OpenAI vs Gemini API pricing: GPT vs Gemini per 1M tokens

OpenAI vs Gemini API pricing

Updated 2026-10-18. Prices from official pricing pages, quality ranks from LMArena.

Quick answer

Google is cheaper at the top end right now: Gemini 4 Argon lists at $2 input and $10 output per 1M tokens, vs $10 / $50 for GPT-6 Astra (from Dec 1, Argon goes up to $4 / $20). OpenAI is cheaper at the small end: GPT-6 Luna is $0.10 / $0.50 vs Gemini 3.5 Flash-Lite at $0.30 / $2.50. On LMArena, Google's best model ranks higher for chat, creative writing and reasoning; OpenAI's ranks higher for coding, agents, vision and long documents.

Model	Input	Output	Cached	30M in + 6M out	Chat rank	Coding rank
GPT-6 Astra	$10	$50	$1	$600	#13	#2
GPT-5.5	$5	$30	$0.50	$330	#12	#18
GPT-5.6 Sol	$4	$20	$0.40	$240	#9	n/a
GPT-5.6 Terra	$2	$12	$0.20	$132	#16	n/a
GPT-6.1 Sol	$2	$10	$0.10	$120	#10	#4
GPT-6 Sol	$2	$10	$0.20	$120	#18	#7
GPT-6 Luna	$0.10	$0.50	$0.01	$6	#22	#16
Gemini 3.1 Pro Preview	$2	$12	$0.20	$132	#8	#20
Gemini 4 Argon	$2	$10	$0.10	$120	#1	#8
Gemini 3.8 Flash	$0.75	$3.75	$0.075	$45	#5	#14
Gemini 3.5 Flash-Lite	$0.30	$2.50	$0.03	$24	#20	#21

USD per 1M tokens, paid tier, short-context rate, checked 2026-10-18. Ranks are positions among the models we track on LMArena (CC BY 4.0) Text Arena and Code Arena.

Tier by tier

Flagship: GPT-6 Astra $10 / $50 vs Gemini 4 Argon $2 / $10. Sample month (30M input, 6M output): $600 vs $120, so Astra costs 5.0x more. At today's price Argon also costs the same as GPT-6.1 Sol.
Workhorse: GPT-6.1 Sol $2 / $10 vs Gemini 3.8 Flash $0.75 / $3.75. Sample month: $120 vs $45. Sol is #4 for coding among tracked models, Flash #14.
Small and cheap: GPT-6 Luna $0.10 / $0.50 vs Gemini 3.5 Flash-Lite $0.30 / $2.50. Sample month: $6 vs $24.

Who ranks higher, task by task

Best model from each provider on the LMArena leaderboards we track (lower is better):

Chat: Gemini 4 Argon #1 vs GPT-5.6 Sol #9
Creative writing: Gemini 4 Argon #2 vs GPT-5.6 Sol #9
Reasoning: Gemini 4 Argon #1 vs GPT-5.5 #8
Coding: GPT-6 Astra #2 vs Gemini 4 Argon #8
Agents: GPT-6 Astra #2 vs Gemini 4 Argon #5
Vision: GPT-6.1 Sol #2 vs Gemini 3.8 Flash #5
Long documents: GPT-5.6 Sol #3 vs Gemini 3.1 Pro Preview #8

Launch prices that will change

Gemini 4 Argon: $2 in, $10 out now; $4 in, $20 out from Dec 1, per the official pricing page.
Gemini 3.8 Flash: $0.75 in, $3.75 out now; $1.50 in, $7.50 out from Jan 1, 2027, per the official pricing page.

Things the headline price hides

Free tier: Google's Gemini API has a free tier with usage limits for some models (Gemini 3.8 Flash is free of charge there); Gemini 4 Argon is paid only.
Long prompts: OpenAI charges a higher rate above 272K prompt tokens on GPT-6 models, and Gemini 3.1 Pro Preview charges more above 200K.
Thinking tokens: Google's output price includes thinking tokens, so reasoning-heavy calls cost more than the reply length suggests.

Other providers are often cheaper still: see the cheapest LLM API ranking, OpenAI vs Anthropic API pricing, or the full AI API price table. Paying for a chat app instead? Google AI Pro vs ChatGPT Plus compares the $20 plans.

Sources

FAQ

Is the Gemini API cheaper than OpenAI?

At the top end, yes for now: Gemini 4 Argon is $2 input and $10 output per 1M tokens vs $10 and $50 for GPT-6 Astra. At the small end OpenAI is cheaper: GPT-6 Luna costs $0.10 / $0.50 vs $0.30 / $2.50 for Gemini 3.5 Flash-Lite.

How much does the Gemini 4 Argon API cost?

$2 input and $10 output per 1M tokens through the launch period; from Dec 1 it is $4 input and $20 output. It is not on the free tier.

Which is better for coding, GPT or Gemini?

On LMArena's Code Arena, GPT-6 Astra is #2 and GPT-6.1 Sol #4 among the models we track, vs Gemini 4 Argon at #8. Ranks shift, so test on your own tasks.

Which is better for chat and writing?

Gemini 4 Argon is #1 on Text Arena and #2 for creative writing among tracked models; OpenAI's best are #9 and #9.

What is the cheapest OpenAI and Google model?

GPT-6 Luna ($0.10 / $0.50) and Gemini 3.5 Flash-Lite ($0.30 / $2.50) per 1M tokens, as of 2026-10-18.

Does the Gemini API have a free tier?

Yes, for some models, with usage limits, per Google's pricing page. Gemini 3.8 Flash is free of charge on the free tier; Gemini 4 Argon is paid only.