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Comparison · 2 models · Updated Nov 2, 2026

Muse Spark Open vs Claude Sonnet 5.5

Claude Sonnet 5.5 comes out ahead, 72 to 68 on our weighted score, though Muse Spark Open is 2× cheaper per token.

  1. Meta

    Muse Spark Open

    Released Oct 15, 2026New

    68/100
    • ECI155.1
    • Price$1.25 / $4.25
    • Context1.05M
    Full specs Remove Muse Spark Open
  2. Our pick

    Anthropic

    Claude Sonnet 5.5

    Released Sep 28, 2026New

    72/100
    • ECI166.7
    • Price$2.00 / $10.00
    • Context1M
    Full specs Remove Claude Sonnet 5.5

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Claude Sonnet 5.5 is our pick

Claude Sonnet 5.5 is the better all-round choice, scoring 72/100 against Muse Spark Open (68). It leads on capability. Muse Spark Open wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityClaude Sonnet 5.5Capabilities Index (ECI): Claude Sonnet 5.5 166.7 · Muse Spark Open 155.1
  • Lowest priceMuse Spark OpenMuse Spark Open $2.00 · Claude Sonnet 5.5 $4.00 per 1M tokens (3:1 blend)
  • Longest contextMuse Spark OpenMuse Spark Open 1,048,576 · Claude Sonnet 5.5 1,000,000 tokens
  • Widest inputsMuse Spark OpenMuse Spark Open: Text, Images, Audio, Video · Claude Sonnet 5.5: Text, Images, PDFs
  • Self-hostingMuse Spark OpenPublishes downloadable weights (Muse Model License)
How the score is built
MeasureWeightMuse Spark OpenClaude Sonnet 5.5
CapabilityCapabilities Index (ECI)50%8397
Price25%3420
Inputs & features15%8080
Context window10%6160
Overall100%68/10072/100
02 — Side by side

Every spec in one table

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

Muse Spark Open vs Claude Sonnet 5.5 specifications side by side
SpecificationMuse Spark OpenMetaClaude Sonnet 5.5Anthropic
Capability
Capabilities Index (ECI)155.1166.7 (best)
ECI rank#39 of 165#5 of 165 (best)
GPQA DiamondGraduate-level science questions88.6%95.6% (best)
FrontierMath Tiers 1–3Research-level mathematics69.8%88.8% (best)
OTIS Mock AIME 2024–2025Competition mathematics98.1%100% (best)
SimpleQA VerifiedShort factual questions56.6% (best)46.5%
Price per million tokens
Input$1.25 (best)$2.00
Output$4.25 (best)$10.00
Cached input—$0.10
Blended (3:1)$2.00 (best)$4.00
Long-context rateSame rateSame rate
Price sourceMedian of 16 providersOfficial Anthropic API
Limits
Context window1,048,576 tokens (best)1,000,000 tokens
Max output131,072 tokens (best)128,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoYes
AudioYesNo
VideoYesNo
ReasoningYesYeslow · medium · high · xhigh · max
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenMuse Model LicenseProprietary
API model ID—claude-sonnet-5-5
API providers1634 (best)
ReleasedOct 15, 2026Sep 28, 2026
Knowledge cutoffJan 4, 2026Jun 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.

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

Which should you choose?

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

Claude Sonnet 5.5 is the better all-round choice, scoring 72/100 against Muse Spark Open (68). It leads on capability. Muse Spark Open wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

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

Muse Spark Open is cheaper at $1.25 input / $4.25 output per million tokens (median across 16 API providers). 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 Open 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 5.5 166.7 (#5 of 165) and Muse Spark Open 155.1 (#39 of 165). Their confidence ranges do not overlap (163.6–171.3 vs 153.1–157.3), so the gap is a real one. On individual benchmarks: GPQA Diamond — Claude Sonnet 5.5 95.6%, Muse Spark Open 88.6%; FrontierMath Tiers 1–3 — Claude Sonnet 5.5 88.8%, Muse Spark Open 69.8%; OTIS Mock AIME 2024–2025 — Claude Sonnet 5.5 100%, Muse Spark Open 98.1%; SimpleQA Verified — Muse Spark Open 56.6%, Claude Sonnet 5.5 46.5%.

Which is better for coding?

There are no published SWE-bench Verified results for Muse Spark Open and Claude Sonnet 5.5 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 Open has the largest context window at 1,048,576 tokens, against 1,000,000 for Claude Sonnet 5.5. Maximum output per response: Muse Spark Open up to 131,072, Claude Sonnet 5.5 up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Muse Spark Open accepts text, images, audio and video; Claude Sonnet 5.5 accepts text, images and PDFs. Muse Spark Open handles the widest range of inputs.

Are any of these open source?

Muse Spark Open publishes its weights (Muse Model License) and can be self-hosted; Claude Sonnet 5.5 is proprietary.

Which is newer?

Muse Spark Open is the newest, released Oct 15, 2026. Claude Sonnet 5.5 came out Sep 28, 2026. Knowledge cutoff: Muse Spark Open Jan 4, 2026, 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 Nov 2, 2026.

05 — Keep comparing

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