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DeepSeek V4 Pro vs GPT-6 Luna: pricing and benchmarks

GPT-6 Luna is 92% cheaper on input tokens ($0.10 vs $1.32 per 1M). GPT-6 Luna is 87% cheaper on output tokens ($0.50 vs $3.96 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $646.80 for DeepSeek V4 Pro, 91% less. Epoch AI has not published a capability index score for GPT-6 Luna yet.

Prices verified September 26, 2026.

Which should you choose?

Overall capability
Too close to call

Epoch AI has not published a capability index score for GPT-6 Luna yet.

Price
GPT-6 Luna

GPT-6 Luna costs $0.20 per 1M tokens (3:1 input-to-output mix) vs $1.98 for DeepSeek V4 Pro, 90% less.

Pricing and specs

DeepSeek V4 ProGPT-6 Luna
ProviderDeepSeekOpenAI
API model IDdeepseek-v4-progpt-6-luna
Input / 1M tokens$1.32$0.10
Cached input / 1M tokens$0.044$0.01
Output / 1M tokens$3.96$0.50
Long-context rates—$0.20 in / $0.75 out on long-context requests
Context window1M tokens1.05M tokens
Max output384K tokens128K tokens
Batch discount—50% off

Benchmarks

DeepSeek V4 ProGPT-6 Luna
Epoch Capabilities Index155.5—
GPQA Diamond· Science reasoning88.9%—
FrontierMath (Tiers 1–3)· Advanced math64.6%—
SimpleQA Verified· Factual accuracy52.9%—
ARC-AGI-2· Abstract reasoning61.3%—
DeepSWE· Coding——
APEX-Agents· Agentic work——

Source: Epoch AI, best recorded result per model (CC BY 4.0). A dash means no published score. See all benchmarks

Monthly cost for real workloads

WorkloadDeepSeek V4 ProGPT-6 LunaDifference
Support chatbot
100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each.
$356.40$35.00GPT-6 Luna 90% cheaper
Document Q&A (RAG)
50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each.
$646.80$55.00GPT-6 Luna 91% cheaper
Coding agent
10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens.
$249.92$24.80GPT-6 Luna 90% cheaper

Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.

DeepSeek V4 Pro vs GPT-6 Luna cost calculator

Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.

DeepSeek V4 Pro pricing notes

DeepSeek’s larger V4 model with thinking and non-thinking modes and tool calls.

  • Prices shown are peak rates. Off-peak rates are half: peak hours are 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday.
  • Vision input is not supported.
DeepSeek official pricing ↗

GPT-6 Luna pricing notes

OpenAI’s most efficient GPT-6 model, for focused, high-volume tasks.

  • Cache writes are billed at $0.125 per 1M tokens.
  • Fast mode costs 2x the standard rate; Flex costs half.
  • Regional (data residency) endpoints add a 10% uplift, and EU data residency is available only with standard processing.
OpenAI official pricing ↗

Frequently asked questions

Is DeepSeek V4 Pro cheaper than GPT-6 Luna?
GPT-6 Luna is 92% cheaper on input tokens ($0.10 vs $1.32 per 1M). GPT-6 Luna is 87% cheaper on output tokens ($0.50 vs $3.96 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $646.80 for DeepSeek V4 Pro, 91% less.
Which is more capable, DeepSeek V4 Pro or GPT-6 Luna?
Epoch AI has not published a capability index score for GPT-6 Luna yet.
How much does DeepSeek V4 Pro cost per 1M tokens?
DeepSeek V4 Pro costs $1.32 per 1M input tokens and $3.96 per 1M output tokens, and $0.044 per 1M cached input tokens on DeepSeek’s standard tier.
How much does GPT-6 Luna cost per 1M tokens?
GPT-6 Luna costs $0.10 per 1M input tokens and $0.50 per 1M output tokens, and $0.01 per 1M cached input tokens on OpenAI’s standard tier.
Which has the larger context window, DeepSeek V4 Pro or GPT-6 Luna?
GPT-6 Luna has the larger context window: 1.05M tokens versus 1M for DeepSeek V4 Pro.

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