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Comparison · 2 models · Updated Oct 4, 2026

Claude Sonnet 5.5 vs Muse Spark 1.3

Too close to call on our weighted score (Muse Spark 1.3 73, Claude Sonnet 5.5 72). The right pick depends on what you value most.

  1. Anthropic

    Claude Sonnet 5.5

    Released Sep 28, 2026

    72/100
    • ECI165.2
    • Price$2.00 / $10.00
    • Context1M
    Full specs Remove Claude Sonnet 5.5

  2. Meta

    Muse Spark 1.3

    Released Sep 2, 2026

    73/100
    • ECI156.9
    • Price$1.25 / $4.25
    • Context1.05M
    Full specs Remove Muse Spark 1.3

  3. Add a model

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01 — Verdict

Too close to call

It is close. Our weighted score puts them within 1 points (Muse Spark 1.3 73/100, Claude Sonnet 5.5 72/100), so choose by what matters most for your work: Claude Sonnet 5.5 for raw capability, Muse Spark 1.3 on price and Muse Spark 1.3 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Sonnet 5.5Capabilities Index (ECI): Claude Sonnet 5.5 165.2 · Muse Spark 1.3 156.9
  • Lowest priceMuse Spark 1.3Muse Spark 1.3 $2.00 · Claude Sonnet 5.5 $4.00 per 1M tokens (3:1 blend)
  • Longest contextMuse Spark 1.3Muse Spark 1.3 1,048,576 · Claude Sonnet 5.5 1,000,000 tokens
  • Widest inputsMuse Spark 1.3Claude Sonnet 5.5: 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
MeasureWeightClaude Sonnet 5.5Muse Spark 1.3
CapabilityCapabilities Index (ECI)50%9787
Price25%2136
Inputs & features15%80100
Context window10%6061
Overall100%72/10073/100
02 — Side by side

Every spec in one table

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

Claude Sonnet 5.5 vs Muse Spark 1.3 specifications side by side
SpecificationClaude Sonnet 5.5AnthropicMuse Spark 1.3Meta
Capability
Capabilities Index (ECI)165.2 (best)156.9
ECI rank#3 of 148 (best)#17 of 148
GPQA DiamondGraduate-level science questions95.6%—
FrontierMath Tiers 1–3Research-level mathematics88.8% (best)74.4%
OTIS Mock AIME 2024–2025Competition mathematics100% (best)99.2%
SimpleQA VerifiedShort factual questions46.5%—
Price per million tokens
Input$2.00$1.25 (best)
Output$10.00$4.25 (best)
Cached input$0.20$0.15 (best)
Blended (3:1)$4.00$2.00 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Anthropic APIOfficial Meta API
Limits
Context window1,000,000 tokens1,048,576 tokens (best)
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 IDclaude-sonnet-5-5muse-spark-1.3
API providers23 (best)12
ReleasedSep 28, 2026Sep 2, 2026
Knowledge cutoffJun 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.

  • Claude Sonnet 5.5$40.00
  • Muse Spark 1.3$21.00
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 5.5 or Muse Spark 1.3?

It is close. Our weighted score puts them within 1 points (Muse Spark 1.3 73/100, Claude Sonnet 5.5 72/100), so choose by what matters most for your work: Claude Sonnet 5.5 for raw capability, Muse Spark 1.3 on price and Muse Spark 1.3 for long inputs. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 5.5 or Muse Spark 1.3?

Muse Spark 1.3 is cheaper at $1.25 input / $4.25 output per million tokens (official Meta API price). Claude Sonnet 5.5 costs $2.00 input / $10.00 output per million tokens (official Anthropic API price). At a typical mix of three input tokens to one output token, that is $2.00 per million tokens for Muse Spark 1.3 versus $4.00 for Claude Sonnet 5.5 (2× as much).

Which scores higher on benchmarks?

Claude Sonnet 5.5 scores higher on the Capabilities Index (ECI): Claude Sonnet 5.5 165.2 (#3 of 148) and Muse Spark 1.3 156.9 (#17 of 148). Their confidence ranges do not overlap (161.8–169.4 vs 154.7–159.6), so the gap is a real one. On individual benchmarks: FrontierMath Tiers 1–3 — Claude Sonnet 5.5 88.8%, Muse Spark 1.3 74.4%; OTIS Mock AIME 2024–2025 — Claude Sonnet 5.5 100%, Muse Spark 1.3 99.2%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Sonnet 5.5 and Muse Spark 1.3 yet, so there is no like-for-like coding score. On overall capability, Claude Sonnet 5.5 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?

Muse Spark 1.3 has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 5.5. Maximum output per response: Claude Sonnet 5.5 up to 128,000, Muse Spark 1.3 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 5.5 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. Claude Sonnet 5.5 and Muse Spark 1.3 are proprietary and only available through APIs and apps.

Which is newer?

Claude Sonnet 5.5 is the newest, released Sep 28, 2026. Muse Spark 1.3 came out Sep 2, 2026. Knowledge cutoff: Claude Sonnet 5.5 Jun 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 Oct 4, 2026.

05 — Keep comparing

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