Grok
Grok

Grok 4.20 (Reasoning)

Model ID:grok-4.20-0309-reasoning
2026-03-31Proprietary Model
Grok SuperGrok Heavy|API
PopularityNo.4

Grok 4.20 is xAI's newest flagship model with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering consistently precise and truthful responses. Reasoning can be enabled/disabled using the `reasoning` `enabled` parameter in the API. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)

Knowledge Cutoff
2025-09-01

The date this AI finished learning. It may not know about things that happened after this date.

Input → Output Format

The types of content this AI can receive, and what it can produce in return.

Context Memory
2M

The maximum amount of text the AI can read and process in a single request. A larger number means it can handle longer documents or conversations.

Cost/1M Words
$2IN$6OUT

The cost of using this AI directly in your own application. Shown in USD per 1 million units of text (tokens).

AI Performance Evaluation

Arena Overall Score
1491
±7
As of 2026-04-02
Overall Rank
No.4
7,383 Votes
Arena by Ability
Hard Prompts
1506±10No.5
Expert Knowledge
1483±27No.24
Instruction Following
1467±14No.10
Conversation Memory
1508±21🥉 No.3
Creative
1485±19No.4
Coding
1526±15No.6
Math
1456±25No.21
Arena by Occupation
Creative Writing
1472±15No.6
Social Sciences
1488±18No.8
Media
1471±17🥉 No.3
Business
1489±17No.4
Healthcare
1528±28🥈 No.2
Legal
1518±27🥇 No.1
Software
1519±12No.4
Mathematics
1472±32No.14
Speed
Standard Mode
131tok/sec↑53
First Output 0.59s
Artificial Analysis