DeepSeek V3.2 vs GPT-5.6 Luna
DeepSeek against OpenAI, costed on the same three workloads. Neither is cheaper everywhere — which one wins depends on how much you read versus write.
DeepSeek V3.2 has been retired by its vendor. Its column shows the last rates it was sold at, kept for reference.
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Monthly bill, side by side
| Workload | DeepSeek V3.2 | GPT-5.6 Luna | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$723 | $887 | $164 (+23%) |
| Document summarizer 1,000 single-shot summaries a day |
$112 | $102 | $10.08 (+10%) |
| Coding agent 200 twelve-turn sessions a day |
$606 | $598 | $8.64 (+1%) |
No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.
The rate cards
| DeepSeek V3.2 | GPT-5.6 Luna | |
|---|---|---|
| Input, per 1M tokens | $0.28 | $0.2 |
| Output, per 1M tokens | $0.4 | $1.2 |
| Cached input | $0.028 | $0.02 |
| Context window | 164K | 922K |
| Maximum output | 164K | 128K |
| Reasoning model | yes | yes |
| Vision | no | yes |
Beyond the price
- GPT-5.6 Luna reads up to 922K tokens of context in one request; DeepSeek V3.2 stops at 164K.
- DeepSeek V3.2 can write up to 164K tokens in one response, against 128K for GPT-5.6 Luna.
- Only GPT-5.6 Luna accepts images as input.
- Only GPT-5.6 Luna offers a batch discount — 50% off both rates for work that can wait.
Run this comparison on your own numbers
Full detail: DeepSeek V3.2 pricing · GPT-5.6 Luna pricing
More comparisons
Other head-to-heads that include DeepSeek V3.2 or GPT-5.6 Luna.
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- GPT-5.6 Luna vs Claude Haiku 5.5
- GPT-5.6 Luna vs Qwen3 Next 80B
- GPT-5.6 Luna vs DeepSeek V4 Flash
Common questions
Which is cheaper, DeepSeek V3.2 or GPT-5.6 Luna?
Neither is cheaper everywhere — which one wins depends on how much you read versus write.
How much would DeepSeek V3.2 and GPT-5.6 Luna cost each month?
On PromptSpend's standard workloads, per month: support chatbot: DeepSeek V3.2 $723, GPT-5.6 Luna $887 (DeepSeek V3.2 is cheaper by $164); document summarizer: DeepSeek V3.2 $112, GPT-5.6 Luna $102 (GPT-5.6 Luna is cheaper by $10.08); coding agent: DeepSeek V3.2 $606, GPT-5.6 Luna $598 (GPT-5.6 Luna is cheaper by $8.64). No prompt caching and no batch discount is assumed.
How do DeepSeek V3.2 and GPT-5.6 Luna differ apart from price?
GPT-5.6 Luna reads up to 922K tokens of context in one request; DeepSeek V3.2 stops at 164K. DeepSeek V3.2 can write up to 164K tokens in one response, against 128K for GPT-5.6 Luna. Only GPT-5.6 Luna accepts images as input. Only GPT-5.6 Luna offers a batch discount — 50% off both rates for work that can wait.