Claude Opus 5.5 vs Claude Opus 4.7

  • Claude Opus 5.5 rates higher on LMArena’s text leaderboard: 1516 against 1490.
  • Claude Opus 5.5 is cheaper: $4 / $20 per million input / output tokens, against $5 / $25 for Claude Opus 4.7.
  • On the 4 Vals AI benchmarks both have taken, Claude Opus 5.5 wins 3 and Claude Opus 4.7 wins 1 (Claude Opus 5.5: Vibe Code Bench, Tax Agent Bench, Legal Research Bench).
LMArena text rating over time
14601470148014901500Apr 26Jun 26Jul 26Sep 26Oct 26
LatestClaude Opus 4.7 1490

Side by side

Models (2/6)
  • Claude Opus 5.5
  • Claude Opus 4.7
BenchmarkClaude Opus 5.5Claude Opus 4.7
The model
LabAnthropicAnthropic
Released2026-09-222026-04-16
WeightsProprietaryProprietary
Context window1M1M
Input, per 1M tokens$4$5
Output, per 1M tokens$20$25
LMArena, people’s votes
LMArena TextMillions of people compare two anonymous models side by side and vote for the better answer1516#2 of 3511490#13 of 351
LMArena WebDevPeople ask two anonymous models to build the same web app, try both and vote for the better one1807#1 of 1241558#41 of 124
LMArena VisionSide-by-side votes on prompts that include an image1321#2 of 1461317#5 of 146
LMArena CodingLMArena’s text votes on prompts that ask for code1545#1 of 3461518#9 of 346
LMArena MathLMArena’s text votes on math prompts1518#6 of 3391498#17 of 339
LMArena Creative writingLMArena’s text votes on stories, poems and other creative writing1534#1 of 3491486#11 of 349
LMArena Hard promptsLMArena’s text votes on the hardest prompts1536#2 of 3511506#11 of 351
LMArena Instruction followingLMArena’s text votes on prompts with specific instructions to follow1539#1 of 3511498#9 of 351
Vals AI, overall
Vals IndexVals AI’s headline score70.18%#2 of 27—
Vals AI, coding
Terminal-Bench 4.0Frontier-difficulty tasks an agent completes in a real terminal65.15%#1 of 55—
SWE-benchReal GitHub issues from open-source projects—82.00%#21 of 85
Vibe Code BenchBuilding complete web apps from a plain-language brief, graded on whether the app works90.29%#5 of 11571.00%#41 of 115
Code MigrationRewriting working programs in a new language, graded on whether the new program still passes its tests81.01%#2 of 28—
LiveCodeBenchFresh competitive programming problems, collected after models’ training cut-offs to avoid contamination—85.07%#36 of 143
Vals AI, finance
Finance AgentThe core tasks of a financial analyst, done as an agent with research tools67.85%#1 of 31—
Finance IndexVals AI’s composite of finance tasks65.59%#1 of 31—
Tax Agent BenchAgentic research into US corporate tax questions45.57%#3 of 7623.74%#43 of 76
Vals AI, law
Legal IndexVals AI’s composite of legal tasks72.33%#7 of 28—
Legal Research BenchAgentic US legal research50.48%#7 of 8538.46%#35 of 85
Vals AI, medicine
MedCodeAssigning the right medical billing codes from clinical notes49.80%#19 of 10754.86%#7 of 107
Vals AI, reasoning
GPQA DiamondGraduate-level questions in biology, physics and chemistry that experts answer well and search does not—90.15%#26 of 138
MMLU-ProHarder, reasoning-focused multiple choice across 14 subjects, from law to engineering—89.87%#8 of 138
AIMEProblems from the American Invitational Mathematics Examination, a qualifier for the US Math Olympiad—96.25%#7 of 96
MMMUCollege-level questions that need both an image and text—85.55%#24 of 93
Terminal-Bench ScienceExpert-written scientific research workflows, run by an agent in a terminal47.14%#3 of 42—

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Questions

Which is better, Claude Opus 5.5 or Claude Opus 4.7?

Claude Opus 5.5 rates higher on LMArena’s text leaderboard: 1516 against 1490. Claude Opus 5.5 is cheaper: $4 / $20 per million input / output tokens, against $5 / $25 for Claude Opus 4.7. On the 4 Vals AI benchmarks both have taken, Claude Opus 5.5 wins 3 and Claude Opus 4.7 wins 1 (Claude Opus 5.5: Vibe Code Bench, Tax Agent Bench, Legal Research Bench).

Which is cheaper, Claude Opus 5.5 or Claude Opus 4.7?

Claude Opus 5.5 is cheaper: $4 / $20 per million input / output tokens, against $5 / $25 for Claude Opus 4.7.

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”.