Which model leads Longform Writing eval (Kimi K2 Thinking system card)?

Q: Which model leads Longform Writing eval (Kimi K2 Thinking system card)?

Claude Sonnet 4.5 tops the board at 79.8

Longform Writing eval (Kimi K2 Thinking system card) Leaderboard — Model Scores

Pro Mode — raw scores, one benchmark under the lensofficial card harness

The field · 5 measured

62.879.8

5 models measured, most on the official card harness. Claude Sonnet 4.5 tops the board at 79.8.

5 measured·Lifecycle Updated Oct 8, 2026Score basis

#◆Vendor$/M in$/M out

Leader — ignites whiteField — fill cools with scoreIndependently verified only0 of 5Bars show 62.8–79.8 · ◆ solid = first-party or better · outlined = arm's-length

01Claude Sonnet 4.5+1 altAnthropic79.8$3.0/M$15.0/M$0.113

02Kimi K2 ThinkingMoonshot73.8$0.60/M$2.5/M$0.021

03DeepSeek-V3.2+1 altDeepSeek72.5$0.28/M$0.42/M$0.005

04GPT-5OpenAI71.43P$1.3/M$10.0/M$0.079

05Kimi K2 Instruct+1 altMoonshot62.8$0.57/M$2.3/M$0.023

◆ solid = independently verified · aggregator attested · vendor attributed — outlined = cross-reference · source-attributed. Dimmed ◆ = confidence inferred. “+N alts” = alternate disclosures in the drawer with why-demoted. Prices per million tokens; $/point = input price ÷ score. Every row opens its model dossier.

Verification: 5 models scored · 0 independently verified · 3 vendor cross-reference · 2 vendor-reported · 0 with source disagreement. How these tiers are assigned