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DeepSeek-V4-Flash-0731 vs GPT-5.6 Luna

DeepSeek-V4-Flash-0731 and GPT-5.6 Luna are closely matched at 44.7 and 45.1 on the LLM Stats Score. DeepSeek-V4-Flash-0731 is 5.0x cheaper per token.

DeepSeek · OpenAI · Updated for 2026

Which is better?

DeepSeek-V4-Flash-0731 and GPT-5.6 Luna are closely matched on the overall LLM Stats Score at 44.7 and 45.1.

In the 5 individual benchmarks reported for both models, GPT-5.6 Luna wins 3; this is a narrower head-to-head signal than the composite indexes.

On price, DeepSeek-V4-Flash-0731 is roughly 5.0x 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.

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

Choose DeepSeek-V4-Flash-0731

  • cost matters — it's about 5.0x cheaper per token
  • you want the most recent training data — it shipped Jul 2026
  • you need open weights you can self-host or fine-tune

Choose GPT-5.6 Luna

  • you value its reported benchmark strengths — it wins 3 of 5 exact shared results
  • you process long inputs — it offers a 1,050,000 token context window

At a glance

The differences that matter most.

Core performance indexes
44.7
#35
45.1
#31
42.3
#45
44.2
#36
33.0
#36
36.3
#21
31.2
#30
31.7
#28
Cost, coverage & limits
Benchmark wins
2 of 5
3 of 5
Input price
$0.06 / M
$0.20 / M
Output price
$0.18 / M
$1.20 / M
Context window
1,048,576
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
DeepSeek-V4-Flash-0731
GPT-5.6 Luna
25.9#30
25.9#32
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for DeepSeek-V4-Flash-0731 · 45 for GPT-5.6 Luna

5 shared

DeepSeek-V4-Flash-0731 outperforms in 2 benchmarks (AutomationBench, Toolathlon), while GPT-5.6 Luna is better at 3 benchmarks (Agents' Last Exam, DeepSWE, Terminal-Bench 2.1).

GPT-5.6 Luna has a slight edge in benchmark performance.

Sat Sep 12 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

DeepSeek-V4-Flash-0731 costs less

For input processing, DeepSeek-V4-Flash-0731 ($0.06/1M tokens) is 3.3x cheaper than GPT-5.6 Luna ($0.20/1M tokens).

For output processing, DeepSeek-V4-Flash-0731 ($0.18/1M tokens) is 6.7x cheaper than GPT-5.6 Luna ($1.20/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than DeepSeek-V4-Flash-0731.*

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

Lowest available price from all providers
Sat Sep 12 2026 • llm-stats.com
DeepSeek
DeepSeek-V4-Flash-0731
Input tokens$0.06
Output tokens$0.18
Best providerDeepinfra
OpenAI
GPT-5.6 Luna
Input tokens$0.20
Output tokens$1.20
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 DeepSeek-V4-Flash-0731's 1,048,576 tokens. DeepSeek-V4-Flash-0731 can generate longer responses up to 1,048,576 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.

DeepSeek
DeepSeek-V4-Flash-0731
Input1,048,576 tokens
Output1,048,576 tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Sat Sep 12 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.6 Luna supports multimodal inputs, whereas DeepSeek-V4-Flash-0731 does not.

GPT-5.6 Luna can handle both text and other forms of data like images, making it suitable for multimodal applications.

DeepSeek-V4-Flash-0731

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

DeepSeek-V4-Flash-0731 is licensed under MIT, while GPT-5.6 Luna uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

DeepSeek-V4-Flash-0731

MIT

Open weights

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V4-Flash-0731 was released on 2026-07-31, while GPT-5.6 Luna was released on 2026-07-09.

DeepSeek-V4-Flash-0731 is 1 month newer than GPT-5.6 Luna.

DeepSeek-V4-Flash-0731

Jul 31, 2026

1 months ago

3w newer
GPT-5.6 Luna

Jul 9, 2026

2 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while DeepSeek-V4-Flash-0731's cutoff date is not specified.

We can confirm GPT-5.6 Luna's training data extends to 2026-02-16, but cannot make a direct comparison without DeepSeek-V4-Flash-0731's cutoff date.

DeepSeek-V4-Flash-0731

GPT-5.6 Luna

Feb 2026

Provider Availability

DeepSeek-V4-Flash-0731 is available from DeepInfra, Novita, Fireworks. GPT-5.6 Luna is available from OpenAI.

DeepSeek-V4-Flash-0731

deepinfra logo
Deepinfra
Input Price:Input: $0.06/1MOutput Price:Output: $0.18/1M
novita logo
Novita
Input Price:Input: $0.14/1MOutput Price:Output: $0.28/1M
fireworks logo
Fireworks
Input Price:Input: $0.44/1MOutput Price:Output: $1.32/1M

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against DeepSeek-V4-Flash-0731 and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

DeepSeek-V4-Flash-0731
✓ Preferred
GPT-5.6 Luna
Open in Playground

FAQ

Common questions about DeepSeek-V4-Flash-0731 vs GPT-5.6 Luna.

Which is better, DeepSeek-V4-Flash-0731 or GPT-5.6 Luna?

DeepSeek-V4-Flash-0731 and GPT-5.6 Luna are closely matched on the LLM Stats Score at 44.7 and 45.1. DeepSeek-V4-Flash-0731 is made by DeepSeek and GPT-5.6 Luna is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does DeepSeek-V4-Flash-0731 compare to GPT-5.6 Luna in benchmarks?

DeepSeek-V4-Flash-0731 scores Terminal-Bench 2.1: 82.7%, CyberGym: 76.7%, Toolathlon: 70.3%, DSBench-FullStack: 68.7%, DSBench-Hard: 59.6%. 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 DeepSeek-V4-Flash-0731 cheaper than GPT-5.6 Luna?

DeepSeek-V4-Flash-0731 is 3.3x cheaper for input tokens. DeepSeek-V4-Flash-0731 costs $0.06/M input and $0.18/M output via deepinfra. GPT-5.6 Luna costs $0.20/M input and $1.20/M output via openai.

What are the context window sizes for DeepSeek-V4-Flash-0731 and GPT-5.6 Luna?

DeepSeek-V4-Flash-0731 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 DeepSeek-V4-Flash-0731 and GPT-5.6 Luna?

Key differences include LLM Stats Score (44.7 vs 45.1), context window (1.0M vs 1.1M), input pricing ($0.06 vs $0.20/M), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes DeepSeek-V4-Flash-0731 and GPT-5.6 Luna?

DeepSeek-V4-Flash-0731 is developed by DeepSeek and GPT-5.6 Luna is developed by OpenAI.