GPT-5.6 Luna vs Muse Spark 1.3: Specs & Benchmark Comparison

CharacteristicGPT-5.6 LunaMuse Spark 1.3
CompanyOpenAIMeta
Release DateJuly 9, 2026September 2, 2026
Parameters
MultimodalYesYes
Context (input)1.1M1.0M
Context (output)128K944K
Input Price / 1M$0.20$0.10
Output Price / 1M$1.20$0.20
Average Score0.50.7
Benchmarks
MRCR v2 (8-needle)0.41.0
MRCR v2 (8-needle, 512K-1M)0.41.0
AutomationBench0.10.5
OSWorld 2.00.50.7
DeepSWE 1.10.70.8
Terminal-Bench 2.10.80.9

Visual Benchmark Comparison

GPT-5.6 Luna
Muse Spark 1.3
MRCR v2 (8-needle)0.4 vs 1.0
0.4
1.0
MRCR v2 (8-needle, 512K-1M)0.4 vs 1.0
0.4
1.0
AutomationBench0.1 vs 0.5
0.1
0.5
OSWorld 2.00.5 vs 0.7
0.5
0.7
DeepSWE 1.10.7 vs 0.8
0.7
0.8
Terminal-Bench 2.10.8 vs 0.9
0.8
0.9

Verdict

Muse Spark 1.3 leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5.6 Luna — 0.5, Muse Spark 1.3 — 0.7.

API Cost

Muse Spark 1.3 is 4.7x cheaper: input $0.10/1M vs $0.20/1M tokens.

Context Window

GPT-5.6 Luna supports a larger context: 1M vs 1M tokens.

Recency

Muse Spark 1.3 is newer: released 9/2/2026 vs 7/9/2026.

More About These Models

Related Comparisons

Frequently Asked Questions

Which is better for coding — GPT-5.6 Luna or Muse Spark 1.3?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GPT-5.6 Luna or Muse Spark 1.3?
Muse Spark 1.3 is cheaper for input: $0.10 per 1M tokens vs $0.20.
Which has a larger context window — GPT-5.6 Luna or Muse Spark 1.3?
GPT-5.6 Luna supports a larger context: 1,050,000 tokens vs 1,048,576.

The GPT-5.6 Luna and Muse Spark 1.3 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.6 Luna or Muse Spark 1.3 page. See also the complete list of AI model comparisons.