ZMIME
Comparison · 2 models · Updated Nov 2, 2026

Mercury 2.5 vs Solar Mini 4

Solar Mini 4 comes out ahead, 64 to 55 on our weighted score, and it is the cheaper option too.

  1. Inception

    Mercury 2.5

    Released Sep 8, 2026New

    55/100
    • ECI—
    • Price$0.20 / $0.75
    • Context260K
  2. Our pick

    Upstage

    Solar Mini 4

    Released Sep 22, 2026New

    64/100
    • ECI—
    • Price$0.10 / $0.40
    • Context524K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Solar Mini 4 is our pick

Solar Mini 4 is the better all-round choice, scoring 64/100 against Mercury 2.5 (55). It leads on price 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 priceSolar Mini 4Solar Mini 4 $0.175 · Mercury 2.5 $0.338 per 1M tokens (3:1 blend)
  • Longest contextSolar Mini 4Solar Mini 4 524,288 · Mercury 2.5 260,000 tokens
  • Widest inputsSame inputsMercury 2.5: Text · Solar Mini 4: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightMercury 2.5Solar Mini 4
Price50%6982
Inputs & features30%4545
Context window20%3649
Overall100%55/10064/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Mercury 2.5 vs Solar Mini 4 specifications side by side
SpecificationMercury 2.5InceptionSolar Mini 4Upstage
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.20$0.10 (best)
Output$0.75$0.40 (best)
Cached input$0.02$0.01 (best)
Blended (3:1)$0.338$0.175 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Inception APIOfficial Upstage API
Limits
Context window260,000 tokens524,288 tokens (best)
Max output65,536 tokens131,072 tokens (best)
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYeslow · medium · highYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDmercury-2.5solar-mini4
API providers6 (best)4
ReleasedSep 8, 2026Sep 22, 2026
Knowledge cutoff—Feb 2026
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Mercury 2.5$3.50
  • Solar Mini 4$1.80
04 — Questions

Which should you choose?

Which is better: Mercury 2.5 or Solar Mini 4?

Solar Mini 4 is the better all-round choice, scoring 64/100 against Mercury 2.5 (55). It leads on price 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, Mercury 2.5 or Solar Mini 4?

Solar Mini 4 is cheaper at $0.10 input / $0.40 output per million tokens (official Upstage API price). Mercury 2.5 costs $0.20 input / $0.75 output per million tokens (official Inception 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 $0.338 for Mercury 2.5 (1.9× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Mercury 2.5 has not been scored yet and Solar Mini 4 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Mercury 2.5 and Solar Mini 4 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?

Solar Mini 4 has the largest context window at 524,288 tokens, against 260,000 for Mercury 2.5. Maximum output per response: Mercury 2.5 up to 65,536, Solar Mini 4 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Mercury 2.5 accepts text; Solar Mini 4 accepts text. They handle the same number of input types.

Are any of these open source?

No. Mercury 2.5 and Solar Mini 4 are proprietary and only available through APIs and apps.

Which is newer?

Solar Mini 4 is the newest, released Sep 22, 2026. Mercury 2.5 came out Sep 8, 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.