Compare / DeepSeek V3.1 Terminus vs o3

DeepSeek V3.1 Terminus vs o3

Which is cheaper, which is more capable, and which does better at each kind of work, from 15 results on 3 sources that measured both models.

DeepSeek V3.1 Terminus
DeepSeek · profile
o3
OpenAI · profile
Results compared
15
Shared sources
3

DeepSeek V3.1 Terminus or o3? The short answer

  • DeepSeek V3.1 Terminus is cheaper: $0.45 against $3.50 per million tokens, 7.7 times less.
  • o3 scores higher on the Artificial Analysis Intelligence Index: 20.2 against 14.8.
  • On our business benchmarks, o3 ranks higher for agents and tool use, reasoning and knowledge and writing.

At a glance

DeepSeek V3.1 Terminuso3
Price per million tokens$0.27 in · $1.00 out$2.00 in · $8.00 out
Blended (3 in : 1 out)$0.45$3.50
Cheapest host, blended$0.45 (SiliconFlow, FP8)–
Intelligence Index14.820.2
Spring Prompt overall––
Output speed, tokens a second–126
Context window163,840 tokens200,000 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 V3.1 Terminuso3
Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls 84 of 161 13 of 161
Reasoning and knowledgeHard questions across science, maths and general knowledge 105 of 195 95 of 195
WritingWhat people prefer in blind comparisons, and judged writing quality 79 of 187 49 of 187
Sticking to the factsSummarising without inventing things, and factual answers not measured 91 of 153

Every shared result

BenchmarkMetricDeepSeek V3.1 Terminuso3
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4231,426
Arena (formerly LMArena)reportedCreative writingArena rating 1,4051,383
Arena (formerly LMArena)reportedInstruction followingArena rating 1,4201,403
Arena (formerly LMArena)reportedOverallArena rating 1,4171,432
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,4111,396
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 14.820.2
Artificial AnalysisreportedGPQA Diamond% of questions 79.2%82.7%
Artificial AnalysisreportedHumanity's Last Exam% of questions 16.4%20.1%
Artificial AnalysisreportedIFBench% of instructions 57.0%71.4%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 69.3%74.7%
Artificial AnalysisreportedTerminal-Bench Hard% of tasks 31.8%37.1%
Artificial AnalysisreportedΤ²-bench telecom% of tasks 37.1%80.7%
UGI LeaderboardreportedRequested-length error% off the requested word count 32.0%18.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.370.30
UGI LeaderboardreportedWriting scorescore out of 100 54.066.8

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 V3.1 Terminus better than o3?

It depends on the task. Among models available today, on our benchmarks and licensed sources, o3 ranks higher for agents and tool use, reasoning and knowledge and writing.

Which is cheaper, DeepSeek V3.1 Terminus or o3?

DeepSeek V3.1 Terminus costs $0.45 per million tokens (three input to one output), against $3.50 for o3.

Run DeepSeek V3.1 Terminus and o3 on your own prompt

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