Grok-3 vs Grok-4 Heavy
Grok-4 Heavy leads the LLM Stats Score 40.7 to 30.4.
xAI · xAI · Updated for 2026
Which is better?
Grok-4 Heavy leads the overall LLM Stats Score 40.7 to 30.4, ranking #54 overall.
In the 3 individual benchmarks reported for both models, Grok-4 Heavy wins 3; this is a narrower head-to-head signal than the composite indexes.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Grok-3
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose Grok-4 Heavy
- overall performance matters — it scores 40.7 and ranks #54 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
5 reported for Grok-3 · 6 for Grok-4 Heavy
Grok-3 outperforms in 0 benchmarks, while Grok-4 Heavy is better at 2 benchmarks (AIME 2025, GPQA).
Grok-4 Heavy shows notably better performance in the majority of benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Only Grok-3 specifies input context (128,000 tokens). Only Grok-3 specifies output context (8,000 tokens).
Input capabilities
Documented input modalities across available providers
Both Grok-3 and Grok-4 Heavy support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Grok-3
Grok-4 Heavy
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Grok-3 was released on 2025-02-17, while Grok-4 Heavy's release date is not specified.
We can confirm Grok-3's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.
Feb 17, 2025
1.6 years ago
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Knowledge Cutoff
When training data ends
Grok-3 has a knowledge cutoff of 2024-11-17, while Grok-4 Heavy has a cutoff of 2024-12-31.
Grok-4 Heavy has more recent training data (up to 2024-12-31), making it potentially better informed about events through that date compared to Grok-3 (2024-11-17).
Nov 2024
Dec 2024
1 mo newerOutputs Comparison
Judge for yourself.
Run your own prompts against Grok-3 and Grok-4 Heavy side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok-3 vs Grok-4 Heavy.