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Gemini 2.5 Flash vs GPT-5.6 Luna

Gemini 2.5 Flash

Google

79#98
vs
GPT-5.6 Luna

OpenAI

89#34
Signal-by-Signal Comparison
SignalGemini 2.5 FlashDeltaGPT-5.6 Luna
Capabilities
100
--
100
Benchmarks
81
-7
88
Pricing
98
-2
99
Context window size
96
0
96
Recency
57
-43
100
Output Capacity
80
-5
85
Overall Result
0 wins
of 6
5 wins
GPT-5.6 Luna wins 5 of 6 signals

Score History

Score History (25 data points)
Gemini 2.5 FlashGPT-5.6 Luna
Gemini 2.5 Flash

79.1

current score

Leader

GPT-5.6 Luna

right now

GPT-5.6 Luna

89

current score

LMMarketCap.com
Interactive Price Comparison
100Kcalls/month
1,000tokens (~1,333 chars)
500tokens (~667 chars)

Gemini 2.5 Flash

Google

Per request$0.001550
Daily$5.17
Monthly$155.00
Annual$1860.00

GPT-5.6 Luna

OpenAI

Best Value
Per request$0.000400
Daily$1.33
Monthly$40.00
Annual$480.00

GPT-5.6 Luna saves you $115.00/month

That's $1380.00/year compared to Gemini 2.5 Flash at your current usage level of 100K calls/month.

74% cheaper
Choose GPT-5.6 Luna for cost optimization

Gemini 2.5 Flash pricing:
Input:$0.30/M tokens
Output:$2.50/M tokens
GPT-5.6 Luna pricing:
Input:$0.10/M tokens
Output:$0.60/M tokens
Gemini 2.5 Flash

Google

79

Composite Score

Winner
GPT-5.6 Luna

OpenAI

89

Composite Score

Signal-by-Signal Comparison
MetricGemini 2.5 FlashGPT-5.6 LunaWinner
Overall Score
79
89
GPT-5.6 Luna
Rank#98#34
GPT-5.6 Luna
Quality Rank#98#34
GPT-5.6 Luna
Adoption Rank#98#34
GPT-5.6 Luna
Parameters------
Context Window1049K1050K
GPT-5.6 Luna
Pricing$0.30/$2.50/M$0.10/$0.60/M--
Signal Scores
Capabilities
100
100
Gemini 2.5 Flash
Benchmarks
81
88
GPT-5.6 Luna
Pricing
98
99
GPT-5.6 Luna
Context window size
96
96
GPT-5.6 Luna
Recency
57
100
GPT-5.6 Luna
Output Capacity
80
85
GPT-5.6 Luna
Benchmark Head-to-Head(12 benchmarks)
Gemini 2.5: 0GPT-5.6 Luna: 11
Gemini 2.5
GPT-5.6 Luna
Normalized 0-100%
MMLU
85.8%93%
MMLU-Pro
78%84.5%
GPQA Diamond
82.8%85%
MATH-500
85.8%92.5%
HumanEval
90%96.5%
SWE-bench Verified
60.4%75%
AIME 2024
88%-
IFEval
85.5%92%
BBH
85%90.5%
Arena Elo
13951465
LiveBench
66.5%76%
HLE
12.08%35%
Benchmark Interpretation

Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.

Gemini 2.5 FlashStrong Performer

Scores 79/100 (rank #98), placing it in the top 67% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
GPT-5.6 LunaElite Tier

Scores 89/100 (rank #34), placing it in the top 89% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

GPT-5.6 Luna has a 10-point advantage, which typically translates to noticeably better performance on complex reasoning, code generation, and multi-step tasks.

When to Use Each Model

Choose Gemini 2.5 Flash when you need:

  • Step-by-step reasoning and chain-of-thought problem solving

Choose GPT-5.6 Luna when you need:

  • High-volume production workloads where API costs must be minimized
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
Gemini 2.5 Flash
Input cost$0.30/M tokens
Output cost$2.50/M tokens
Cost per quality point$0.035
Est. monthly (1M tokens/day)$42.00
GPT-5.6 LunaBest Value
Input cost$0.10/M tokens
Output cost$0.60/M tokens
Cost per quality point$0.008
Est. monthly (1M tokens/day)$10.50

GPT-5.6 Luna offers 75% better value per quality point. At 1M tokens/day, you'd spend $10.50/month with GPT-5.6 Luna vs $42.00/month with Gemini 2.5 Flash - a $31.50 monthly difference.

Latency & Speed
Gemini 2.5 FlashFaster
Speed score0/100
GPT-5.6 Luna
Speed score0/100

Both models have comparable response speeds. For most applications, the latency difference is negligible.

When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.

Example Use Cases

Code generation & review

Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring

Gemini 2.5 Flash

Customer support chatbot

Suitable for user-facing chat with competitive response times. GPT-5.6 Luna also offers lower per-token costs for high-volume support

Gemini 2.5 Flash

Long document analysis

Larger context window (1050K tokens) can process longer documents, contracts, and research papers in a single pass

GPT-5.6 Luna

Batch data extraction

Lower output pricing ($0.60/M) reduces costs when processing thousands of records daily

GPT-5.6 Luna

Creative writing & content

Higher overall composite score (89/100) correlates with better nuance, coherence, and style in long-form content

GPT-5.6 Luna

Image understanding & OCR

Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly

Gemini 2.5 Flash
Which Should You Choose?
Our recommendation:
GPT-5.6 Luna

GPT-5.6 Luna has a moderate advantage with a 9.900000000000006-point lead in composite score. It wins on more signal dimensions, but Gemini 2.5 Flash has specific strengths that could make it the better choice for certain workflows.

by Google

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Reliability - Higher uptime and faster response speeds
  • Choose for Prototyping - Stronger community support and better developer experience
  • Choose for Production - Wider enterprise adoption and proven at scale
GPT-5.6 Luna
Recommended

by OpenAI

  • Choose for Cost - 75% lower pricing; better value at scale
Capability Comparison
CapabilityGemini 2.5 FlashGPT-5.6 Luna
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoning
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

Gemini 2.5 Flash

Google

$3.54
estimated monthly cost

GPT-5.6 Luna

OpenAI

Best Value
$0.9000
estimated monthly cost

GPT-5.6 Luna saves you $2.64/month

That's 75% cheaper than Gemini 2.5 Flash at 1,000 tokens/request and 100 requests/day.

Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.

Parameters & Context
ParameterGemini 2.5 FlashGPT-5.6 Luna
Context Window1.0M1.1M
Max Output Tokens65,535128,000
Open SourceNoNo
CreatedJun 17, 2025Jul 9, 2026
Last updated: 36m ago

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