Standard Compute
Model Comparison 2026

GPT-5.4 vs GPT-5.6 Luna

GPT-5.4
OpenAI · Balanced · Proprietary
$6.25/1M · 1.1M ctx
GPT-5.6 Luna
OpenAI · Budget · Proprietary
$1.25/1M · 1.1M ctx

Community Vote

Pick a winner in each dimension — change your vote anytime. 5 votes cast so far.

Output Quality
Correctness and depth of what it produces
GPT-5.4 33%67% Luna
Agentic Ability
Tool calls, instruction-following, and multi-step tasks
Speed
Tokens per second and time-to-first-token
Value for $
How much capability you get per dollar
GPT-5.4 0%100% Luna
Reliability
Consistent results — fewer refusals, loops, and format breaks
GPT-5.4 0%100% Luna

Specs & Pricing, Side by Side

Spec
GPT-5.4
Luna
Maker
OpenAI
OpenAI
Blended price / 1M
$6.25
$1.25
Input / output
$2.50 in · $15 out / 1M tokens
$0.50 in · $3.00 out / 1M tokens
Context window
1.1M
1.1M
Open weights
No
No
Tool use
Yes
Yes
Reasoning
Yes
Yes
Output Quality
9.2
8.4
Agentic Ability
9.1
8.3
Speed
7.6
9.3
Value for $
8.1
9.0
Reliability
8.6
9.1

Pricing and capabilities synced from the OpenRouter catalogue. Scores are editorial (0–10).

Verdict: GPT-5.4 or Luna?

Updated 2026-08-02

Choose GPT-5.4 if you want the OpenAI daily driver — strong and well-priced. Choose GPT-5.6 Luna if you want cheap, fast subtasks, routing, and subagents in OpenAI-based stacks.

In our editorial scoring, GPT-5.6 Luna leads in 3 of five dimensions (speed, value for $ and reliability), while GPT-5.4 leads in 2. On price, GPT-5.4 runs about $6.25 per 1M tokens (blended) and is proprietary; GPT-5.6 Luna is about $1.25 and proprietary.

Across 5 community votes on this matchup, GPT-5.6 Luna currently leads in 3 of five dimensions. Cast your own vote above to move the needle.

Where GPT-5.4 falls short
  • A notch below 5.5 on the hardest tasks
  • Still pricier than open models
Full GPT-5.4 breakdown →
Where Luna falls short
  • Clear quality step below Terra and Sol
  • Very new — behavior under long agent chains still settling
Full Luna breakdown →

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