ZMIME
Comparison · 3 models · Updated Oct 4, 2026

GPT-5.6 Cyber vs MiMo-V2.5-Pro-UltraSpeed vs Seed 2.1 Pro

Seed 2.1 Pro comes out ahead, 50 to 43 and 30 on our weighted score, though MiMo-V2.5-Pro-UltraSpeed is 8% cheaper per token.

  1. OpenAI

    GPT-5.6 Cyber

    Released Aug 7, 2026

    30/100
    • ECI—
    • Price$12.50 / $75.00
    • Context400K
  2. Xiaomi

    MiMo-V2.5-Pro-UltraSpeed

    Released Jun 8, 2026Beta

    43/100
    • ECI—
    • Price$1.30 / $2.61
    • Context1.05M
  3. Our pick

    ByteDance Seed

    Seed 2.1 Pro

    Released Jun 23, 2026

    50/100
    • ECI—
    • Price$0.891 / $4.45
    • Context256K
01 — Verdict

Seed 2.1 Pro is our pick

Seed 2.1 Pro is the better all-round choice, scoring 50/100 against MiMo-V2.5-Pro-UltraSpeed (43) and GPT-5.6 Cyber (30). It leads on inputs & features. MiMo-V2.5-Pro-UltraSpeed wins 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 priceMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed $1.63 · Seed 2.1 Pro $1.78 · GPT-5.6 Cyber $28.13 per 1M tokens (3:1 blend)
  • Longest contextMiMo-V2.5-Pro-UltraSpeedMiMo-V2.5-Pro-UltraSpeed 1,048,576 · GPT-5.6 Cyber 400,000 · Seed 2.1 Pro 256,000 tokens
  • Widest inputsSeed 2.1 ProGPT-5.6 Cyber: Text, Images · MiMo-V2.5-Pro-UltraSpeed: Text · Seed 2.1 Pro: Text, Images, Video
  • Self-hostingMiMo-V2.5-Pro-UltraSpeedPublishes downloadable weights
How the score is built
MeasureWeightGPT-5.6 CyberMiMo-V2.5-Pro-UltraSpeedSeed 2.1 Pro
Price50%04038
Inputs & features30%703580
Context window20%446136
Overall100%30/10043/10050/100

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.

GPT-5.6 Cyber vs MiMo-V2.5-Pro-UltraSpeed vs Seed 2.1 Pro specifications side by side
SpecificationGPT-5.6 CyberOpenAIMiMo-V2.5-Pro-UltraSpeedXiaomiSeed 2.1 ProByteDance Seed
Capability
Capabilities Index (ECI)———
ECI rank———
Price per million tokens
Input$12.50$1.30$0.891 (best)
Output$75.00$2.61 (best)$4.45
Cached input$1.25$0.011 (best)$0.178
Blended (3:1)$28.13$1.63 (best)$1.78
Long-context rateSame rateSame rateSame rate
Price sourceOfficial OpenAI APIOfficial Xiaomi APIOfficial Volcengine Ark API
Limits
Context window400,000 tokens1,048,576 tokens (best)256,000 tokens
Max output128,000 tokens131,072 tokens256,000 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesNoYes
PDFsNoNoNo
AudioNoNoNo
VideoNoNoYes
ReasoningYeslow · medium · high · xhigh · maxYesYesminimal · low · medium · high · xhigh · max
Tool callingYesYesYes
Structured outputYesNoYes
Availability
WeightsProprietaryOpenProprietary
API model IDgpt-daybreak-red-latestmimo-v2.5-pro-ultraspeeddoubao-seed-2-1-pro-260628
API providers112 (best)
ReleasedAug 7, 2026Jun 8, 2026Jun 23, 2026
Knowledge cutoffFeb 16, 2026Dec 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.

  • GPT-5.6 Cyber$275.00
  • MiMo-V2.5-Pro-UltraSpeed$18.27
  • Seed 2.1 Pro$17.81
04 — Questions

Which should you choose?

Which is better: GPT-5.6 Cyber, MiMo-V2.5-Pro-UltraSpeed or Seed 2.1 Pro?

Seed 2.1 Pro is the better all-round choice, scoring 50/100 against MiMo-V2.5-Pro-UltraSpeed (43) and GPT-5.6 Cyber (30). It leads on inputs & features. MiMo-V2.5-Pro-UltraSpeed wins 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, GPT-5.6 Cyber, MiMo-V2.5-Pro-UltraSpeed or Seed 2.1 Pro?

MiMo-V2.5-Pro-UltraSpeed is cheaper at $1.30 input / $2.61 output per million tokens (official Xiaomi API price). Seed 2.1 Pro costs $0.891 input / $4.45 output per million tokens (official Volcengine Ark API price); GPT-5.6 Cyber costs $12.50 input / $75.00 output per million tokens (official OpenAI 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 2.1 Pro (1.1× as much) and $28.13 for GPT-5.6 Cyber (17× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers all three models yet. GPT-5.6 Cyber has not been scored yet, MiMo-V2.5-Pro-UltraSpeed has not been scored yet and Seed 2.1 Pro has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.6 Cyber, MiMo-V2.5-Pro-UltraSpeed and Seed 2.1 Pro 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 400,000 for GPT-5.6 Cyber and 256,000 for Seed 2.1 Pro. Maximum output per response: GPT-5.6 Cyber up to 128,000, MiMo-V2.5-Pro-UltraSpeed up to 131,072, Seed 2.1 Pro up to 256,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.6 Cyber accepts text and images; MiMo-V2.5-Pro-UltraSpeed accepts text; Seed 2.1 Pro accepts text, images and video. Seed 2.1 Pro 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; GPT-5.6 Cyber and Seed 2.1 Pro is proprietary.

Which is newer?

GPT-5.6 Cyber is the newest, released Aug 7, 2026. Seed 2.1 Pro came out Jun 23, 2026; MiMo-V2.5-Pro-UltraSpeed came out Jun 8, 2026. Knowledge cutoff: GPT-5.6 Cyber Feb 16, 2026, 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.