogleGemini 2.5 Flash-Lite
83/100- ECI—
- Price$0.10 / $0.40
- Context1.05M
OpenAIo4-mini-deep-research
37/100- ECI—
- Price$1.80 / $7.20
- Context200K
UpstageSolar Pro 2
51/100- ECI—
- Price$0.25 / $0.25
- Context66K
Gemini 2.5 Flash-Lite is our pick
Gemini 2.5 Flash-Lite is the better all-round choice, scoring 83/100 against Solar Pro 2 (51) and o4-mini-deep-research (37). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceGemini 2.5 Flash-LiteGemini 2.5 Flash-Lite $0.175 · Solar Pro 2 $0.25 · o4-mini-deep-research $3.15 per 1M tokens (3:1 blend)
- Longest contextGemini 2.5 Flash-LiteGemini 2.5 Flash-Lite 1,048,576 · o4-mini-deep-research 200,000 · Solar Pro 2 65,536 tokens
- Widest inputsGemini 2.5 Flash-LiteGemini 2.5 Flash-Lite: Text, Images, PDFs, Audio, Video · o4-mini-deep-research: Text, Images · Solar Pro 2: Text
- Self-hostingNo open weightsAll three are available only through APIs
| Measure | Weight | Gemini 2.5 Flash-Lite | o4-mini-deep-research | Solar Pro 2 |
|---|---|---|---|---|
| Price | 50% | 82 | 25 | 75 |
| Inputs & features | 30% | 100 | 60 | 35 |
| Context window | 20% | 61 | 32 | 12 |
| Overall | 100% | 83/100 | 37/100 | 51/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Gemini 2.5 Flash-LiteGoogle | o4-mini-deep-researchOpenAI | Solar Pro 2Upstage |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $0.10 (best) | $1.80 | $0.25 |
| Output | $0.40 | $7.20 | $0.25 (best) |
| Cached input | $0.01 | — | — |
| Blended (3:1) | $0.175 (best) | $3.15 | $0.25 |
| Long-context rate | Same rate | Same rate | Same rate |
| Price source | Official Google API | Median of 1 providers | Official Upstage API |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 200,000 tokens | 65,536 tokens |
| Max output | 65,536 tokens | 100,000 tokens (best) | 8,192 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | No |
| PDFs | Yes | No | No |
| Audio | Yes | No | No |
| Video | Yes | No | No |
| Reasoning | Yes | Yes | Yesminimal · high |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | No | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Proprietary |
| API model ID | gemini-2.5-flash-lite | — | solar-pro2 |
| API providers | 24 (best) | 1 | 2 |
| Released | Jun 17, 2025 | Jun 26, 2025 | May 20, 2025 |
| Knowledge cutoff | Jan 2025 | May 2024 | Mar 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Gemini 2.5 Flash-Lite$1.80
- o4-mini-deep-research$32.40
- Solar Pro 2$3.00
Which should you choose?
Which is better: Gemini 2.5 Flash-Lite, o4-mini-deep-research or Solar Pro 2?
Gemini 2.5 Flash-Lite is the better all-round choice, scoring 83/100 against Solar Pro 2 (51) and o4-mini-deep-research (37). It leads on price, inputs & features and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Gemini 2.5 Flash-Lite, o4-mini-deep-research or Solar Pro 2?
Gemini 2.5 Flash-Lite is cheaper at $0.10 input / $0.40 output per million tokens (official Google API price). Solar Pro 2 costs $0.25 input / $0.25 output per million tokens (official Upstage API price); o4-mini-deep-research costs $1.80 input / $7.20 output per million tokens (median across 1 API provider). At a typical mix of three input tokens to one output token, that is $0.175 per million tokens for Gemini 2.5 Flash-Lite versus $0.25 for Solar Pro 2 (1.4× as much) and $3.15 for o4-mini-deep-research (18× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. Gemini 2.5 Flash-Lite has not been scored yet, o4-mini-deep-research has not been scored yet and Solar Pro 2 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Gemini 2.5 Flash-Lite, o4-mini-deep-research and Solar Pro 2 yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Gemini 2.5 Flash-Lite has the largest context window at 1,048,576 tokens, against 200,000 for o4-mini-deep-research and 65,536 for Solar Pro 2. Maximum output per response: Gemini 2.5 Flash-Lite up to 65,536, o4-mini-deep-research up to 100,000, Solar Pro 2 up to 8,192 tokens.
Which can read images, PDFs, audio or video?
Gemini 2.5 Flash-Lite accepts text, images, PDFs, audio and video; o4-mini-deep-research accepts text and images; Solar Pro 2 accepts text. Gemini 2.5 Flash-Lite handles the widest range of inputs.
Are any of these open source?
No. Gemini 2.5 Flash-Lite, o4-mini-deep-research and Solar Pro 2 are proprietary and only available through APIs and apps.
Which is newer?
o4-mini-deep-research is the newest, released Jun 26, 2025. Gemini 2.5 Flash-Lite came out Jun 17, 2025; Solar Pro 2 came out May 20, 2025. Knowledge cutoff: Gemini 2.5 Flash-Lite Jan 2025, o4-mini-deep-research May 2024, Solar Pro 2 Mar 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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