Model Comparison

Gemini 1.5 Flash 8B vs GPT-5.6 LunaWhich is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks. Gemini 1.5 Flash 8B is 17.6x cheaper per token.

Verdict: Gemini 1.5 Flash 8B vs GPT-5.6 Luna — which is better?

Gemini 1.5 Flash 8B (by Google) and GPT-5.6 Luna (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 1.5 Flash 8B outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 1 benchmark (GPQA). GPT-5.6 Luna significantly outperforms across most benchmarks.

On price, Gemini 1.5 Flash 8B is roughly 17.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.6 Luna also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 1.5 Flash 8B if…

  • cost matters — it's about 17.6x cheaper per token

Choose GPT-5.6 Luna if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Gemini 1.5 Flash 8B outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 1 benchmark (GPQA).

GPT-5.6 Luna significantly outperforms across most benchmarks.

Sat Jul 18 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Gemini 1.5 Flash 8B costs less

For input processing, Gemini 1.5 Flash 8B ($0.07/1M tokens) is 14.3x cheaper than GPT-5.6 Luna ($1.00/1M tokens).

For output processing, Gemini 1.5 Flash 8B ($0.30/1M tokens) is 20.0x cheaper than GPT-5.6 Luna ($6.00/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than Gemini 1.5 Flash 8B.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sat Jul 18 2026 • llm-stats.com
Google
Gemini 1.5 Flash 8B
Input tokens$0.07
Output tokens$0.30
Best providerGoogle
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.6 Luna accepts 1,050,000 input tokens compared to Gemini 1.5 Flash 8B's 1,048,576 tokens. GPT-5.6 Luna can generate longer responses up to 128,000 tokens, while Gemini 1.5 Flash 8B is limited to 8,192 tokens.

Google
Gemini 1.5 Flash 8B
Input1,048,576 tokens
Output8,192 tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Sat Jul 18 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 1.5 Flash 8B and GPT-5.6 Luna 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

GPT-5.6 Luna

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

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 1.5 Flash 8B was released on 2024-03-15, while GPT-5.6 Luna was released on 2026-07-09.

GPT-5.6 Luna is 28 months newer than Gemini 1.5 Flash 8B.

Gemini 1.5 Flash 8B

Mar 15, 2024

2.3 years ago

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

2.3yr newer

Knowledge Cutoff

When training data ends

Gemini 1.5 Flash 8B has a knowledge cutoff of 2024-10-01, while GPT-5.6 Luna has a cutoff of 2026-02-16.

GPT-5.6 Luna has more recent training data (up to 2026-02-16), 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

GPT-5.6 Luna

Feb 2026

1.3 yr newer

Provider Availability

Gemini 1.5 Flash 8B is available from Google. GPT-5.6 Luna is available from OpenAI.

Gemini 1.5 Flash 8B

google logo
Google
Input Price:Input: $0.07/1MOutput Price:Output: $0.30/1M

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Less expensive input tokens
Less expensive output tokens
OpenAI
Larger context window (1,050,000 tokens)
Higher GPQA score (92.3% vs 38.4%)
GoogleGemini 1.5 Flash 8B
OpenAIGPT-5.6 Luna
Compare in Playground

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 1.5 Flash 8B and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

Gemini 1.5 Flash 8B
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 1.5 Flash 8B
OpenAI
GPT-5.6 Luna

FAQ

Common questions about Gemini 1.5 Flash 8B vs GPT-5.6 Luna.

Which is better, Gemini 1.5 Flash 8B or GPT-5.6 Luna?

GPT-5.6 Luna significantly outperforms across most benchmarks. Gemini 1.5 Flash 8B is made by Google and GPT-5.6 Luna is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 1.5 Flash 8B compare to GPT-5.6 Luna in benchmarks?

Gemini 1.5 Flash 8B scores XSTest: 92.6%, FLEURS: 86.4%, Natural2Code: 75.5%, WMT23: 72.6%, Video-MME: 66.2%. GPT-5.6 Luna scores Connectors: 99.9%, HealthBench Consensus: 95.1%, GPQA: 92.3%, Search and Function-Calling: 89.7%, Capture-the-Flag Challenges (Internal): 85.2%.

Is Gemini 1.5 Flash 8B cheaper than GPT-5.6 Luna?

Gemini 1.5 Flash 8B is 14.3x cheaper for input tokens. Gemini 1.5 Flash 8B costs $0.07/M input and $0.30/M output via google. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai.

What are the context window sizes for Gemini 1.5 Flash 8B and GPT-5.6 Luna?

Gemini 1.5 Flash 8B supports 1.0M tokens and GPT-5.6 Luna supports 1.1M 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 GPT-5.6 Luna?

Key differences include context window (1.0M vs 1.1M), input pricing ($0.07 vs $1.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 1.5 Flash 8B and GPT-5.6 Luna?

Gemini 1.5 Flash 8B is developed by Google and GPT-5.6 Luna is developed by OpenAI.

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