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Comparison · 2 models · Updated Nov 2, 2026

GPT-6.1 Terra vs Muse Spark 1.3

GPT-6.1 Terra comes out ahead, 76 to 72 on our weighted score.

  1. Our pick

    OpenAI

    GPT-6.1 Terra

    Released Oct 26, 2026New

    76/100
    • ECI168.1
    • Price$1.00 / $5.00
    • Context1.05M
    Full specs Remove GPT-6.1 Terra

  2. Meta

    Muse Spark 1.3

    Released Sep 2, 2026

    72/100
    • ECI157.4
    • Price$1.25 / $4.25
    • Context1.05M
    Full specs Remove Muse Spark 1.3

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-6.1 Terra is our pick

GPT-6.1 Terra is the better all-round choice, scoring 76/100 against Muse Spark 1.3 (72). It leads on capability. Muse Spark 1.3 wins on inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGPT-6.1 TerraCapabilities Index (ECI): GPT-6.1 Terra 168.1 · Muse Spark 1.3 157.4
  • Lowest priceSame priceGPT-6.1 Terra $2.00 · Muse Spark 1.3 $2.00 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameGPT-6.1 Terra 1,050,000 · Muse Spark 1.3 1,048,576 tokens
  • Widest inputsMuse Spark 1.3GPT-6.1 Terra: Text, Images, PDFs · Muse Spark 1.3: Text, Images, PDFs, Audio, Video
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightGPT-6.1 TerraMuse Spark 1.3
CapabilityCapabilities Index (ECI)50%9986
Price25%3434
Inputs & features15%80100
Context window10%6161
Overall100%76/10072/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

GPT-6.1 Terra vs Muse Spark 1.3 specifications side by side
SpecificationGPT-6.1 TerraOpenAIMuse Spark 1.3Meta
Capability
Capabilities Index (ECI)168.1 (best)157.4
ECI rank#3 of 165 (best)#24 of 165
GPQA DiamondGraduate-level science questions94.3%—
FrontierMath Tiers 1–3Research-level mathematics90.9% (best)74.4%
OTIS Mock AIME 2024–2025Competition mathematics100% (best)99.2%
SimpleQA VerifiedShort factual questions57.3%—
Price per million tokens
Input$1.00 (best)$1.25
Output$5.00$4.25 (best)
Cached input$0.05 (best)$0.15
Blended (3:1)$2.00$2.00
Long-context rateOver 272K: $2.00 / $7.50Same rate
Price sourceOfficial OpenAI APIOfficial Meta API
Limits
Context window1,050,000 tokens (best)1,048,576 tokens
Max output128,000 tokens131,072 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsYesYes
AudioNoYes
VideoNoYes
ReasoningYeslow · medium · high · xhigh · maxYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDgpt-6.1-terramuse-spark-1.3
API providers22 (best)17
ReleasedOct 26, 2026Sep 2, 2026
Knowledge cutoffJun 1, 2026—
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-6.1 Terra$20.00
  • Muse Spark 1.3$21.00
04 — Questions

Which should you choose?

Which is better: GPT-6.1 Terra or Muse Spark 1.3?

GPT-6.1 Terra is the better all-round choice, scoring 76/100 against Muse Spark 1.3 (72). It leads on capability. Muse Spark 1.3 wins on inputs & features. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, GPT-6.1 Terra or Muse Spark 1.3?

GPT-6.1 Terra and Muse Spark 1.3 cost the same: $1.00 input / $5.00 output per million tokens.

Which scores higher on benchmarks?

GPT-6.1 Terra scores higher on the Capabilities Index (ECI): GPT-6.1 Terra 168.1 (#3 of 165) and Muse Spark 1.3 157.4 (#24 of 165). Their confidence ranges do not overlap (164.9–172.9 vs 155.4–159.9), so the gap is a real one. On individual benchmarks: FrontierMath Tiers 1–3 — GPT-6.1 Terra 90.9%, Muse Spark 1.3 74.4%; OTIS Mock AIME 2024–2025 — GPT-6.1 Terra 100%, Muse Spark 1.3 99.2%.

Which is better for coding?

There are no published SWE-bench Verified results for GPT-6.1 Terra and Muse Spark 1.3 yet, so there is no like-for-like coding score. On overall capability, GPT-6.1 Terra leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Their context windows are effectively the same size: GPT-6.1 Terra 1,050,000 and Muse Spark 1.3 1,048,576 tokens. Maximum output per response: GPT-6.1 Terra up to 128,000, Muse Spark 1.3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

GPT-6.1 Terra accepts text, images and PDFs; Muse Spark 1.3 accepts text, images, PDFs, audio and video. Muse Spark 1.3 handles the widest range of inputs.

Are any of these open source?

No. GPT-6.1 Terra and Muse Spark 1.3 are proprietary and only available through APIs and apps.

Which is newer?

GPT-6.1 Terra is the newest, released Oct 26, 2026. Muse Spark 1.3 came out Sep 2, 2026. Knowledge cutoff: GPT-6.1 Terra Jun 1, 2026.

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 Nov 2, 2026.

05 — Keep comparing

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