ZMIME
Comparison · 3 models · Updated Oct 4, 2026

Seed Evolving vs Seed 2.1 Pro vs MiMo-V2.5-Pro-UltraSpeed

Too close to call on our weighted score (Seed Evolving 50, Seed 2.1 Pro 50, MiMo-V2.5-Pro-UltraSpeed 43). The right pick depends on what you value most.

  1. ByteDance Seed

    Seed Evolving

    Released Jun 23, 2026

    50/100
    • ECI—
    • Price$0.891 / $4.45
    • Context256K
  2. ByteDance Seed

    Seed 2.1 Pro

    Released Jun 23, 2026

    50/100
    • ECI—
    • Price$0.891 / $4.45
    • Context256K
  3. Xiaomi

    MiMo-V2.5-Pro-UltraSpeed

    Released Jun 8, 2026Beta

    43/100
    • ECI—
    • Price$1.30 / $2.61
    • Context1.05M
01 — Verdict

Too close to call

It is close. Our weighted score puts them within a point (Seed Evolving 50/100, Seed 2.1 Pro 50/100, MiMo-V2.5-Pro-UltraSpeed 43/100), so choose by what matters most for your work: MiMo-V2.5-Pro-UltraSpeed on price and MiMo-V2.5-Pro-UltraSpeed for long inputs. 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 priceMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed $1.63 · Seed Evolving $1.78 · Seed 2.1 Pro $1.78 per 1M tokens (3:1 blend)
  • Longest contextMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed 1,048,576 · Seed Evolving 256,000 · Seed 2.1 Pro 256,000 tokens
  • Widest inputsSeed Evolving and Seed 2.1 ProSeed Evolving: Text, Images, Video · Seed 2.1 Pro: Text, Images, Video · MiMo-V2.5-Pro-UltraSpeed: Text
  • Self-hostingMiMo-V2.5-Pro-UltraSpeedPublishes downloadable weights
How the score is built
MeasureWeightSeed EvolvingSeed 2.1 ProMiMo-V2.5-Pro-UltraSpeed
Price50%383840
Inputs & features30%808035
Context window20%363661
Overall100%50/10050/10043/100

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.

Seed Evolving vs Seed 2.1 Pro vs MiMo-V2.5-Pro-UltraSpeed specifications side by side
SpecificationSeed EvolvingByteDance SeedSeed 2.1 ProByteDance SeedMiMo-V2.5-Pro-UltraSpeedXiaomi
Capability
Capabilities Index (ECI)———
ECI rank———
Price per million tokens
Input$0.891 (best)$0.891 (best)$1.30
Output$4.45$4.45$2.61 (best)
Cached input$0.178$0.178$0.011 (best)
Blended (3:1)$1.78$1.78$1.63 (best)
Long-context rateSame rateSame rateSame rate
Price sourceOfficial Volcengine Ark APIOfficial Volcengine Ark APIOfficial Xiaomi API
Limits
Context window256,000 tokens256,000 tokens1,048,576 tokens (best)
Max output256,000 tokens (best)256,000 tokens (best)131,072 tokens
Inputs and features
TextYesYesYes
ImagesYesYesNo
PDFsNoNoNo
AudioNoNoNo
VideoYesYesNo
ReasoningYesminimal · low · medium · high · xhigh · maxYesminimal · low · medium · high · xhigh · maxYes
Tool callingYesYesYes
Structured outputYesYesNo
Availability
WeightsProprietaryProprietaryOpen
API model IDdoubao-seed-evolvingdoubao-seed-2-1-pro-260628mimo-v2.5-pro-ultraspeed
API providers2 (best)2 (best)1
ReleasedJun 23, 2026Jun 23, 2026Jun 8, 2026
Knowledge cutoff——Dec 2024
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.

  • Seed Evolving$17.81
  • Seed 2.1 Pro$17.81
  • MiMo-V2.5-Pro-UltraSpeed$18.27
04 — Questions

Which should you choose?

Which is better: Seed Evolving, Seed 2.1 Pro or MiMo-V2.5-Pro-UltraSpeed?

It is close. Our weighted score puts them within a point (Seed Evolving 50/100, Seed 2.1 Pro 50/100, MiMo-V2.5-Pro-UltraSpeed 43/100), so choose by what matters most for your work: MiMo-V2.5-Pro-UltraSpeed on price and MiMo-V2.5-Pro-UltraSpeed for long inputs. 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, Seed Evolving, Seed 2.1 Pro or MiMo-V2.5-Pro-UltraSpeed?

MiMo-V2.5-Pro-UltraSpeed is cheaper at $1.30 input / $2.61 output per million tokens (official Xiaomi API price). Seed Evolving costs $0.891 input / $4.45 output per million tokens (official Volcengine Ark API price); Seed 2.1 Pro costs $0.891 input / $4.45 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $1.63 per million tokens for MiMo-V2.5-Pro-UltraSpeed versus $1.78 for Seed Evolving (1.1× as much) and $1.78 for Seed 2.1 Pro (1.1× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers all three models yet. Seed Evolving has not been scored yet, Seed 2.1 Pro has not been scored yet and MiMo-V2.5-Pro-UltraSpeed has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Seed Evolving, Seed 2.1 Pro and MiMo-V2.5-Pro-UltraSpeed 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-Pro-UltraSpeed has the largest context window at 1,048,576 tokens, against 256,000 for Seed Evolving and 256,000 for Seed 2.1 Pro. Maximum output per response: Seed Evolving up to 256,000, Seed 2.1 Pro up to 256,000, MiMo-V2.5-Pro-UltraSpeed up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Seed Evolving accepts text, images and video; Seed 2.1 Pro accepts text, images and video; MiMo-V2.5-Pro-UltraSpeed accepts text. Seed Evolving handles the widest range of inputs.

Are any of these open source?

MiMo-V2.5-Pro-UltraSpeed publishes its weights and can be self-hosted; Seed Evolving and Seed 2.1 Pro is proprietary.

Which is newer?

Seed Evolving is the newest, released Jun 23, 2026. Seed 2.1 Pro came out Jun 23, 2026; MiMo-V2.5-Pro-UltraSpeed came out Jun 8, 2026. Knowledge cutoff: MiMo-V2.5-Pro-UltraSpeed Dec 2024.

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.