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Comparison · 2 models · Updated Oct 4, 2026

Seed 2.0 Code vs GPT-5.1 Codex mini

Too close to call on our weighted score (GPT-5.1 Codex mini 59, Seed 2.0 Code 57). The right pick depends on what you value most.

  1. ByteDance Seed

    Seed 2.0 Code

    Released Feb 14, 2026

    57/100
    • ECI—
    • Price$0.475 / $2.37
    • Context262K
  2. OpenAI

    GPT-5.1 Codex mini

    Released Nov 13, 2025

    59/100
    • ECI—
    • Price$0.25 / $2.00
    • Context400K
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01 — Verdict

Too close to call

It is close. Our weighted score puts them within 2 points (GPT-5.1 Codex mini 59/100, Seed 2.0 Code 57/100), so choose by what matters most for your work: GPT-5.1 Codex mini on price and GPT-5.1 Codex mini 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 priceGPT-5.1 Codex miniGPT-5.1 Codex mini $0.688 · Seed 2.0 Code $0.95 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.1 Codex miniGPT-5.1 Codex mini 400,000 · Seed 2.0 Code 262,144 tokens
  • Widest inputsSeed 2.0 CodeSeed 2.0 Code: Text, Images, Video · GPT-5.1 Codex mini: Text, Images
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightSeed 2.0 CodeGPT-5.1 Codex mini
Price50%5158
Inputs & features30%8070
Context window20%3744
Overall100%57/10059/100

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 2.0 Code vs GPT-5.1 Codex mini specifications side by side
SpecificationSeed 2.0 CodeByteDance SeedGPT-5.1 Codex miniOpenAI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.475$0.25 (best)
Output$2.37$2.00 (best)
Cached input$0.095—
Blended (3:1)$0.95$0.688 (best)
Long-context rateOver 32K: $0.712 / $3.56Same rate
Price sourceOfficial Volcengine Ark APIMedian of 10 providers
Limits
Context window262,144 tokens400,000 tokens (best)
Max output131,072 tokens (best)128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoYesNo
ReasoningYesminimal · low · medium · high · xhigh · maxYes
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDdoubao-seed-2-0-code-preview-260215—
API providers1010
ReleasedFeb 14, 2026Nov 13, 2025
Knowledge cutoff—Sep 30, 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 2.0 Code$9.50
  • GPT-5.1 Codex mini$6.50
04 — Questions

Which should you choose?

Which is better: Seed 2.0 Code or GPT-5.1 Codex mini?

It is close. Our weighted score puts them within 2 points (GPT-5.1 Codex mini 59/100, Seed 2.0 Code 57/100), so choose by what matters most for your work: GPT-5.1 Codex mini on price and GPT-5.1 Codex mini 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 2.0 Code or GPT-5.1 Codex mini?

GPT-5.1 Codex mini is cheaper at $0.25 input / $2.00 output per million tokens (median across 10 API providers). Seed 2.0 Code costs $0.475 input / $2.37 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $0.688 per million tokens for GPT-5.1 Codex mini versus $0.95 for Seed 2.0 Code (1.4× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Seed 2.0 Code has not been scored yet and GPT-5.1 Codex mini has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Seed 2.0 Code and GPT-5.1 Codex mini 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?

GPT-5.1 Codex mini has the largest context window at 400,000 tokens, against 262,144 for Seed 2.0 Code. Maximum output per response: Seed 2.0 Code up to 131,072, GPT-5.1 Codex mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Seed 2.0 Code accepts text, images and video; GPT-5.1 Codex mini accepts text and images. Seed 2.0 Code handles the widest range of inputs.

Are any of these open source?

No. Seed 2.0 Code and GPT-5.1 Codex mini are proprietary and only available through APIs and apps.

Which is newer?

Seed 2.0 Code is the newest, released Feb 14, 2026. GPT-5.1 Codex mini came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 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.