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Comparison · 3 models · Updated Oct 4, 2026

MiMo-V2.5 vs MiMo-V2-Pro vs Step 3.5 Flash 2603

MiMo-V2.5 comes out ahead, 79 to 62 and 54 on our weighted score, though Step 3.5 Flash 2603 is 14% cheaper per token.

  1. Our pick

    Xiaomi

    MiMo-V2.5

    Released Apr 22, 2026

    79/100
    • ECI—
    • Price$0.14 / $0.28
    • Context1.05M
  2. Xiaomi

    MiMo-V2-Pro

    Released Mar 18, 2026Deprecated

    54/100
    • ECI—
    • Price$0.435 / $0.87
    • Context1.05M
  3. StepFun

    Step 3.5 Flash 2603

    Released Apr 2, 2026

    62/100
    • ECI—
    • Price$0.10 / $0.30
    • Context256K
01 — Verdict

MiMo-V2.5 is our pick

MiMo-V2.5 is the better all-round choice, scoring 79/100 against Step 3.5 Flash 2603 (62) and MiMo-V2-Pro (54). It leads on inputs & features. Step 3.5 Flash 2603 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 priceStep 3.5 Flash 2603Step 3.5 Flash 2603 $0.15 · MiMo-V2.5 $0.175 · MiMo-V2-Pro $0.544 per 1M tokens (3:1 blend)
  • Longest contextMiMo-V2.5 and MiMo-V2-ProMiMo-V2.5 1,048,576 · MiMo-V2-Pro 1,048,576 · Step 3.5 Flash 2603 256,000 tokens
  • Widest inputsMiMo-V2.5MiMo-V2.5: Text, Images, Audio, Video · MiMo-V2-Pro: Text · Step 3.5 Flash 2603: Text
  • Self-hostingMiMo-V2.5 and Step 3.5 Flash 2603Publishes downloadable weights
How the score is built
MeasureWeightMiMo-V2.5MiMo-V2-ProStep 3.5 Flash 2603
Price50%866289
Inputs & features30%803535
Context window20%616136
Overall100%79/10054/10062/100

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.

MiMo-V2.5 vs MiMo-V2-Pro vs Step 3.5 Flash 2603 specifications side by side
SpecificationMiMo-V2.5XiaomiMiMo-V2-ProXiaomiStep 3.5 Flash 2603StepFun
Capability
Capabilities Index (ECI)———
ECI rank———
Price per million tokens
Input$0.14$0.435$0.10 (best)
Output$0.28 (best)$0.87$0.30
Cached input$0.0028 (best)$0.0036$0.02
Blended (3:1)$0.175$0.544$0.15 (best)
Long-context rateSame rateSame rateSame rate
Price sourceOfficial Xiaomi APIOfficial Xiaomi APIOfficial StepFun (Global) API
Limits
Context window1,048,576 tokens (best)1,048,576 tokens (best)256,000 tokens
Max output131,072 tokens131,072 tokens256,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesNoNo
PDFsNoNoNo
AudioYesNoNo
VideoYesNoNo
ReasoningYesYesYeslow · high
Tool callingYesYesYes
Structured outputNoNoNo
Availability
WeightsOpenProprietaryOpen
API model IDmimo-v2.5mimo-v2-prostep-3.5-flash-2603
API providers21 (best)43
ReleasedApr 22, 2026Mar 18, 2026Apr 2, 2026
Knowledge cutoffDec 2024Dec 2024Jan 2025
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.

  • MiMo-V2.5$1.96
  • MiMo-V2-Pro$6.09
  • Step 3.5 Flash 2603$1.60
04 — Questions

Which should you choose?

Which is better: MiMo-V2.5, MiMo-V2-Pro or Step 3.5 Flash 2603?

MiMo-V2.5 is the better all-round choice, scoring 79/100 against Step 3.5 Flash 2603 (62) and MiMo-V2-Pro (54). It leads on inputs & features. Step 3.5 Flash 2603 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, MiMo-V2.5, MiMo-V2-Pro or Step 3.5 Flash 2603?

Step 3.5 Flash 2603 is cheaper at $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). MiMo-V2.5 costs $0.14 input / $0.28 output per million tokens (official Xiaomi API price); MiMo-V2-Pro costs $0.435 input / $0.87 output per million tokens (official Xiaomi API price). At a typical mix of three input tokens to one output token, that is $0.15 per million tokens for Step 3.5 Flash 2603 versus $0.175 for MiMo-V2.5 (1.2× as much) and $0.544 for MiMo-V2-Pro (3.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers all three models yet. MiMo-V2.5 has not been scored yet, MiMo-V2-Pro has not been scored yet and Step 3.5 Flash 2603 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for MiMo-V2.5, MiMo-V2-Pro and Step 3.5 Flash 2603 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?

MiMo-V2.5 and MiMo-V2-Pro have the largest context windows (1,048,576 and 1,048,576 tokens), against 256,000 for Step 3.5 Flash 2603. Maximum output per response: MiMo-V2.5 up to 131,072, MiMo-V2-Pro up to 131,072, Step 3.5 Flash 2603 up to 256,000 tokens.

Which can read images, PDFs, audio or video?

MiMo-V2.5 accepts text, images, audio and video; MiMo-V2-Pro accepts text; Step 3.5 Flash 2603 accepts text. MiMo-V2.5 handles the widest range of inputs.

Are any of these open source?

MiMo-V2.5 and Step 3.5 Flash 2603 publishes its weights and can be self-hosted; MiMo-V2-Pro is proprietary.

Which is newer?

MiMo-V2.5 is the newest, released Apr 22, 2026. Step 3.5 Flash 2603 came out Apr 2, 2026; MiMo-V2-Pro came out Mar 18, 2026. Knowledge cutoff: MiMo-V2.5 Dec 2024, MiMo-V2-Pro Dec 2024, Step 3.5 Flash 2603 Jan 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 Oct 4, 2026.