Gemini 3.8 Flash High vs GPT-6 Luna Max: which is cheaper?

Gemini 3.8 Flash High leads the intelligence index 30.8 to 27.9. Price per token, response speed and when to pick each.

Metric	Gemini 3.8 Flash (High)	GPT-6 Luna (Max)
Intelligence Index	30.8	27.9
Input price (per 1M tokens)	$0.75	$0.10
Output price (per 1M tokens)	$3.75	$0.50
Output speed (tokens/s)	121	121
Time to first token	27s	2.0 min
Release date	2026-09-02	2026-09-22

Metric

Gemini 3.8 Flash (High)

GPT-6 Luna (Max)

Intelligence Index

30.8

27.9

Input price (per 1M tokens)

$0.75

$0.10

Output price (per 1M tokens)

$3.75

$0.50

Output speed (tokens/s)

121

Time to first token

27s

2.0 min

Release date

2026-09-02

2026-09-22

There is very little daylight between Gemini 3.8 Flash (High) (Google) and GPT-6 Luna (Max) (OpenAI) on the overall index. This page is written automatically from catalogue numbers only: benchmark scores, list prices and measured speed. Cost is where they split the most, with GPT-6 Luna Max working out at about 13% of Gemini 3.8 Flash High's blended rate.

What they cost

The list prices are $0.75 in and $3.75 out for Gemini 3.8 Flash High, and $0.10 in and $0.50 out for GPT-6 Luna Max, per million tokens. That makes GPT-6 Luna Max's output 87% cheaper.

Take 1 million input tokens and 200,000 output tokens: that comes to $1.50 on Gemini 3.8 Flash High and $0.20 on GPT-6 Luna Max. A bigger example, a month of coding-assistant traffic at 30 million input and 3 million output tokens, costs $33.75 on Gemini 3.8 Flash High and $4.50 on GPT-6 Luna Max: a gap of $29.25. On a 3:1 blend of input to output tokens, that works out to $1.50 versus $0.20 per million.

When they came out

GPT-6 Luna Max arrived on September 22, 2026, 20 days after Gemini 3.8 Flash High (September 2, 2026). That is close enough to count them as the same generation.

Throughput and time to first token

Measured output speed is 121 tokens per second for Gemini 3.8 Flash High and 121 tokens per second for GPT-6 Luna Max. There is little to choose between them on raw output speed. The wait for the first token averages 27 seconds on Gemini 3.8 Flash High against 2.0 minutes on GPT-6 Luna Max. GPT-6 Luna Max waits 4.5 times as long before its first token. A first-token wait of that length suits background work better than live conversation.

Put together, a 2,000-token answer would take about 44 seconds from Gemini 3.8 Flash High and 2.3 minutes from GPT-6 Luna Max, counting the first-token wait.

The headline benchmark

On the intelligence index, Gemini 3.8 Flash High scores 30.8 against 27.9 for GPT-6 Luna Max. The lead is visible but narrow, so it should not decide the choice on its own. Put another way, GPT-6 Luna Max would need 10% more on this index to draw level.

Among 109 active scored models, Gemini 3.8 Flash High sits 50th and GPT-6 Luna Max 62nd.

For coding or maths work specifically, the catalogue has no dedicated index on either side yet.

Cost per point of intelligence

Per point of intelligence index, Gemini 3.8 Flash High costs $0.049 of blended price per million tokens and GPT-6 Luna Max $0.0072. Gemini 3.8 Flash High costs 6.8 times as much per point, which is the price of its lead.

Common questions about Gemini 3.8 Flash High and GPT-6 Luna Max

Is Gemini 3.8 Flash High better than GPT-6 Luna Max?

Neither wins everywhere: Gemini 3.8 Flash High scores higher on the intelligence index, 30.8 to 27.9; GPT-6 Luna Max is 87% cheaper on blended price; and Gemini 3.8 Flash High reaches its first token sooner.

Which model has lower latency?

Their output speeds are close: 121 tokens per second for Gemini 3.8 Flash High and 121 tokens per second for GPT-6 Luna Max. Gemini 3.8 Flash High reaches its first token sooner (27 seconds against 2.0 minutes).

Is GPT-6 Luna Max cheaper than Gemini 3.8 Flash High?

GPT-6 Luna Max is cheaper on a blended basis. Gemini 3.8 Flash High lists $0.75 per million input tokens and $3.75 per million output tokens; GPT-6 Luna Max lists $0.10 and $0.50. For 1 million input and 200,000 output tokens that is $1.50 against $0.20.

Who makes Gemini 3.8 Flash High and GPT-6 Luna Max?

Gemini 3.8 Flash High is made by Google and GPT-6 Luna Max by OpenAI. Gemini 3.8 Flash High was released on September 2, 2026 and GPT-6 Luna Max on September 22, 2026.

Was this comparison tested by hand?

The figures are the recorded benchmark, price and speed data in Franklin AI's model catalogue. This page is written from that data automatically; neither model was tested by hand for it.

Final whistle

GPT-6 Luna Max has more going for it here, but Gemini 3.8 Flash High is not without an argument. Pick GPT-6 Luna Max if cost matters ($0.50 against $3.75 per million output tokens). Pick Gemini 3.8 Flash High if users are waiting on the first word and you need the higher overall score (30.8 against 27.9).

Where the numbers come from

The scores, speed and prices in this comparison come from independent third-party model evaluations that Franklin AI syncs each day, and the article was written from a snapshot of them. For the latest results, open the Gemini 3.8 Flash (High) and GPT-6 Luna (Max) pages. The AI Benchmark methodology explains how that data is collected and shown.