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Gemini 1.5 Flash 8B vs Grok-4 Heavy

Grok-4 Heavy leads the LLM Stats Score 40.9 to -0.6.

Google · xAI · Updated for 2026

Which is better?

Grok-4 Heavy leads the overall LLM Stats Score 40.9 to -0.6, ranking #50 overall.

In the 1 individual benchmarks reported for both models, Grok-4 Heavy wins 1; 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 Gemini 1.5 Flash 8B

  • you want predictable pricing at $0.07/M input and $0.30/M output

Choose Grok-4 Heavy

  • overall performance matters — it scores 40.9 and ranks #50 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results

At a glance

The differences that matter most.

Gemini 1.5 Flash 8B
Google
Grok-4 Heavy
xAI
Core performance indexes
LLM Stats Score
-0.6
#319
40.9
#50
Reasoning
-0.3
#308
39.2
#53
Cost, coverage & limits
Benchmark wins
0 of 1
1 of 1
Input price
$0.07 / M
— / M
Output price
$0.30 / M
— / M
Context window
1,048,576
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Gemini 1.5 Flash 8B
Grok-4 Heavy
Math
2.7#284
41.4#6
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

13 reported for Gemini 1.5 Flash 8B · 6 for Grok-4 Heavy

1 shared

Gemini 1.5 Flash 8B outperforms in 0 benchmarks, while Grok-4 Heavy is better at 1 benchmark (GPQA).

Grok-4 Heavy significantly outperforms across most benchmarks.

Sun Sep 06 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Gemini 1.5 Flash 8B specifies input context (1,048,576 tokens). Only Gemini 1.5 Flash 8B specifies output context (8,192 tokens).

Google
Gemini 1.5 Flash 8B
Input1,048,576 tokens
Output8,192 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Sun Sep 06 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 1.5 Flash 8B and Grok-4 Heavy support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 1.5 Flash 8B

Text
Images
Audio
Video

Grok-4 Heavy

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 1.5 Flash 8B

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 1.5 Flash 8B was released on 2024-03-15, while Grok-4 Heavy's release date is not specified.

We can confirm Gemini 1.5 Flash 8B's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Gemini 1.5 Flash 8B

Mar 15, 2024

2.5 years ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Gemini 1.5 Flash 8B has a knowledge cutoff of 2024-10-01, 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 Gemini 1.5 Flash 8B (2024-10-01).

Gemini 1.5 Flash 8B

Oct 2024

Grok-4 Heavy

Dec 2024

2 mo newer

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Gemini 1.5 Flash 8B and Grok-4 Heavy side-by-side, then vote on the output you prefer.

Gemini 1.5 Flash 8B
✓ Preferred
Grok-4 Heavy
Open in Playground

FAQ

Common questions about Gemini 1.5 Flash 8B vs Grok-4 Heavy.

Which is better, Gemini 1.5 Flash 8B or Grok-4 Heavy?

Grok-4 Heavy leads the LLM Stats Score 40.9 to -0.6. Gemini 1.5 Flash 8B is made by Google and Grok-4 Heavy is made by xAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 1.5 Flash 8B compare to Grok-4 Heavy in benchmarks?

Gemini 1.5 Flash 8B scores XSTest: 92.6%, FLEURS: 86.4%, Natural2Code: 75.5%, WMT23: 72.6%, Video-MME: 66.2%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.

What are the context window sizes for Gemini 1.5 Flash 8B and Grok-4 Heavy?

Gemini 1.5 Flash 8B supports 1.0M tokens and Grok-4 Heavy supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 1.5 Flash 8B and Grok-4 Heavy?

Key differences include LLM Stats Score (-0.6 vs 40.9). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 1.5 Flash 8B and Grok-4 Heavy?

Gemini 1.5 Flash 8B is developed by Google and Grok-4 Heavy is developed by xAI.

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