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Head-to-head comparison

Muse Spark 1.3 vs GPT-5.5

Muse Spark 1.3 (Meta) and GPT-5.5 (OpenAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 3 September 2026

As of 3 September 2026, Muse Spark 1.3 holds the stronger ModelCap Index position (#4 vs #9); and Muse Spark 1.3 is 7.1× cheaper per output token ($4.25/1M vs $30.00/1M).

Which should you choose?

Choose Muse Spark 1.3 if…

  • you want the stronger overall ModelCap Index position — #4 against #9 (81.7 vs 77.9 points).
  • API cost matters — $4.25/1M output tokens against $30.00/1M, about 7.1× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.25/1M against $5.00/1M.
  • AA Intelligence Index is your yardstick — 62.1 against 56.3.
  • you want the more recently listed model — Muse Spark 1.3 was listed 2 September 2026, GPT-5.5 24 April 2026.

Choose GPT-5.5 if…

  • you want provider choice — 3 listed API providers against 1.

Muse Spark 1.3 vs GPT-5.5: specs, pricing and context

Specification comparison of Muse Spark 1.3 and GPT-5.5
FieldMuse Spark 1.3MetaGPT-5.5OpenAI
ModelCap Index position#4#9
Index score81.777.9
EvidenceMeasuredMeasured
Input price / 1M tokens$1.25$5.00
Output price / 1M tokens$4.25$30.00
Context window1M tokens1M tokens
Max output tokens944K128K
API providers listed13
Weight accessAPI onlyAPI only
Input modalitiesText, Image, Video, File, AudioFile, Image, Text
First listed2 September 202624 April 2026
PublisherMetaOpenAI

Evidence: 1 public benchmark observation across 1 board · 7 public benchmark observations across 7 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Muse Spark 1.3 vs GPT-5.5

Public benchmark boards where Muse Spark 1.3 or GPT-5.5 has a published result
BoardMuse Spark 1.3GPT-5.5Leads
Arena codingArena (LMArena)—15201514–1526HighOnly one result
LMArena AgentLMArena—7.9%6.8%–9.0%X-HighOnly one result
ARC-AGI-2ARC Prize Foundation—85.0%X-HighOnly one result
ARC-AGI-3ARC Prize Foundation—0.4%HighOnly one result
AA Intelligence IndexArtificial Analysis62.1intelligence-index56.3intelligence-indexMuse Spark 1.3
AA Terminal-Bench 2.1Artificial Analysis—84.3%terminal-bench-2.1Only one result
AA τ²-Bench TelecomArtificial Analysis—93.9%tau2-bench-telecomOnly one result
AA Humanity's Last ExamArtificial Analysis—45.8%humanitys-last-examOnly one result
WildClawBench OpenClawWildClawBench—58.2Only one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Muse Spark 1.3 vs GPT-5.5: common questions

Is Muse Spark 1.3 better than GPT-5.5?

Muse Spark 1.3 ranks higher on the ModelCap Index as of 3 September 2026: #4 against #9. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Muse Spark 1.3 cheaper than GPT-5.5?

Muse Spark 1.3 is cheaper on output tokens: $4.25/1M against $30.00/1M. Input tokens are $1.25/1M for Muse Spark 1.3 and $5.00/1M for GPT-5.5. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, Muse Spark 1.3 or GPT-5.5?

Both publish a 1M-token context window.

Which is better for coding, Muse Spark 1.3 or GPT-5.5?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are Muse Spark 1.3 and GPT-5.5 open-weight models?

Muse Spark 1.3: API only. GPT-5.5: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Muse Spark 1.3 and GPT-5.5?

ModelCap currently lists 1 API provider for Muse Spark 1.3 and 3 for GPT-5.5, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Muse Spark 1.3 vs GPT-5.5 comparison?

Every figure comes from the sealed ModelCap dataset published 3 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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