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GPT-5.4 Mini vs GPT-5.6 Luna

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

GPT-5.6 Luna wins outright — it scores higher and costs less.

GPT-5.6 Luna leads by 7.2 points overall while listing 3.8× cheaper per blended million tokens. There is no trade-off to reason about here; the only reason to pick the other is a constraint this table does not show, like an existing contract, a region, or a provider you are already on. GPT-5.6 Luna also leads on measured cost per point of capability, at $0.0911 per point.

openai

GPT-5.4 Mini

Blended / 1M
$1.69
Context
400K
Released
Mar 17, 2026
Overall score
66.4
reasoningtool callingfile inputimage inputprompt caching

openai

GPT-5.6 Luna

Blended / 1M
$0.450
Context
1.1M
Released
Jul 9, 2026
Overall score
73.6
reasoningtool callingfile inputimage inputprompt caching

Specs and pricing

MetricGPT-5.4 MiniGPT-5.6 Luna
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

66.473.6win
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.1871$0.0911win
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$1.69$0.450win
Input price / 1M$0.750$0.200win
Output price / 1M$4.50$1.20win
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$0.075$0.020win
Context window400K1.1Mwin
Max output tokens128K128K

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — GPT-5.4 Mini on top, GPT-5.6 Luna below, both out of 100.

Agentic coding
41.7
48.4
Coding
71.6
82.9
Reasoning
71.3
85.6
Mathematics
78.5
87.2
Data analysis
70.8
78.0
Language
71.0
72.6
Instruction followingtoo close to call
59.8
60.1

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadGPT-5.4 MiniGPT-5.6 Luna
Support chatbot

1.2K in / 400 out × 200K requests

$491.40/mo$131.04/mo
RAG assistant

8K in / 600 out × 100K requests

$600.00/mo$160.00/mo
Coding agent

40K in / 4K out × 20K requests

$582.00/mo$155.20/mo
Document extraction

20K in / 1.5K out × 50K requests

$1053.75/mo$281.00/mo
Bulk classification

500 in / 20 out × 5M requests

$1987.50/mo$530.00/mo
Run these two through the cost calculator

Which should you pick?

You are running this at volume

GPT-5.6 Luna

Lowest measured cost per point of capability at $0.0911 per point — the gap compounds with every request.

Quality matters more than the bill

GPT-5.6 Luna

Highest overall LiveBench score of the two at 73.6.

The workload is coding or agentic work

GPT-5.6 Luna

Leads on agentic coding — 48.4 against 41.7.

You need to fit large documents in one call

GPT-5.6 Luna

Wider context window — 1.1M against 400K.

GPT-5.4 Mini vs GPT-5.6 Luna FAQ

Which is better, GPT-5.4 Mini or GPT-5.6 Luna?

GPT-5.6 Luna wins outright — it scores higher and costs less. GPT-5.6 Luna leads by 7.2 points overall while listing 3.8× cheaper per blended million tokens. There is no trade-off to reason about here; the only reason to pick the other is a constraint this table does not show, like an existing contract, a region, or a provider you are already on. GPT-5.6 Luna also leads on measured cost per point of capability, at $0.0911 per point.

Is GPT-5.4 Mini cheaper than GPT-5.6 Luna?

GPT-5.6 Luna is cheaper. On a 3:1 input:output blend, GPT-5.4 Mini lists at $1.69 per million tokens and GPT-5.6 Luna at $0.450 — GPT-5.6 Luna is 3.8× cheaper. Input and output are priced separately — GPT-5.4 Mini charges $0.750 in and $4.50 out, GPT-5.6 Luna charges $0.200 and $1.20 — so the model that looks cheaper flips depending on how output-heavy your workload is.

GPT-5.4 Mini vs GPT-5.6 Luna: which scores higher on benchmarks?

GPT-5.4 Mini scores 66.4 and GPT-5.6 Luna scores 73.6 overall on LiveBench, the mean of its seven categories. That is a 7.2-point lead for GPT-5.6 Luna. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.

Which gives better value for money, GPT-5.4 Mini or GPT-5.6 Luna?

GPT-5.6 Luna. Cost per point divides the measured dollars LiveBench spent running the benchmark by the score it earned, so it captures something token pricing misses: a reasoning model can emit many times more tokens than its per-token rate suggests. GPT-5.4 Mini works out at $0.1871 per point and GPT-5.6 Luna at $0.0911.

Does GPT-5.4 Mini or GPT-5.6 Luna have a bigger context window?

GPT-5.6 Luna has the larger context window: 400K for GPT-5.4 Mini against 1.1M for GPT-5.6 Luna. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.

Do GPT-5.4 Mini and GPT-5.6 Luna support prompt caching?

Both publish a cached-input rate: $0.075 per million for GPT-5.4 Mini and $0.020 for GPT-5.6 Luna, against full input rates of $0.750 and $0.200. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.