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Comparison · 2 models · Updated Oct 4, 2026

GPT-5.1 Chat vs Seed 1.6

Seed 1.6 comes out ahead, 55 to 38 on our weighted score, and it is the cheaper option too.

  1. OpenAI

    GPT-5.1 Chat

    Released Nov 13, 2025

    38/100
    • ECI—
    • Price$1.25 / $10.00
    • Context128K
    Full specs Remove GPT-5.1 Chat
  2. Our pick

    ByteDance Seed

    Seed 1.6

    Released Oct 15, 2025

    55/100
    • ECI—
    • Price$0.119 / $1.19
    • Context256K
    Full specs Remove Seed 1.6

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Seed 1.6 is our pick

Seed 1.6 is the better all-round choice, scoring 55/100 against GPT-5.1 Chat (38). It leads on price and context window. GPT-5.1 Chat wins on inputs & features. 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 priceSeed 1.6Seed 1.6 $0.386 · GPT-5.1 Chat $3.44 per 1M tokens (3:1 blend)
  • Longest contextSeed 1.6Seed 1.6 256,000 · GPT-5.1 Chat 128,000 tokens
  • Widest inputsGPT-5.1 ChatGPT-5.1 Chat: Text, Images · Seed 1.6: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-5.1 ChatSeed 1.6
Price50%2469
Inputs & features30%7045
Context window20%2436
Overall100%38/10055/100

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.

GPT-5.1 Chat vs Seed 1.6 specifications side by side
SpecificationGPT-5.1 ChatOpenAISeed 1.6ByteDance Seed
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$1.25$0.119 (best)
Output$10.00$1.19 (best)
Cached input—$0.024
Blended (3:1)$3.44$0.386 (best)
Long-context rateSame rateOver 32K: $0.178 / $2.37
Price sourceMedian of 2 providersOfficial Volcengine Ark API
Limits
Context window128,000 tokens256,000 tokens (best)
Max output16,384 tokens64,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYesminimal · low · medium · high
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model ID—doubao-seed-1-6-251015
API providers22
ReleasedNov 13, 2025Oct 15, 2025
Knowledge cutoffSep 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.

  • GPT-5.1 Chat$32.50
  • Seed 1.6$3.56
04 — Questions

Which should you choose?

Which is better: GPT-5.1 Chat or Seed 1.6?

Seed 1.6 is the better all-round choice, scoring 55/100 against GPT-5.1 Chat (38). It leads on price and context window. GPT-5.1 Chat wins on inputs & features. 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-5.1 Chat or Seed 1.6?

Seed 1.6 is cheaper at $0.119 input / $1.19 output per million tokens (official Volcengine Ark API price). GPT-5.1 Chat costs $1.25 input / $10.00 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $0.386 per million tokens for Seed 1.6 versus $3.44 for GPT-5.1 Chat (8.9× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. GPT-5.1 Chat has not been scored yet and Seed 1.6 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-5.1 Chat and Seed 1.6 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?

Seed 1.6 has the largest context window at 256,000 tokens, against 128,000 for GPT-5.1 Chat. Maximum output per response: GPT-5.1 Chat up to 16,384, Seed 1.6 up to 64,000 tokens.

Which can read images, PDFs, audio or video?

GPT-5.1 Chat accepts text and images; Seed 1.6 accepts text. GPT-5.1 Chat handles the widest range of inputs.

Are any of these open source?

No. GPT-5.1 Chat and Seed 1.6 are proprietary and only available through APIs and apps.

Which is newer?

GPT-5.1 Chat is the newest, released Nov 13, 2025. Seed 1.6 came out Oct 15, 2025. Knowledge cutoff: GPT-5.1 Chat 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.

05 — Keep comparing

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