Claude Opus 5 vs Gemini 3.1 Pro Preview

  • Claude Opus 5 rates higher on LMArena’s text leaderboard: 1508 against 1480.
  • Gemini 3.1 Pro Preview is cheaper: $2 / $12 per million input / output tokens, against $5 / $25 for Claude Opus 5.
  • On the 11 Vals AI benchmarks both have taken, Claude Opus 5 wins 10 and Gemini 3.1 Pro Preview wins 1 (Claude Opus 5: Terminal-Bench 4.0, SWE-bench, Vibe Code Bench).
LMArena text rating over time
14701480149015001510Feb 26Apr 26Jun 26Aug 26Oct 26
LatestGemini 3.1 Pro Preview 1480

Side by side

Models (2/6)
  • Claude Opus 5
  • Gemini 3.1 Pro Preview
BenchmarkClaude Opus 5Gemini 3.1 Pro Preview
The model
LabAnthropicGoogle
Released2026-07-242026-02-19
WeightsProprietaryProprietary
Context window1M1M
Input, per 1M tokens$5$2
Output, per 1M tokens$25$12
LMArena, people’s votes
LMArena TextMillions of people compare two anonymous models side by side and vote for the better answer1508#4 of 3511480#19 of 351
LMArena WebDevPeople ask two anonymous models to build the same web app, try both and vote for the better one1691#9 of 1241447#78 of 124
LMArena VisionSide-by-side votes on prompts that include an image1320#3 of 1461296#22 of 146
LMArena CodingLMArena’s text votes on prompts that ask for code1533#4 of 3461484#48 of 346
LMArena MathLMArena’s text votes on math prompts1533#2 of 3391486#28 of 339
LMArena Creative writingLMArena’s text votes on stories, poems and other creative writing1495#5 of 3491482#14 of 349
LMArena Hard promptsLMArena’s text votes on the hardest prompts1527#4 of 3511485#30 of 351
LMArena Instruction followingLMArena’s text votes on prompts with specific instructions to follow1518#5 of 3511466#35 of 351
Vals AI, coding
Terminal-Bench 4.0Frontier-difficulty tasks an agent completes in a real terminal53.53%#9 of 552.52%#49 of 55
SWE-benchReal GitHub issues from open-source projects97.00%#1 of 8578.80%#28 of 85
Vibe Code BenchBuilding complete web apps from a plain-language brief, graded on whether the app works88.40%#9 of 11532.03%#72 of 115
LiveCodeBenchFresh competitive programming problems, collected after models’ training cut-offs to avoid contamination89.03%#4 of 14388.48%#6 of 143
Vals AI, finance
Tax Agent BenchAgentic research into US corporate tax questions45.55%#4 of 769.29%#62 of 76
Vals AI, law
Legal Research BenchAgentic US legal research55.29%#2 of 8520.67%#62 of 85
Vals AI, medicine
MedCodeAssigning the right medical billing codes from clinical notes63.57%#1 of 10759.06%#2 of 107
MedQAMedical licensing exam questions, measured on accuracy and on robustness to bias—96.37%#3 of 92
Vals AI, reasoning
GPQA DiamondGraduate-level questions in biology, physics and chemistry that experts answer well and search does not93.43%#8 of 13895.45%#1 of 138
MMLU-ProHarder, reasoning-focused multiple choice across 14 subjects, from law to engineering91.59%#2 of 13890.99%#4 of 138
AIMEProblems from the American Invitational Mathematics Examination, a qualifier for the US Math Olympiad—98.13%#1 of 96
MMMUCollege-level questions that need both an image and text89.88%#2 of 9388.21%#10 of 93
Terminal-Bench ScienceExpert-written scientific research workflows, run by an agent in a terminal27.14%#9 of 421.43%#35 of 42

Add models in the compare tool.

Questions

Which is better, Claude Opus 5 or Gemini 3.1 Pro Preview?

Claude Opus 5 rates higher on LMArena’s text leaderboard: 1508 against 1480. Gemini 3.1 Pro Preview is cheaper: $2 / $12 per million input / output tokens, against $5 / $25 for Claude Opus 5. On the 11 Vals AI benchmarks both have taken, Claude Opus 5 wins 10 and Gemini 3.1 Pro Preview wins 1 (Claude Opus 5: Terminal-Bench 4.0, SWE-bench, Vibe Code Bench).

Which is cheaper, Claude Opus 5 or Gemini 3.1 Pro Preview?

Gemini 3.1 Pro Preview is cheaper: $2 / $12 per million input / output tokens, against $5 / $25 for Claude Opus 5.

Sources

Every number on this page comes from these sources; models without a published number show none. Download the data. Cite as “Nexus Explorer, nexus.inc/models”.