Compare / DeepSeek V3 vs GPT-5.6 Luna

DeepSeek V3 vs GPT-5.6 Luna

Which is cheaper, which is more capable, and which does better at each kind of work, from 18 results on 3 sources that measured both models.

DeepSeek V3
DeepSeek · profile
GPT-5.6 Luna
OpenAI · profile
Results compared
18
Shared sources
3

DeepSeek V3 or GPT-5.6 Luna? The short answer

  • GPT-5.6 Luna is cheaper: $0.45 against $0.45 per million tokens, 0% less.
  • GPT-5.6 Luna scores higher on the Artificial Analysis Intelligence Index: 37.3 against 8.5.
  • On our business benchmarks, DeepSeek V3 ranks higher for sticking to the facts.
  • On our business benchmarks, GPT-5.6 Luna ranks higher for agents and tool use, reasoning and knowledge and writing.

At a glance

DeepSeek V3GPT-5.6 Luna
Price per million tokens$0.26 in · $1.03 out$0.20 in · $1.20 out
Blended (3 in : 1 out)$0.45$0.45
Cheapest host, blended$0.45 (StreamLake)$0.23 (OpenAI)
Intelligence Index8.537.3
Spring Prompt overall––
Output speed, tokens a second––
Context window163,840 tokens1,050,000 tokens
WeightsOpenClosed
Developer based inChinathe US

Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.

Which is better for what

Each model's rank among models available today, for each kind of work, from our own benchmarks and licensed sources. The better rank is in green.

Use caseDeepSeek V3GPT-5.6 Luna
Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls 136 of 161 47 of 161
Professional workReal tasks from banking, consulting and law, business documents and freelance projects not measured 20 of 51
Reasoning and knowledgeHard questions across science, maths and general knowledge 168 of 195 38 of 195
WritingWhat people prefer in blind comparisons, and judged writing quality 115 of 187 57 of 187
Sticking to the factsSummarising without inventing things, and factual answers 25 of 153 59 of 153

Every shared result

BenchmarkMetricDeepSeek V3GPT-5.6 Luna
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,3501,463
Arena (formerly LMArena)reportedCreative writingArena rating 1,3491,412
Arena (formerly LMArena)reportedExpert promptsArena rating 1,3481,491
Arena (formerly LMArena)reportedInstruction followingArena rating 1,3431,446
Arena (formerly LMArena)reportedOverallArena rating 1,3581,454
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,3561,435
Artificial AnalysisreportedArtificial Analysis Coding Indexindex score 23.071.4
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 8.5037.3
Artificial AnalysisreportedGPQA Diamond% of questions 55.7%91.1%
Artificial AnalysisreportedHumanity's Last Exam% of questions 2.9%39.5%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 29.3%83.7%
Artificial AnalysisreportedSciCode% of problems 35.8%53.6%
Artificial AnalysisreportedTerminal-Bench 2.1% of tasks 16.9%80.9%
Artificial AnalysisreportedTerminal-Bench 4.0% of tasks 0.0%11.6%
Artificial AnalysisreportedΤ-bench banking% of tasks 4.7%31.1%
UGI LeaderboardreportedRequested-length error% off the requested word count 17.0%15.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.370.38
UGI LeaderboardreportedWriting scorescore out of 100 43.253.7

Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.

Quick answers

Is DeepSeek V3 better than GPT-5.6 Luna?

It depends on the task. Among models available today, on our benchmarks and licensed sources, DeepSeek V3 ranks higher for sticking to the facts; GPT-5.6 Luna ranks higher for agents and tool use, reasoning and knowledge and writing.

Which is cheaper, DeepSeek V3 or GPT-5.6 Luna?

GPT-5.6 Luna costs $0.45 per million tokens (three input to one output), against $0.45 for DeepSeek V3.

Run DeepSeek V3 and GPT-5.6 Luna on your own prompt

Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.