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Gemini 1.5 Flash vs Gemini 4 Carbon

Gemini 4 Carbon leads the LLM Stats Score 59.0 to 5.5.

Google · Google · Updated for 2026

Which is better?

Gemini 4 Carbon leads the overall LLM Stats Score 59.0 to 5.5, ranking #2 overall.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Gemini 1.5 Flash

  • you want predictable pricing at $0.15/M input and $0.60/M output

Choose Gemini 4 Carbon

  • overall performance matters — it scores 59.0 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you want the most recent training data — it shipped Oct 2026

At a glance

The differences that matter most.

Gemini 1.5 Flash
Google
Gemini 4 Carbon
Google
Core performance indexes
LLM Stats Score
5.5
#329
59.0
#2
Reasoning
5.2
#327
54.9
#5
Coding
-0.5
#277
48.1
#3
Cost, coverage & limits
Benchmark wins
—
—
Input price
$0.15 / M
— / M
Output price
$0.60 / M
— / M
Context window
1,048,576
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Gemini 1.5 Flash
Gemini 4 Carbon
Vision
5.3#178
36.0#12
Multimodal
8.8#143
38.0#6
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

22 reported for Gemini 1.5 Flash · 16 for Gemini 4 Carbon

No common benchmarks found

Gemini 1.5 Flash and Gemini 4 Carbondon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

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

Google
Gemini 1.5 Flash
Input1,048,576 tokens
Output8,192 tokens
Google
Gemini 4 Carbon
Input- tokens
Output- tokens
Thu Oct 29 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Gemini 1.5 Flash and Gemini 4 Carbon support multimodal inputs.

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

Gemini 1.5 Flash

Text
Images
Audio
Video

Gemini 4 Carbon

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

Proprietary

Closed source

Gemini 4 Carbon

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 1.5 Flash was released on 2024-05-01, while Gemini 4 Carbon was released on 2026-10-28.

Gemini 4 Carbon is 30 months newer than Gemini 1.5 Flash.

Gemini 1.5 Flash

May 1, 2024

2.5 years ago

Gemini 4 Carbon

Oct 28, 2026

-1 days ago

2.5yr newer

Knowledge Cutoff

When training data ends

Gemini 1.5 Flash has a documented knowledge cutoff of 2023-11-01, while Gemini 4 Carbon's cutoff date is not specified.

We can confirm Gemini 1.5 Flash's training data extends to 2023-11-01, but cannot make a direct comparison without Gemini 4 Carbon's cutoff date.

Gemini 1.5 Flash

Nov 2023

Gemini 4 Carbon

—

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

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

Gemini 1.5 Flash
✓ Preferred
Gemini 4 Carbon
Open in Playground

FAQ

Common questions about Gemini 1.5 Flash vs Gemini 4 Carbon.

Which is better, Gemini 1.5 Flash or Gemini 4 Carbon?

Gemini 4 Carbon leads the LLM Stats Score 59.0 to 5.5. Gemini 1.5 Flash is made by Google and Gemini 4 Carbon is made by Google. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 1.5 Flash compare to Gemini 4 Carbon in benchmarks?

Gemini 1.5 Flash scores XSTest: 97.0%, FLEURS: 90.4%, HellaSwag: 86.5%, GSM8k: 86.2%, BIG-Bench Hard: 85.5%. Gemini 4 Carbon scores Gray Swan IPI Benchmark: 100.0%, Vending-Bench 2: 100.0%, Graphwalks BFS >128k: 96.2%, WebDev Arena: 88.4%, SEC-bench Pro: 88.2%.

What are the context window sizes for Gemini 1.5 Flash and Gemini 4 Carbon?

Gemini 1.5 Flash supports 1.0M tokens and Gemini 4 Carbon 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 and Gemini 4 Carbon?

Key differences include LLM Stats Score (5.5 vs 59.0). See the full comparison above for benchmark-by-benchmark results.

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