tokevenGPTvsGrok
o3 vs Grok 4.20 Reasoning
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
o3
Mid-tierGrok 4.20 Reasoning
Mid-tierInput $/MTok
$2.00
$1.25
Output $/MTok
$8.00
$2.50
Cache discount
75% off
84% off
Context
200K
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
o3
Grok 4.20 Reasoning
Guidance
When to use o3 vs Grok 4.20 Reasoning
Choose o3 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 200K)
At scale
Cost at scale
Estimated cost assuming a seventy percent input and thirty percent output token split.
o3
Grok 4.20 Reasoning
100K tokens
$0.38
$0.16Cheaper
1M tokens
$3.80
$3.25Cheaper
10M tokens
$38.00
$32.50Cheaper
FAQ
When should I use o3 instead of Grok 4.20 Reasoning?
o3 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 o3?
Yes. Grok 4.20 Reasoning input costs $1.25/MTok vs $2.00/MTok for o3, saving 38% on input.
What are the context window sizes for o3 and Grok 4.20 Reasoning?
o3 has a 200K 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 o3 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.