Grok 4.20 (Reasoning) pricing & specs

xAI · released 2026-03-09 · ● verified 2026-10-11

input / 1M$1.25
output / 1M$2.50
context1M
max output30K

// price history ($/1M tokens)

$6.90
input $/1Moutput $/1M2026-03-21 → 2026-10-11

// cheaper or similar alternatives

modelinoutctxvs Grok 4.20 (Reasoning)
Gemini 2.5 Flash-Lite$0.10$0.401.05M−88.8%
Claude Haiku 5.5$0.10$0.501M−87.2%
GPT-6 Luna$0.10$0.501.05M−87.2%
GLM-5.3-Flash$0.15$0.501M−84.8%
GPT-5.6 Luna$0.20$1.201.05M−71.2%

// price by host

hostin $/1Mout $/1M
Google Vertex AI$1.25$2.50

// faq

How much does Grok 4.20 (Reasoning) cost?

Grok 4.20 (Reasoning) costs $1.25 per million input tokens and $2.50 per million output tokens. At 50M input and 10M output tokens per month that is about $87.50. Prompts above 200K tokens are billed at $2.50 input and $5.00 output.

What is the context window of Grok 4.20 (Reasoning)?

1M tokens, with up to 30K output tokens per request.

Does Grok 4.20 (Reasoning) support prompt caching?

Yes. Cached input tokens cost $0.20 per million.

What are cheaper alternatives to Grok 4.20 (Reasoning)?

Gemini 2.5 Flash-Lite ($0.10 in / $0.40 out), Claude Haiku 5.5 ($0.10 in / $0.50 out), GPT-6 Luna ($0.10 in / $0.50 out) offer the same input types and capabilities for less.

// spec sheet

input / 1M
$1.25
output / 1M
$2.50
cache read / 1M
$0.20
> 200K ctx
$2.50 / $5.00
blended (3:1)
$1.5625
context
1M
max output
30K
input types
text · image · pdf
reasoning
yes
tool calling
yes
structured output
yes
open weights
no
knowledge cutoff
n/a
price source
xAI

report a data error

// cost calculator

modelin $/1Mout $/1M= monthly
Gemini 2.5 Flash-Lite$0.10$0.40$9.00
Claude Haiku 5.5$0.10$0.50$10.00
GPT-6 Luna$0.10$0.50$10.00
Grok 4.20 (Reasoning)$1.25$2.50$87.50

Base-tier list prices. Long-context tiers, caching and batch discounts are not included.