Model Comparison

GPT-4.5 vs Muse Spark 1.1Which is better in 2026?

Muse Spark 1.1 significantly outperforms across most benchmarks. Muse Spark 1.1 is 46.9x cheaper per token.

Verdict: GPT-4.5 vs Muse Spark 1.1 — which is better?

GPT-4.5 (by OpenAI) and Muse Spark 1.1 (by Meta) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

GPT-4.5 outperforms in 0 benchmarks, while Muse Spark 1.1 is better at 1 benchmark (CharXiv-R). Muse Spark 1.1 significantly outperforms across most benchmarks.

On price, Muse Spark 1.1 is roughly 46.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Muse Spark 1.1 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose GPT-4.5 if…

  • you want predictable pricing at $75.00/M input and $150.00/M output

Choose Muse Spark 1.1 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • cost matters — it's about 46.9x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT-4.5 outperforms in 0 benchmarks, while Muse Spark 1.1 is better at 1 benchmark (CharXiv-R).

Muse Spark 1.1 significantly outperforms across most benchmarks.

Sat Jul 18 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Muse Spark 1.1 costs less

For input processing, GPT-4.5 ($75.00/1M tokens) is 60.0x more expensive than Muse Spark 1.1 ($1.25/1M tokens).

For output processing, GPT-4.5 ($150.00/1M tokens) is 35.3x more expensive than Muse Spark 1.1 ($4.25/1M tokens).

In conclusion, GPT-4.5 is more expensive than Muse Spark 1.1.*

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

Lowest available price from all providers
Sat Jul 18 2026 • llm-stats.com
OpenAI
GPT-4.5
Input tokens$75.00
Output tokens$150.00
Best providerOpenAI
Meta
Muse Spark 1.1
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 1.1 accepts 1,048,576 input tokens compared to GPT-4.5's 128,000 tokens. Muse Spark 1.1 can generate longer responses up to 131,072 tokens, while GPT-4.5 is limited to 4,096 tokens.

OpenAI
GPT-4.5
Input128,000 tokens
Output4,096 tokens
Meta
Muse Spark 1.1
Input1,048,576 tokens
Output131,072 tokens
Sat Jul 18 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-4.5 and Muse Spark 1.1 support multimodal inputs.

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

GPT-4.5

Text
Images
Audio
Video

Muse Spark 1.1

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.

GPT-4.5

Proprietary

Closed source

Muse Spark 1.1

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4.5 was released on 2025-02-27, while Muse Spark 1.1 was released on 2026-07-09.

Muse Spark 1.1 is 17 months newer than GPT-4.5.

GPT-4.5

Feb 27, 2025

1.4 years ago

Muse Spark 1.1

Jul 9, 2026

1 weeks ago

1.4yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

GPT-4.5 is available from OpenAI. Muse Spark 1.1 is available from Meta Model API.

GPT-4.5

openai logo
OpenAI
Input Price:Input: $75.00/1MOutput Price:Output: $150.00/1M

Muse Spark 1.1

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→

Key Takeaways

OpenAI

No standout differentiators in the data we have for this pair.

Meta
Larger context window (1,048,576 tokens)
Less expensive input tokens
Less expensive output tokens
Higher CharXiv-R score (88.4% vs 55.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-4.5 and Muse Spark 1.1 side-by-side, then vote on the output you prefer.

GPT-4.5
✓ Preferred
Muse Spark 1.1
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-4.5
Meta
Muse Spark 1.1

FAQ

Common questions about GPT-4.5 vs Muse Spark 1.1.

Which is better, GPT-4.5 or Muse Spark 1.1?

Muse Spark 1.1 significantly outperforms across most benchmarks. GPT-4.5 is made by OpenAI and Muse Spark 1.1 is made by Meta. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-4.5 compare to Muse Spark 1.1 in benchmarks?

GPT-4.5 scores GSM8k: 97.0%, MMLU: 90.8%, CharXiv-D: 90.0%, IFEval: 88.2%, HumanEval: 88.0%. Muse Spark 1.1 scores CharXiv-R: 88.4%, MCP Atlas: 88.1%, OSWorld-Verified: 80.8%, Terminal-Bench 2.1: 80.0%, BabyVision: 76.3%.

Is GPT-4.5 cheaper than Muse Spark 1.1?

Muse Spark 1.1 is 60.0x cheaper for input tokens. GPT-4.5 costs $75.00/M input and $150.00/M output via openai. Muse Spark 1.1 costs $1.25/M input and $4.25/M output via meta.

What are the context window sizes for GPT-4.5 and Muse Spark 1.1?

GPT-4.5 supports 128K tokens and Muse Spark 1.1 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 GPT-4.5 and Muse Spark 1.1?

Key differences include context window (128K vs 1.0M), input pricing ($75.00 vs $1.25/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-4.5 and Muse Spark 1.1?

GPT-4.5 is developed by OpenAI and Muse Spark 1.1 is developed by Meta.

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