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Claude Opus 5.5 vs Muse Spark 1.3

Claude Opus 5.5 and Muse Spark 1.3 are closely matched at 59.7 and 53.8 on the LLM Stats Score. Muse Spark 1.3 is 4.0x cheaper per token.

Anthropic · Meta · Updated for 2026

Which is better?

Claude Opus 5.5 and Muse Spark 1.3 are closely matched on the overall LLM Stats Score at 59.7 and 53.8.

In the 3 individual benchmarks reported for both models, Muse Spark 1.3 wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, Muse Spark 1.3 is roughly 4.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Muse Spark 1.3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 5.5

  • you want the most recent training data — it shipped Sep 2026

Choose Muse Spark 1.3

  • you value its reported benchmark strengths — it wins 2 of 3 exact shared results
  • cost matters — it's about 4.0x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Muse Spark 1.3
Meta
Core performance indexes
LLM Stats Score
59.7
#1
53.8
#8
Reasoning
57.8
#1
51.2
#10
Coding
51.7
#1
41.4
#11
Agents
44.5
#2
39.5
#7
Cost, coverage & limits
Benchmark wins
1 of 3
2 of 3
Input price
$4.00 / M
$1.25 / M
Output price
$20.00 / M
$4.25 / M
Context window
1,000,000
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
Muse Spark 1.3
Tool use
32.9#2
30.1#7
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 11 for Muse Spark 1.3

3 shared

Claude Opus 5.5 outperforms in 1 benchmarks (OSWorld 2.0), while Muse Spark 1.3 is better at 2 benchmarks (AutomationBench, DeepSWE 1.1).

Muse Spark 1.3 shows notably better performance in the majority of benchmarks.

Wed Sep 23 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Muse Spark 1.3 costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 3.2x more expensive than Muse Spark 1.3 ($1.25/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 4.7x more expensive than Muse Spark 1.3 ($4.25/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than Muse Spark 1.3.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Wed Sep 23 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
Meta
Muse Spark 1.3
Input tokens$1.25
Output tokens$4.25
Best providerMeta
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Muse Spark 1.3 accepts 1,048,576 input tokens compared to Claude Opus 5.5's 1,000,000 tokens. Muse Spark 1.3 can generate longer responses up to 943,718 tokens, while Claude Opus 5.5 is limited to 128,000 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Meta
Muse Spark 1.3
Input1,048,576 tokens
Output943,718 tokens
Wed Sep 23 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and Muse Spark 1.3 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 5.5

Text
Images
Audio
Video

Muse Spark 1.3

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 5.5

Proprietary

Closed source

Muse Spark 1.3

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Muse Spark 1.3 was released on 2026-09-02.

Claude Opus 5.5 is 1 month newer than Muse Spark 1.3.

Claude Opus 5.5

Sep 22, 2026

0 days ago

2w newer
Muse Spark 1.3

Sep 2, 2026

2 weeks ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while Muse Spark 1.3's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Muse Spark 1.3's cutoff date.

Claude Opus 5.5

Jun 2026

Muse Spark 1.3

—

Provider Availability

Claude Opus 5.5 is available from Anthropic. Muse Spark 1.3 is available from Meta Model API.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

Muse Spark 1.3

meta logo
Meta
Input Price:Input: $1.25/1MOutput Price:Output: $4.25/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Muse Spark 1.3 side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Muse Spark 1.3
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Muse Spark 1.3.

Which is better, Claude Opus 5.5 or Muse Spark 1.3?

Claude Opus 5.5 and Muse Spark 1.3 are closely matched on the LLM Stats Score at 59.7 and 53.8. Claude Opus 5.5 is made by Anthropic and Muse Spark 1.3 is made by Meta. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5.5 compare to Muse Spark 1.3 in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. Muse Spark 1.3 scores MRCR v2 (8-needle): 98.5%, MRCR v2 (8-needle, 512K-1M): 98.1%, DeepSearchQA: 89.4%, Terminal-Bench 2.1: 88.8%, DeepSWE 1.1: 75.4%.

Is Claude Opus 5.5 cheaper than Muse Spark 1.3?

Muse Spark 1.3 is 3.2x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Muse Spark 1.3 costs $1.25/M input and $4.25/M output via meta.

What are the context window sizes for Claude Opus 5.5 and Muse Spark 1.3?

Claude Opus 5.5 supports 1.0M tokens and Muse Spark 1.3 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 5.5 and Muse Spark 1.3?

Key differences include LLM Stats Score (59.7 vs 53.8), context window (1.0M vs 1.0M), input pricing ($4.00 vs $1.25/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Muse Spark 1.3?

Claude Opus 5.5 is developed by Anthropic and Muse Spark 1.3 is developed by Meta.

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