Solar Mini 4 vs Viv Fast
Viv Fast comes out ahead, 73 to 64 on our weighted score, though Solar Mini 4 is 11% cheaper per token.
UpstageSolar Mini 4
64/100- ECI—
- Price$0.10 / $0.40
- Context524K
- Our pick
VivgridViv Fast
73/100- ECI—
- Price$0.13 / $0.40
- Context1M
Add a model
Make it a three-way comparison.
Viv Fast is our pick
Viv Fast is the better all-round choice, scoring 73/100 against Solar Mini 4 (64). It leads on inputs & features and context window. Solar Mini 4 wins on price. 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 priceSolar Mini 4Solar Mini 4 $0.175 · Viv Fast $0.198 per 1M tokens (3:1 blend)
- Longest contextViv FastViv Fast 1,000,000 · Solar Mini 4 524,288 tokens
- Widest inputsViv FastSolar Mini 4: Text · Viv Fast: Text, Images
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Solar Mini 4 | Viv Fast |
|---|---|---|---|
| Price | 50% | 82 | 80 |
| Inputs & features | 30% | 45 | 70 |
| Context window | 20% | 49 | 60 |
| Overall | 100% | 64/100 | 73/100 |
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 | Solar Mini 4Upstage | Viv FastVivgrid |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.10 (best) | $0.13 |
| Output | $0.40 | $0.40 |
| Cached input | $0.01 (best) | $0.05 |
| Blended (3:1) | $0.175 (best) | $0.198 |
| Long-context rate | Same rate | Same rate |
| Price source | Official Upstage API | Official Vivgrid API |
| Limits | ||
| Context window | 524,288 tokens | 1,000,000 tokens (best) |
| Max output | 131,072 tokens | 256,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | No | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yesminimal · low · medium · high · xhigh · max | Yeslow · high · max |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | solar-mini4 | viv-fast |
| API providers | 4 (best) | 1 |
| Released | Sep 22, 2026 | Sep 21, 2026 |
| Knowledge cutoff | Feb 2026 | Sep 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Solar Mini 4$1.80
- Viv Fast$2.10
Which should you choose?
Which is better: Solar Mini 4 or Viv Fast?
Viv Fast is the better all-round choice, scoring 73/100 against Solar Mini 4 (64). It leads on inputs & features and context window. Solar Mini 4 wins on price. 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, Solar Mini 4 or Viv Fast?
Solar Mini 4 is cheaper at $0.10 input / $0.40 output per million tokens (official Upstage API price). Viv Fast costs $0.13 input / $0.40 output per million tokens (official Vivgrid API price). At a typical mix of three input tokens to one output token, that is $0.175 per million tokens for Solar Mini 4 versus $0.198 for Viv Fast (1.1× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Solar Mini 4 has not been scored yet and Viv Fast has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Solar Mini 4 and Viv Fast yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Viv Fast has the largest context window at 1,000,000 tokens, against 524,288 for Solar Mini 4. Maximum output per response: Solar Mini 4 up to 131,072, Viv Fast up to 256,000 tokens.
Which can read images, PDFs, audio or video?
Solar Mini 4 accepts text; Viv Fast accepts text and images. Viv Fast handles the widest range of inputs.
Are any of these open source?
No. Solar Mini 4 and Viv Fast are proprietary and only available through APIs and apps.
Which is newer?
Solar Mini 4 is the newest, released Sep 22, 2026. Viv Fast came out Sep 21, 2026. Knowledge cutoff: Solar Mini 4 Feb 2026, Viv Fast Sep 2026.
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.
