tokevenGPTvsGrok
GPT 5 Nano 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 Nano
Fast / BudgetGrok 4.20 Reasoning
Mid-tierInput $/MTok
$0.05
$1.25
Output $/MTok
$0.40
$2.50
Cache discount
90% off
84% off
Context
272K
1,000K
Quality
Task confidence comparison
Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
0
vs
0
Code Review
0
vs
0
Summarization
0
vs
0
Q&A
0
vs
0
Extraction
0
vs
0
Reasoning
0
vs
0
Classification
0
vs
0
Creative Writing
0
vs
0
GPT 5 Nano
Grok 4.20 Reasoning
Guidance
When to use GPT 5 Nano vs Grok 4.20 Reasoning
Choose GPT 5 Nano when...
- -Cost matters: 96% cheaper on input tokens
Choose Grok 4.20 Reasoning when...
- -You need a larger context window (1,000K vs 272K)
- Similar performance; consider provider preference or ecosystem fit.
At scale
Cost at scale
Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5 Nano
Grok 4.20 Reasoning
100K tokens
$0.02Cheaper
$0.16
1M tokens
$0.15Cheaper
$3.25
10M tokens
$1.55Cheaper
$32.50
FAQ
When should I use GPT 5 Nano instead of Grok 4.20 Reasoning?
GPT 5 Nano 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 Nano?
Grok 4.20 Reasoning input costs $1.25/MTok, which is 2400% more than GPT 5 Nano at $0.05/MTok.
What are the context window sizes for GPT 5 Nano and Grok 4.20 Reasoning?
GPT 5 Nano has a 272K 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 Nano 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.