GPT-5.6 Luna vs Muse Spark 1.2
GPT-5.6 Luna and Muse Spark 1.2 are closely matched at 46.5 and 41.1 on the LLM Stats Score. Muse Spark 1.2 is 3.6x cheaper per token.
OpenAI · Meta · Updated for 2026
Which is better?
GPT-5.6 Luna and Muse Spark 1.2 are closely matched on the overall LLM Stats Score at 46.5 and 41.1.
In the 2 individual benchmarks reported for both models, GPT-5.6 Luna wins 2; this is a narrower head-to-head signal than the composite indexes.
On price, Muse Spark 1.2 is roughly 3.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Luna also accepts a larger context window (1,050,000 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 GPT-5.6 Luna
- you value its reported benchmark strengths — it wins 2 of 2 exact shared results
- you process long inputs — it offers a 1,050,000 token context window
Choose Muse Spark 1.2
- cost matters — it's about 3.6x cheaper per token
- you want the most recent training data — it shipped Aug 2026
At a glance
The differences that matter most.
Individual benchmarks
44 reported for GPT-5.6 Luna · 3 for Muse Spark 1.2
GPT-5.6 Luna outperforms in 2 benchmarks (DeepSWE 1.1, Terminal-Bench 2.1), while Muse Spark 1.2 is better at 0 benchmarks.
GPT-5.6 Luna significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Luna ($0.20/1M tokens) is 2.0x more expensive than Muse Spark 1.2 ($0.10/1M tokens).
For output processing, GPT-5.6 Luna ($1.20/1M tokens) is 6.0x more expensive than Muse Spark 1.2 ($0.20/1M tokens).
In conclusion, GPT-5.6 Luna is more expensive than Muse Spark 1.2.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Luna accepts 1,050,000 input tokens compared to Muse Spark 1.2's 1,048,576 tokens. Muse Spark 1.2 can generate longer responses up to 131,072 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5.6 Luna and Muse Spark 1.2 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Luna
Muse Spark 1.2
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5.6 Luna was released on 2026-07-09, while Muse Spark 1.2 was released on 2026-08-05.
Muse Spark 1.2 is 1 month newer than GPT-5.6 Luna.
Jul 9, 2026
1 months ago
Aug 5, 2026
3 weeks ago
3w newerKnowledge Cutoff
When training data ends
GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Muse Spark 1.2's cutoff date is not specified.
We can confirm GPT-5.6 Luna's training data extends to 2026-02-16, but cannot make a direct comparison without Muse Spark 1.2's cutoff date.
Feb 2026
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Provider Availability
GPT-5.6 Luna is available from OpenAI. Muse Spark 1.2 is available from Meta Model API.
GPT-5.6 Luna
Muse Spark 1.2
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Luna and Muse Spark 1.2 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Luna vs Muse Spark 1.2.