GPT-5.6 Luna vs LongCat-2.0

Both models are evenly matched

Arena ELO

Tie

Cheaper

Tie

Faster

Tie

Detailed Comparison

Category	GPT-5.6 Luna	LongCat-2.0
Provider	OpenAI	Meituan
Context Window	128K	128K
Input Price ($/1M)	N/A	N/A
Output Price ($/1M)	N/A	N/A
Arena ELO	N/A	N/A
Coding	N/A	N/A
Reasoning	N/A	N/A
Speed (tokens/sec)	N/A	N/A
Open Source	No	Yes

Frequently Asked Questions

Which has a larger context window?

GPT-5.6 Luna supports 128K context, while LongCat-2.0 supports 128K.

Is GPT-5.6 Luna or LongCat-2.0 open source?

GPT-5.6 Luna is proprietary. LongCat-2.0 is open source.

Related Articles

OpenAI narrows GPT-5.6 rollout after U.S. request

GPT-5.6 rumors point to 2M context and coding gains

GPT-5.6 looks like a fix-and-upgrade release

What We Know About GPT-5.6's Release Date

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