Standard Compute
Cost per coding-agent request

Is DeepSeek V4 Flash or GPT-5.6 Luna cheaper for coding agents?

For coding agents, GPT-5.6 Luna costs 1.3x as much as DeepSeek V4 Flash per request ($0.0084 vs $0.0067 on our measured traffic), because GPT-5.6 Luna lists at $0.20 input, $0.02 cached input and $1.20 output per million tokens against $0.30, $0.006 and $1.20 for DeepSeek V4 Flash, and GPT-5.6 Luna charges more for prompts over 272K tokens.

List prices: DeepSeek API pricing, OpenAI API pricing, checked 2026-10-13. Request costs: Standard Compute gateway data, 79,301 coding-agent requests from 75 users, Sep 13 to Oct 12, 2026. How we compute this

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Cost per coding-agent request, side by side

Cost at list priceDeepSeek V4 FlashGPT-5.6 Luna
Prompt under 100K tokens50% of requests, 87% of input cached$0.0033$0.0032
Prompt of 100K to 272K39% of requests, 88% of input cached$0.0080$0.0080
Prompt over 272K tokens11% of requests, 86% of input cached$0.018$0.034
Average request$0.0067$0.0084
100 requests$0.67$0.84
Median session16 requests; a session ends after 10 idle minutes$0.091$0.092
A month of regular usemedian of 20 users active on 5+ days$9.13$11.83

Each logged request priced at the vendor’s list rates for its own token counts, including cache reads and any higher rate for long prompts. Average output: 698 tokens per request.

Benchmarks, speed and latency, side by side

Artificial AnalysisDeepSeek V4 FlashGPT-5.6 Luna
Intelligence Index10 evaluations, 0 to 1003937
Terminal-Bench 4.0agentic coding in a terminal26.8%11.6%
Output speedmedian195 tokens/s123 tokens/s
Time to first answer tokenincludes thinking time11 s117 s

Source: Artificial Analysis (artificialanalysis.ai). Measured variants: DeepSeek V4.1 Flash (Max), speed on DeepSeek; GPT-5.6 Luna (Max), speed on OpenAI. Fetched October 13, 2026. Artificial Analysis runs Terminal-Bench 4.0 in its own setup, so its scores differ from the tbench.ai leaderboard.

What to watch for

The gap widens on long prompts: under 100K tokens GPT-5.6 Luna costs 1.0x as much per request, over 272K 1.9x. 87% of agent input is read from cache, and GPT-5.6 Luna charges $0.02 per million for it against $0.006. DeepSeek V4 Flash is superseded: DeepSeek V4.1 Flash costs $0.0067 per request.

FAQ

Is DeepSeek V4 Flash cheaper than GPT-5.6 Luna for coding agents?
Yes, at list prices. 100 average coding-agent requests cost $0.67 on DeepSeek V4 Flash and $0.84 on GPT-5.6 Luna. A median 16-request session costs $0.091 vs $0.092. Measured on 79,301 real coding-agent requests (Sep 13 to Oct 12, 2026).
How much does a month of GPT-5.6 Luna vs DeepSeek V4 Flash cost?
For the median regular user in our data (1,478 requests in 30 days), about $11.83 on GPT-5.6 Luna and $9.13 on DeepSeek V4 Flash at list price. Heavier users pay proportionally more.
DeepSeek V4 Flash vs GPT-5.6 Luna: which is better for agents?
DeepSeek V4 Flash scores higher on output quality (7.7/10 vs 7.4/10), while DeepSeek V4 Flash is the cheaper option. DeepSeek V4 Flash is best for existing setups that still call the deepseek-v4-flash name; GPT-5.6 Luna is best for cheap subtasks in existing GPT-5.6 setups. Live community votes on this page show what people actually prefer.
Can I switch between DeepSeek V4 Flash and GPT-5.6 Luna in the same agent?
Yes. Model-agnostic agents (Cline, Aider, OpenClaw, Hermes Agent, Kilo Code, OpenCode) let you swap models per task. Many people route hard tasks to the stronger model and routine work to the cheaper one.

Community vote

Pick a winner in each dimension. You can change your vote any time. 8 votes cast so far.

Output Quality

Correctness and depth of what it produces

0%2 votes100%

Agentic Ability

Tool calls, instruction-following, and multi-step tasks

0%1 vote100%

Speed

Tokens per second and time-to-first-token

100%2 votes0%

Value for Money

How much capability you get per dollar

50%2 votes50%

Reliability

Consistent results: fewer refusals, loops and format breaks

0%1 vote100%

What voters say

Anonymous rationales from people who voted on DeepSeek V4 Flash vs GPT-5.6 Luna.

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