Model comparison · scores as of 19 October 2026
Claude Opus 5.5 vs Grok 4.20 Beta 1
Claude Opus 5.5 is ahead: it scores 1508 on LMArena against Grok 4.20 Beta 1’s 1475, a 33-point lead.
| Claude Opus 5.5 | Grok 4.20 Beta 1 | |
|---|---|---|
| Made by | Anthropic | xAI |
| LMArena text score | 1508 | 1475 |
| Leaderboard position | #0 of 87 | #0 of 87 |
| Released | 22 September 2026 | 17 February 2026 |
| Lab’s AI Race rank today | #2 | #7 |
| Lab capability score | 93.0 | 80.0 |
LMArena scores come from millions of blind side-by-side votes: people see two anonymous answers and pick the better one. It measures how good answers feel to people across everyday tasks, not one narrow skill. More on benchmarks.
Which labs are winning overall?
| # | Lab | Index | 24h | Flagship |
|---|---|---|---|---|
| 1 | Meta | 94.3 | −0.1 | Muse Wonder |
| 2 | Anthropic | 91.6 | −0.1 | Claude Opus 5.5 |
| 3 | Google DeepMind | 89.7 | −0.1 | Gemini 4 Argon |
| 4 | Alibaba Qwen | 80.6 | −0.1 | Qwen3.8-Max |
| 5 | OpenAI | 80.4 | ±0.0 | GPT-6 Astra |
| 6 | DeepSeek | 73.8 | −0.1 | DeepSeek V4.1-Flash |
| 7 | xAI | 70.8 | −0.1 | Grok 4.7 |
| 8 | Moonshot AI | 58.8 | ±0.0 | Kimi K3 |
| 9 | Mistral AI | 56.5 | ±0.0 | Mistral Large 4 |
| 10 | Apple | 50.1 | ±0.0 | Siri AI (iOS 27) |
See the labs head to head: Anthropic vs xAI · full model leaderboard