Grok 4.20 Beta
Grok 4.20 Beta is an AI model released by SpaceXAI on Tuesday, Feb 17 2026, 90 days after Grok 4.1 Fast. Benchmark results (shown below) cover BullshitBench v2, ARC-AGI-2, and Arena Elo (Text).
Benchmarks
Nonsense detection
BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
56%
#13 of 64Best: Claude Opus 4.8 · 95%
Abstract reasoning
ARC-AGI-2Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better.
53.3%
#7 of 11Best: GPT-5.5 · 84.6%
Community preference
Arena Elo (Text)Real people chat with two anonymous AIs side by side and vote for the answer they prefer. Votes become a chess-style Elo rating on arena.ai — it measures which AI people actually like, not test scores. Higher is better.
1475
#17 of 17Best: Claude Fable 5 · 1509
Grok 4.20 Beta — frequently asked questions
- When was Grok 4.20 Beta released?
- Grok 4.20 Beta was released by SpaceXAI on Tuesday, Feb 17 2026.
- Who made Grok 4.20 Beta?
- Grok 4.20 Beta was built by SpaceXAI. Elon Musk's AI company building the Grok series of models. Founded in 2023 as xAI, now part of SpaceX.
- What benchmark scores did Grok 4.20 Beta get?
- Grok 4.20 Beta reports 3 tracked benchmark scores — BullshitBench v2: 56%; ARC-AGI-2: 53.3%; Arena Elo (Text): 1475. Scores are the figures published at release by SpaceXAI.
- Is Grok 4.20 Beta open source?
- No. Grok 4.20 Beta is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
- What came before and after Grok 4.20 Beta?
- SpaceXAI's previous tracked release was Grok 4.1 Fast on Nov 19 2025, 90 days earlier. It was followed by Grok 4.3 Beta on Apr 17 2026.