Model comparison · Updated 17 Aug 2026

Gemini 3.1 Flash Lite vs GPT-5.6 Luna

GPT-5.6 Luna is about 1.3× cheaper on input ($0.20 against $0.25 per 1M tokens) and on output. GPT-5.6 Luna has the larger context window (1.05M against 1.05M tokens). For a support chatbot at 10,000 chats a day, the standard-tier bill is about $248 a month for Gemini 3.1 Flash Lite and $198 for GPT-5.6 Luna.

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ModelsAtlas. “Gemini 3.1 Flash Lite vs GPT-5.6 Luna”. Retrieved 17 Aug 2026. https://modelsatlas.com/compare/google/gemini-3-1-flash/vs/openai/gpt-5-6-luna

Model A

Gemini 3.1 Flash Lite

by Google · weights not marked open · GRIDC5

Input / 1M
$0.25
observed We measured
Source
Our catalogue
Retrieved
17 Aug 2026

Output / 1M$1.50

Context1.05M

Model B

GPT-5.6 Luna

by OpenAI · weights not marked open · GRIDC6

Input / 1M
$0.20
observed We measured
Source
Our catalogue
Retrieved
17 Aug 2026

Output / 1M$1.20

Context1.05M

Key numbers

Standard tier · highlighted = better

Gemini 3.1 Flash Lite

GPT-5.6 Luna

Input / 1M tokens

$0.25

$0.20

Output / 1M tokens

$1.50

$1.20

Batch input / output

$0.13 / $0.75

$0.10 / $0.60

Context window

1,048,576

1,050,000

Input types

Not disclosed

Weights

Not marked open

Tiers listed

batch, standard

Prices checked

2026-08-17

What it costs for real workloads

Monthly, standard tier, 30 days

Support chatbot10k chats/day · 1.5k in, 300 out

$248/mo

$198/mo

RAG over documents2k queries/day · 12k in, 500 out

$225/mo

$180/mo

Coding agent300 tasks/day · 60k in, 8k out

$243/mo

$194/mo

Gemini 3.1 Flash Lite GPT-5.6 Luna · Derived from the standard-tier prices above, input and output tokens per request as stated, 30 days. Excludes caching discounts and batch. Try your own numbers.

On the atlas

Price band (A–H) × context band (1–6)

1 square apart. GPT-5.6 Luna (C6) sits 1 context band larger than Gemini 3.1 Flash Lite (C5).

Same square as Gemini 3.1 Flash Lite: Claude Haiku 5.5 ($0.10), Muse Spark 1.2 Contributor ($0.10), Muse Spark 1.3 Contributor ($0.10). Same square as GPT-5.6 Luna: GPT-6 Luna ($0.10), Llama 4 Scout ($0.10). Open C5 · Open C6

Gemini 3.1 Flash LiteGPT-5.6 LunaNearest neighboursOpen weights

View the map as a table (2 squares)

Square	Price band	Context band	Models
GRIDC5	$0.10–0.30	1M	Gemini 3.1 Flash Lite, Gemini 3.1 Flash Lite Preview, Qwen-Plus, DeepSeek V4 Flash Vision Exp, MiniMax-01, Qwen3.6 Flash, MiniMax M3.1 Flash
GRIDC6	$0.10–0.30	>1M	GPT-5.6 Luna, Llama 4 Scout, GPT-6 Luna

Capabilities side by side

Only what our records list

Gemini 3.1 Flash Lite

GPT-5.6 Luna

Vision input

Not disclosed

Audio input

Not disclosed

Open weights

Not marked open

Batch tier

Supported

Free tier

Not listed

Thinking tier

Not listed

Neither record lists input types, so we do not claim any.

Which should you choose?

Editorial

Choose Gemini 3.1 Flash Lite if…

Nothing in the recorded numbers favours Gemini 3.1 Flash Lite over GPT-5.6 Luna. Pick it for what our records do not cover — your own tests, or an account you already have with Google.

Choose GPT-5.6 Luna if…

you pay by the token: it costs $0.20 per 1M input against $0.25
output dominates your bill: $1.20 per 1M output against $1.50
your prompts are long: it takes 1,050,000 tokens against 1,048,576

Each reason is a fact from the tables above. Picking between them is our judgement, and we do not benchmark quality: price and context are what we can measure, so test both on your own prompts before you commit.

Questions

Is Gemini 3.1 Flash Lite better than GPT-5.6 Luna?

We do not benchmark quality, so we cannot say. On the recorded numbers: GPT-5.6 Luna is about 1.3× cheaper on input ($0.20 against $0.25 per 1M tokens) and on output. GPT-5.6 Luna has the larger context window (1.05M against 1.05M tokens). For a support chatbot at 10,000 chats a day, the standard-tier bill is about $248 a month for Gemini 3.1 Flash Lite and $198 for GPT-5.6 Luna. Which is better for you depends on your task; test both on your own prompts.

Which is cheaper, Gemini 3.1 Flash Lite or GPT-5.6 Luna?

GPT-5.6 Luna: $0.20 against $0.25 per 1M input tokens, and $1.20 against $1.50 per 1M output, on standard pricing.

How much does each cost per 1M tokens?

Gemini 3.1 Flash Lite: $0.25 input and $1.50 output. GPT-5.6 Luna: $0.20 input and $1.20 output. Standard tier, USD.

Which has the larger context window?

GPT-5.6 Luna, with 1,050,000 tokens. Gemini 3.1 Flash Lite has 1,048,576 tokens.

Do both offer batch pricing?

Gemini 3.1 Flash Lite lists a batch tier, at 50% of its standard price. GPT-5.6 Luna lists a batch tier, at 50% of its standard price.

Can both read images or audio?

Input types recorded for Gemini 3.1 Flash Lite: none recorded. For GPT-5.6 Luna: none recorded. Where a record lists none we say so rather than guess; check each vendor's documentation before relying on a capability.

Is either model open-weight?

Gemini 3.1 Flash Lite: not marked open-weight in our records. GPT-5.6 Luna: not marked open-weight in our records.

What would each cost for a support chatbot?

At 10,000 chats a day, 1,500 input and 300 output tokens each, 30 days, standard tier: about $248 a month for Gemini 3.1 Flash Lite and $198 for GPT-5.6 Luna. This is our calculation from the listed prices, not a quote.

About the two models

Gemini 3.1 Flash Lite

By Google. $0.25 input and $1.50 output per 1M tokens, 1.05M context, atlas square C5. Tiers listed: batch, standard.

Full specs & pricing →

GPT-5.6 Luna

By OpenAI. $0.20 input and $1.20 output per 1M tokens, 1.05M context, atlas square C6. Tiers listed: batch, standard.

Full specs & pricing →

Compare Gemini 3.1 Flash Lite with…

Compare GPT-5.6 Luna with…

Keep going in your AI

Opens with this page as the source. We add nothing else to the prompt.

Is Gemini 3.1 Flash Lite better than GPT-5.6 Luna?
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Which is cheaper, Gemini 3.1 Flash Lite or GPT-5.6 Luna?
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How much does each cost per 1M tokens?
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