tokevenGPTvsGrok
GPT 5.6 Terra vs Grok 4.20 Reasoning
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
GPT 5.6 Terra
Mid-tierGrok 4.20 Reasoning
Mid-tierInput $/MTok
$2.00
$1.25
Output $/MTok
$12.00
$2.50
Cache discount
90% off
84% off
Context
922K
1,000K
Quality
Task confidence comparison
Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
86
vs
0
Code Review
84
vs
0
Summarization
92
vs
0
Q&A
92
vs
0
Extraction
90
vs
0
Reasoning
82
vs
0
Classification
89
vs
0
Creative Writing
80
vs
0
GPT 5.6 Terra
Grok 4.20 Reasoning
Guidance
When to use GPT 5.6 Terra vs Grok 4.20 Reasoning
Choose GPT 5.6 Terra when...
- Similar performance; consider provider preference or ecosystem fit.
Choose Grok 4.20 Reasoning when...
- -Cost matters: 38% cheaper on input tokens
- -You need a larger context window (1,000K vs 922K)
At scale
Cost at scale
Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5.6 Terra
Grok 4.20 Reasoning
100K tokens
$0.50
$0.16Cheaper
1M tokens
$8.20
$3.25Cheaper
10M tokens
$82.00
$32.50Cheaper
FAQ
When should I use GPT 5.6 Terra instead of Grok 4.20 Reasoning?
GPT 5.6 Terra and Grok 4.20 Reasoning perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is Grok 4.20 Reasoning cheaper than GPT 5.6 Terra?
Yes. Grok 4.20 Reasoning input costs $1.25/MTok vs $2.00/MTok for GPT 5.6 Terra, saving 38% on input.
What are the context window sizes for GPT 5.6 Terra and Grok 4.20 Reasoning?
GPT 5.6 Terra has a 922K token context window. Grok 4.20 Reasoning has a 1,000K token context window.
Go deeper on either model
Per-call cost calculators, provider lineups, and price history for both models on this page.
Other comparisons
How GPT 5.6 Terra and Grok 4.20 Reasoning stack up against the rest of the field.
Track your real costs
Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.