Muse Spark 1.3 vs Kimi K3

  • Muse Spark 1.3 rates higher on LMArena’s text leaderboard: 1491 against 1475.
  • Muse Spark 1.3 is cheaper: $1.25 / $4.25 per million input / output tokens, against $0.24 / $11 for Kimi K3.
  • On the 5 Vals AI benchmarks both have taken, Muse Spark 1.3 wins 2 and Kimi K3 wins 3 (Muse Spark 1.3: Tax Agent Bench, Terminal-Bench Science).
LMArena text rating over time
14601468147514831490Jul 16Aug 9Sep 3Sep 27Oct 22
LatestKimi K3 1475

Side by side

Models (2/6)
  • Muse Spark 1.3
  • Kimi K3
BenchmarkMuse Spark 1.3Kimi K3
The model
LabMetaMoonshot AI
Released2026-09-022026-07-16
WeightsProprietaryOpen
Context window1M1M
Input, per 1M tokens$1.25$0.24
Output, per 1M tokens$4.25$10.80
LMArena, people’s votes
LMArena TextMillions of people compare two anonymous models side by side and vote for the better answer1491#10 of 3511475#25 of 351
LMArena WebDevPeople ask two anonymous models to build the same web app, try both and vote for the better one1657#16 of 1241655#17 of 124
LMArena VisionSide-by-side votes on prompts that include an image1308#12 of 146—
LMArena CodingLMArena’s text votes on prompts that ask for code1511#13 of 3461508#16 of 346
LMArena MathLMArena’s text votes on math prompts1502#13 of 3391493#20 of 339
LMArena Creative writingLMArena’s text votes on stories, poems and other creative writing1462#23 of 3491456#28 of 349
LMArena Hard promptsLMArena’s text votes on the hardest prompts1504#13 of 3511495#17 of 351
LMArena Instruction followingLMArena’s text votes on prompts with specific instructions to follow1479#21 of 3511485#16 of 351
Vals AI, overall
Vals IndexVals AI’s headline score—52.95%#20 of 27
Vals AI, coding
Terminal-Bench 4.0Frontier-difficulty tasks an agent completes in a real terminal10.61%#41 of 5517.17%#34 of 55
SWE-benchReal GitHub issues from open-source projects—93.40%#8 of 85
Vibe Code BenchBuilding complete web apps from a plain-language brief, graded on whether the app works82.86%#21 of 11584.97%#16 of 115
Code MigrationRewriting working programs in a new language, graded on whether the new program still passes its tests—28.59%#23 of 28
LiveCodeBenchFresh competitive programming problems, collected after models’ training cut-offs to avoid contamination—87.19%#18 of 143
Vals AI, finance
Finance AgentThe core tasks of a financial analyst, done as an agent with research tools—60.01%#21 of 31
Finance IndexVals AI’s composite of finance tasks—57.95%#11 of 31
Tax Agent BenchAgentic research into US corporate tax questions35.97%#13 of 7633.37%#15 of 76
Vals AI, law
Legal IndexVals AI’s composite of legal tasks—71.72%#10 of 28
Legal Research BenchAgentic US legal research40.87%#29 of 8546.15%#16 of 85
Vals AI, medicine
MedCodeAssigning the right medical billing codes from clinical notes—49.36%#23 of 107
Vals AI, reasoning
GPQA DiamondGraduate-level questions in biology, physics and chemistry that experts answer well and search does not—92.93%#12 of 138
MMLU-ProHarder, reasoning-focused multiple choice across 14 subjects, from law to engineering—87.97%#22 of 138
MMMUCollege-level questions that need both an image and text—88.15%#11 of 93
Terminal-Bench ScienceExpert-written scientific research workflows, run by an agent in a terminal4.29%#25 of 421.43%#38 of 42

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Questions

Which is better, Muse Spark 1.3 or Kimi K3?

Muse Spark 1.3 rates higher on LMArena’s text leaderboard: 1491 against 1475. Muse Spark 1.3 is cheaper: $1.25 / $4.25 per million input / output tokens, against $0.24 / $11 for Kimi K3. On the 5 Vals AI benchmarks both have taken, Muse Spark 1.3 wins 2 and Kimi K3 wins 3 (Muse Spark 1.3: Tax Agent Bench, Terminal-Bench Science).

Which is cheaper, Muse Spark 1.3 or Kimi K3?

Muse Spark 1.3 is cheaper: $1.25 / $4.25 per million input / output tokens, against $0.24 / $11 for Kimi K3.

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”.