Solar Mini 4 vs Mercury 3
Mercury 3 comes out ahead, 67 to 64 on our weighted score, and it is the cheaper option too.
UpstageSolar Mini 4
64/100- ECI—
- Price$0.10 / $0.40
- Context524K
- Our pick
InceptionMercury 3
67/100- ECI—
- Price$0.10 / $0.35
- Context1M
Add a model
Make it a three-way comparison.
Mercury 3 is our pick
Mercury 3 is the better all-round choice, scoring 67/100 against Solar Mini 4 (64). It leads on 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 priceMercury 3Mercury 3 $0.163 · Solar Mini 4 $0.175 per 1M tokens (3:1 blend)
- Longest contextMercury 3Mercury 3 1,000,000 · Solar Mini 4 524,288 tokens
- Widest inputsSame inputsSolar Mini 4: Text · Mercury 3: Text
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Solar Mini 4 | Mercury 3 |
|---|---|---|---|
| Price | 50% | 82 | 84 |
| Inputs & features | 30% | 45 | 45 |
| Context window | 20% | 49 | 60 |
| Overall | 100% | 64/100 | 67/100 |
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 | Mercury 3Inception |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.10 | $0.10 |
| Output | $0.40 | $0.35 (best) |
| Cached input | $0.01 | $0.01 |
| Blended (3:1) | $0.175 | $0.163 (best) |
| Long-context rate | Same rate | Same rate |
| Price source | Official Upstage API | Official Inception API |
| Limits | ||
| Context window | 524,288 tokens | 1,000,000 tokens (best) |
| Max output | 131,072 tokens | 131,072 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | No | No |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yesminimal · low · medium · high · xhigh · max | Yeslow · medium · high |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | solar-mini4 | mercury-3 |
| API providers | 4 (best) | 3 |
| Released | Sep 22, 2026 | Oct 16, 2026 |
| Knowledge cutoff | Feb 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
- Mercury 3$1.70
Which should you choose?
Which is better: Solar Mini 4 or Mercury 3?
Mercury 3 is the better all-round choice, scoring 67/100 against Solar Mini 4 (64). It leads on 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, Solar Mini 4 or Mercury 3?
Mercury 3 is cheaper at $0.10 input / $0.35 output per million tokens (official Inception API price). Solar Mini 4 costs $0.10 input / $0.40 output per million tokens (official Upstage API price). At a typical mix of three input tokens to one output token, that is $0.163 per million tokens for Mercury 3 versus $0.175 for Solar Mini 4 (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 Mercury 3 has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Solar Mini 4 and Mercury 3 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?
Mercury 3 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, Mercury 3 up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Solar Mini 4 accepts text; Mercury 3 accepts text. They handle the same number of input types.
Are any of these open source?
No. Solar Mini 4 and Mercury 3 are proprietary and only available through APIs and apps.
Which is newer?
Mercury 3 is the newest, released Oct 16, 2026. Solar Mini 4 came out Sep 22, 2026. Knowledge cutoff: Solar Mini 4 Feb 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.
