ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Gemini 3.8 Flash vs Solar Pro 4

Gemini 3.8 Flash comes out ahead, 63 to 55 on our weighted score, though Solar Pro 4 is 2.9× cheaper per token.

  1. Our pick

    Google

    Gemini 3.8 Flash

    Released Sep 2, 2026

    63/100
    • ECI156.9
    • Price$0.75 / $3.75
    • Context1.05M
    Full specs Remove Gemini 3.8 Flash

  2. Upstage

    Solar Pro 4

    Released Aug 6, 2026

    55/100
    • ECI—
    • Price$0.30 / $1.20
    • Context524K
    Full specs Remove Solar Pro 4

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Gemini 3.8 Flash is our pick

Gemini 3.8 Flash is the better all-round choice, scoring 63/100 against Solar Pro 4 (55). It leads on inputs & features and context window. Solar Pro 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 Pro 4Solar Pro 4 $0.525 · Gemini 3.8 Flash $1.50 per 1M tokens (3:1 blend)
  • Longest contextGemini 3.8 FlashGemini 3.8 Flash 1,048,576 · Solar Pro 4 524,288 tokens
  • Widest inputsGemini 3.8 FlashGemini 3.8 Flash: Text, Images, PDFs, Audio, Video · Solar Pro 4: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGemini 3.8 FlashSolar Pro 4
Price50%4263
Inputs & features30%10045
Context window20%6149
Overall100%63/10055/100

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.

Gemini 3.8 Flash vs Solar Pro 4 specifications side by side
SpecificationGemini 3.8 FlashGoogleSolar Pro 4Upstage
Capability
Capabilities Index (ECI)156.9—
ECI rank#15 of 148—
GPQA DiamondGraduate-level science questions95.4%—
FrontierMath Tiers 1–3Research-level mathematics68.4%—
OTIS Mock AIME 2024–2025Competition mathematics98.9%—
SimpleQA VerifiedShort factual questions69.7%—
Price per million tokens
Input$0.75$0.30 (best)
Output$3.75$1.20 (best)
Cached input$0.075$0.06 (best)
Blended (3:1)$1.50$0.525 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Google APIOfficial Upstage API
Limits
Context window1,048,576 tokens (best)524,288 tokens
Max output65,536 tokens131,072 tokens (best)
Inputs and features
TextYesYes
ImagesYesNo
PDFsYesNo
AudioYesNo
VideoYesNo
ReasoningYeslow · medium · highYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgemini-3.8-flashsolar-pro4
API providers21 (best)3
ReleasedSep 2, 2026Aug 6, 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.

  • Gemini 3.8 Flash$15.00
  • Solar Pro 4$5.40
04 — Questions

Which should you choose?

Which is better: Gemini 3.8 Flash or Solar Pro 4?

Gemini 3.8 Flash is the better all-round choice, scoring 63/100 against Solar Pro 4 (55). It leads on inputs & features and context window. Solar Pro 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, Gemini 3.8 Flash or Solar Pro 4?

Solar Pro 4 is cheaper at $0.30 input / $1.20 output per million tokens (official Upstage API price). Gemini 3.8 Flash costs $0.75 input / $3.75 output per million tokens (official Google API price). At a typical mix of three input tokens to one output token, that is $0.525 per million tokens for Solar Pro 4 versus $1.50 for Gemini 3.8 Flash (2.9× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Gemini 3.8 Flash has an ECI of 156.9 and Solar Pro 4 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Gemini 3.8 Flash and Solar Pro 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?

Gemini 3.8 Flash has the largest context window at 1,048,576 tokens, against 524,288 for Solar Pro 4. Maximum output per response: Gemini 3.8 Flash up to 65,536, Solar Pro 4 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Gemini 3.8 Flash accepts text, images, PDFs, audio and video; Solar Pro 4 accepts text. Gemini 3.8 Flash handles the widest range of inputs.

Are any of these open source?

No. Gemini 3.8 Flash and Solar Pro 4 are proprietary and only available through APIs and apps.

Which is newer?

Gemini 3.8 Flash is the newest, released Sep 2, 2026. Solar Pro 4 came out Aug 6, 2026. Knowledge cutoff: Solar Pro 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 Oct 4, 2026.

05 — Keep comparing

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