AI Models · Paid vs Paid

Gemini 3.5 Flash Paid vs GPT-5.6 Luna Paid

Gemini 3.5 Flash vs GPT-5.6 Luna compared — price per token, context window, multimodality, openness and which to choose. Full 2026 breakdown.

Gemini 3.5 Flash — full profile ›  ·  GPT-5.6 Luna — full profile ›

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Choose GPT-5.6 Luna for the lower output price ($3/M vs $9/M). It also gives you the larger 1.1M context window.

Gemini 3.5 Flash vs GPT-5.6 Luna specs

SpecGemini 3.5 FlashGPT-5.6 Luna
MakerGoogleOpenAI
TypeProprietaryProprietary
Context window1M tokens1.1M tokens
Input price$1.5/M$0.5/M
Output price$9/M$3/M
Vision / multimodalYesYes
Tool / function callingYesYes
Self-hostableNo (API only)No (API only)
LicenseProprietaryProprietary

Feature comparison

CapabilityGemini 3.5 FlashGPT-5.6 Luna
Open weights (downloadable)✗✗
Self-hostable✗✗
Runs fully offline✗✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Gemini 3.5 Flash vs GPT-5.6 Luna

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Gemini 3.5 Flash
GPT-5.6 Luna
Intelligence index
50.2
51.2
Coding index
70.1
71.4
GPQA
92.2%
91.1%
Humanity's Last Exam
41%
37.2%
Long Context Reasoning
69.3%
74%
SciCode
53.1%
52.5%
IFBench
76.3%
–
τ²-Bench
95.3%
–
τ-Bench Banking
25.4%
27.2%
Terminal-Bench
78.7%
80.9%
Terminal-Bench Hard
40.9%
–
Speed
243 tok/s
202.4 tok/s
Latency
13.71s
73.7s
Intelligence per $
14.9
22.8

Benchmark data by Artificial Analysis.

How Gemini 3.5 Flash and GPT-5.6 Luna score

🤝 Neck and neck on these criteria (3.2 vs 3.3 / 5).
CriterionGemini 3.5 FlashGPT-5.6 Luna
Cost-efficiency3.54.0
Context window5.05.0
Openness1.51.5
Self-hosting1.01.0
Multimodality5.05.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Gemini 3.5 Flash Paid

Google · Proprietary

Gemini 3.5 Flash is Google's high-efficiency multimodal model, bringing near-Pro level coding and reasoning at Flash-tier cost and speed. It is highly optimized for coding proficiency and parallel agentic execution...

GPT-5.6 Luna Paid

OpenAI · Proprietary

GPT-5.6 Luna is a fast, cost-efficient model in OpenAI's GPT-5.6 series. It is suited for high-volume, latency-sensitive tasks such as chat, classification, and lightweight agentic workflows, providing capable reasoning for...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Gemini 3.5 Flash (batch)Gemini 3.6 FlashGemini 3.6 Flash (batch)Gemini 3 Flash PreviewGemini 3 Flash Preview (batch)Gemini 2.5 FlashGemini 2.5 Flash (batch)Google Gemini Flash LatestNano Banana 2 (Gemini 3.1 Flash Image)Nano Banana (Gemini 2.5 Flash Image)

Frequently asked questions

Gemini 3.5 Flash vs GPT-5.6 Luna — which is cheaper?

GPT-5.6 Luna is cheaper on output ($3/M vs $9/M).

Which has the larger context window?

GPT-5.6 Luna offers the larger context window (1.1M tokens).

Gemini 3.5 Flash vs GPT-5.6 Luna — which should I pick in 2026?

Choose GPT-5.6 Luna for the lower output price ($3/M vs $9/M). It also gives you the larger 1.1M context window.

People also compare

MiMo-V2.5-Pro vs Gemini 3.5 FlashMiMo-V2.5-Pro vs GPT-5.6 LunaDeepSeek V4 Pro vs Gemini 3.5 FlashDeepSeek V4 Pro vs GPT-5.6 LunaHy3 vs Gemini 3.5 FlashHy3 vs GPT-5.6 Luna

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →