whichllmmodel
Back to Dashboard

OpenAI GPT-5.6 Terra VS xAI Grok 4.5

✍️ Analysis by:the whichllmmodel Editorial Team|📅 Updated: June 2026

⚖️Our Take

Both models perform almost identically, with an average score gap of just 0.7%. We recommend choosing Grok 4.5 as it is the more cost-effective option (being 1.9x cheaper) without sacrificing any real-world capability.
Was this recommendation helpful?
Model Specs

GPT-5.6 Terra

Benchmarks & Scores

Coding (swe-bench-pro)
63.4%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)
92.9%

graduate-level science QA

Cost & Performance

Cost (per 1M tokens)
$5.63Input: $2.50 | Output: $15.00
Context WindowLarger
1.05M tokens
Model Specs

Grok 4.5

Benchmarks & Scores

Coding (swe-bench-pro)Winner (+1.3%)
64.7%

excellent at multi-file repositories, autonomous agents, and industrial codebases

Reasoning (gpqa-diamond)Winner (+0.1%)
93%

graduate-level science QA

Cost & Performance

Cost (per 1M tokens)1.9x cheaper
$3.00Input: $2.00 | Output: $6.00
Context Window
500k tokens

Frequently Asked Questions about GPT-5.6 Terra vs Grok 4.5 comparison

Grok 4.5 is cheaper than GPT-5.6 Terra. Grok 4.5 has a blended cost of $3.00/1M tokens, which is about 1.9x cheaper than GPT-5.6 Terra at $5.63/1M tokens.

Grok 4.5 is better for coding tasks on this benchmark. It scores 64.7% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) compared to GPT-5.6 Terra which scores 63.4%.