Model Comparison

GPT-5.6 Luna vs LongCat-Flash-ChatWhich is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks. LongCat-Flash-Chat is 4.3x cheaper per token.

Verdict: GPT-5.6 Luna vs LongCat-Flash-Chat — which is better?

GPT-5.6 Luna (by OpenAI) and LongCat-Flash-Chat (by Meituan) 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.

GPT-5.6 Luna outperforms in 1 benchmarks (GPQA), while LongCat-Flash-Chat is better at 0 benchmarks. GPT-5.6 Luna significantly outperforms across most benchmarks.

On price, LongCat-Flash-Chat is roughly 4.3x 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 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

Choose LongCat-Flash-Chat if…

  • cost matters — it's about 4.3x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT-5.6 Luna outperforms in 1 benchmarks (GPQA), while LongCat-Flash-Chat is better at 0 benchmarks.

GPT-5.6 Luna significantly outperforms across most benchmarks.

Tue Jul 21 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

LongCat-Flash-Chat costs less

For input processing, GPT-5.6 Luna ($1.00/1M tokens) is 3.3x more expensive than LongCat-Flash-Chat ($0.30/1M tokens).

For output processing, GPT-5.6 Luna ($6.00/1M tokens) is 5.0x more expensive than LongCat-Flash-Chat ($1.20/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than LongCat-Flash-Chat.*

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

Lowest available price from all providers
Tue Jul 21 2026 • llm-stats.com
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
Meituan
LongCat-Flash-Chat
Input tokens$0.30
Output tokens$1.20
Best providerMeituan
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 LongCat-Flash-Chat's 128,000 tokens. Both models can generate responses up to 128,000 tokens.

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Meituan
LongCat-Flash-Chat
Input128,000 tokens
Output128,000 tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.6 Luna supports multimodal inputs, whereas LongCat-Flash-Chat does not.

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

GPT-5.6 Luna

Text
Images
Audio
Video

LongCat-Flash-Chat

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while LongCat-Flash-Chat uses MIT.

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

GPT-5.6 Luna

Proprietary

Closed source

LongCat-Flash-Chat

MIT

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while LongCat-Flash-Chat was released on 2025-08-29.

GPT-5.6 Luna is 10 months newer than LongCat-Flash-Chat.

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

10mo newer
LongCat-Flash-Chat

Aug 29, 2025

10 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while LongCat-Flash-Chat'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 LongCat-Flash-Chat's cutoff date.

GPT-5.6 Luna

Feb 2026

LongCat-Flash-Chat

—

Provider Availability

GPT-5.6 Luna is available from OpenAI. LongCat-Flash-Chat is available from Meituan.

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $6.00/1M

LongCat-Flash-Chat

meituan logo
Meituan
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
Supports multimodal inputs
Higher GPQA score (92.3% vs 73.2%)
Meituan
Less expensive input tokens
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

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

GPT-5.6 Luna
✓ Preferred
LongCat-Flash-Chat
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Luna
Meituan
LongCat-Flash-Chat

FAQ

Common questions about GPT-5.6 Luna vs LongCat-Flash-Chat.

Which is better, GPT-5.6 Luna or LongCat-Flash-Chat?

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

How does GPT-5.6 Luna compare to LongCat-Flash-Chat in benchmarks?

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%. LongCat-Flash-Chat scores MATH-500: 96.4%, MMLU: 89.7%, IFEval: 89.6%, ZebraLogic: 89.3%, HumanEval: 88.4%.

Is GPT-5.6 Luna cheaper than LongCat-Flash-Chat?

LongCat-Flash-Chat is 3.3x cheaper for input tokens. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai. LongCat-Flash-Chat costs $0.30/M input and $1.20/M output via meituan.

What are the context window sizes for GPT-5.6 Luna and LongCat-Flash-Chat?

GPT-5.6 Luna supports 1.1M tokens and LongCat-Flash-Chat supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.6 Luna and LongCat-Flash-Chat?

Key differences include context window (1.1M vs 128K), input pricing ($1.00 vs $0.30/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and LongCat-Flash-Chat?

GPT-5.6 Luna is developed by OpenAI and LongCat-Flash-Chat is developed by Meituan.

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