Vellum LLM Leaderboard April update: Opus 4.7, Gemini 3.1 Pro, GPT-5.4 tied at the top

Vellum's April 2026 leaderboard shows three models tied at the top of the Artificial Analysis Intelligence Index at 57: Claude Opus 4.7, Gemini 3.1 Pro Preview, and GPT-5.4. Anthropic holds four of the top five spots; Opus 4.7 leads coding at 82% SWE-bench Verified and 1504 Elo on LM Arena.