OpenAI GPT-5.4 VS OpenAI GPT-5.6 Luna

✍️ Analysis by:the whichllmmodel Editorial Team|📅 Updated: June 2026

Decision Recommendation

⚖️ Editorial Verdict: In our analysis, GPT-5.6 Luna is the premium intelligence choice, scoring 5.0% higher on coding benchmarks. It also maintains strong cost efficiency. If you are building high-volume, simple chatbots or processing massive amounts of text where budget is critical, GPT-5.4 offers excellent cost savings. For agentic reasoning, code refactoring, or complex logical tasks, the accuracy premium of GPT-5.6 Luna fully justifies the cost.

Was this recommendation helpful?

Model Specs

GPT-5.4

Benchmarks & Scores

Coding (swe-bench-pro)

57.7%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)Winner (+0.5%)

92.8%

graduate-level science QA

Cost & Performance

Cost (per 1M tokens)

$5.63Input: $2.50 | Output: $15.00

Context Window

1.05M tokens

Model Specs

GPT-5.6 Luna

Benchmarks & Scores

Coding (swe-bench-pro)Winner (+5.0%)

62.7%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)

92.3%

graduate-level science QA

Cost & Performance

Cost (per 1M tokens)2.5x cheaper

$2.25Input: $1.00 | Output: $6.00

Context Window

1.05M tokens

Read our data collection methodology

Frequently Asked Questions about GPT-5.4 vs GPT-5.6 Luna comparison

GPT-5.6 Luna is cheaper than GPT-5.4. GPT-5.6 Luna has a blended cost of $2.25/1M tokens, which is about 2.5x cheaper than GPT-5.4 at $5.63/1M tokens.

GPT-5.6 Luna is better for coding tasks on this benchmark. It scores 62.7% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) compared to GPT-5.4 which scores 57.7%.

Related Matchups

Explore similar comparisons for GPT-5.4 and GPT-5.6 Luna.

Browse More Comparisons