GPT-5.6 TerravsGrok 4.20 Beta

GPT-5.6 Terra
Grok 4.20 Beta
Benchmarks
Nonsense detection
BullshitBench v2
53%
56%Best
Prompt injection robustness
Gray Swan IPI · k = 1
5.4%
Prompt injection robustness
Gray Swan IPI · k = 10
26%
Prompt injection robustness
Gray Swan IPI · k = 15
30.4%
Agentic coding
CursorBench v3.2
64.9%
Agentic computer work
Frontier-Bench v0.1
20.8%
Agentic terminal coding
Terminal-Bench 2.1
84.3%
Abstract reasoning
ARC-AGI-2
53.3%
Community preference
Arena Elo (Text)
1467
1475Best
Community preference (code)
Arena Elo (Code)
1526
Overview
CompanyOpenAISpaceXAI
Release dateJun 26 2026Feb 17 2026
AccessProprietaryProprietary

Which is better: GPT-5.6 Terra or Grok 4.20 Beta?

Grok 4.20 Beta leads GPT-5.6 Terra on 2 of the 2 benchmarks they both report (BullshitBench v2, Arena Elo (Text)). Grok 4.20 Beta shipped 129 days before GPT-5.6 Terra, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On BullshitBench v2, Grok 4.20 Beta leads at 56% vs GPT-5.6 Terra at 53%. On Arena Elo (Text), Grok 4.20 Beta leads at 1475 vs GPT-5.6 Terra at 1467.

Frequently asked questions

GPT-5.6 Terra was released by OpenAI on Jun 26 2026.

Grok 4.20 Beta was released by SpaceXAI on Feb 17 2026.

Other comparisons