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GPT-6 Luna vs Gemini 2.5 Flash-Lite: API cost

Standard, cached and batch API prices for GPT-6 Luna (OpenAI) and Gemini 2.5 Flash-Lite (Google), and what each costs for your usage.

Prices last checked: how

Gemini 2.5 Flash-Lite is cheaper than GPT-6 Luna at standard rates, with the same input price and 20% cheaper output.

Your usage
GPT-6 Luna / month $7.80 $0.00026 per request
  • Input $3.00
  • Cached input $0.3
  • Output $4.50
Gemini 2.5 Flash-Lite / month $6.90 $0.00023 per request
  • Input $3.00
  • Cached input $0.3
  • Output $3.60
Gemini 2.5 Flash-Lite is cheaper for this usage by $0.9 a month (12% less).

How cost changes with reply length

  • GPT-6 Luna
  • Gemini 2.5 Flash-Lite
$0$0.2$0.4$0.602004006008001,000Output tokens per 1,000 input tokensGPT-6 LunaGemini 2.5 Flash-…
Cost of 1,000 requests with 1,000 input tokens each, at standard rates without caching. Hover or use the arrow keys to read values.
Show as a table
Output tokensGPT-6 LunaGemini 2.5 Flash-Lite
0$0.1$0.1
250$0.23$0.2
500$0.35$0.3
750$0.47$0.4
1,000$0.6$0.5

Price per million tokens

Token typeGPT-6 LunaGemini 2.5 Flash-Lite
Input$0.10$0.10
Cached input$0.01$0.01
Output$0.50$0.40
Batch input$0.05$0.05
Batch cached input$0.005$0.01
Batch output$0.25$0.20

GPT-6 Luna: Long prompts are billed at higher long-context rates.

Gemini 2.5 Flash-Lite: Audio input costs more.

Standard rates in USD, before tax OpenAI API pricing Gemini API pricing

Monthly cost for typical workloads

WorkloadGPT-6 LunaGemini 2.5 Flash-Lite
Support chatbot
2,000 in / 300 out tokens, 1,000 requests a day, 50% cached
$7.80$6.90
Document summaries
10,000 in / 800 out tokens, 200 requests a day
$8.40$7.92
Tagging / classifying
400 in / 20 out tokens, 20,000 requests a day
$30.00$28.80
Standard rates in USD, before tax. A month is 30 days.

Or see GPT-6 Luna pricing, Gemini 2.5 Flash-Lite pricing, or compare any two models.

FAQ

Frequently asked questions

Is GPT-6 Luna cheaper than Gemini 2.5 Flash-Lite?

Gemini 2.5 Flash-Lite is cheaper than GPT-6 Luna at standard rates, with the same input price and 20% cheaper output. Based on standard API rates last checked on 30 Sept 2026.

How much do GPT-6 Luna and Gemini 2.5 Flash-Lite cost per million tokens?

GPT-6 Luna: $0.10 per million input tokens and $0.50 per million output tokens. Gemini 2.5 Flash-Lite: $0.10 input and $0.40 output. These are standard rates in USD, before tax, from each provider’s own pricing page.

Which is cheaper with the Batch API?

GPT-6 Luna’s batch rates are $0.05 input and $0.25 output per million tokens (50% off); Gemini 2.5 Flash-Lite’s batch rates are $0.05 input and $0.20 output per million tokens (50% off).

Does prompt caching change the comparison?

GPT-6 Luna charges $0.01 per million cached input tokens, against $0.10 for normal input; Gemini 2.5 Flash-Lite charges $0.01 per million cached input tokens, against $0.10 for normal input. Cache write and storage charges are extra and aren’t included here.

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