The AI arena is free today

Open Superagent

Claude Mythos 5.1 vs LongCat-2.5

Claude Mythos 5.1 and LongCat-2.5 are closely matched at 44.1 and 50.0 on the LLM Stats Score. LongCat-2.5 is 38.1x cheaper per token.

Anthropic · Meituan · Updated for 2026

Which is better?

Claude Mythos 5.1 and LongCat-2.5 are closely matched on the overall LLM Stats Score at 44.1 and 50.0.

In the 1 individual benchmarks reported for both models, Claude Mythos 5.1 wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, LongCat-2.5 is roughly 38.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

LongCat-2.5 also accepts a larger context window (1,048,576 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 Claude Mythos 5.1

  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results

Choose LongCat-2.5

  • cost matters — it's about 38.1x cheaper per token
  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Nov 2026

At a glance

The differences that matter most.

Claude Mythos 5.1
Anthropic
LongCat-2.5
Meituan
Core performance indexes
LLM Stats Score
44.1
#53
50.0
#20
Reasoning
42.8
#57
48.3
#21
Coding
36.5
#34
38.6
#27
Agents
34.6
#34
36.3
#23
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$10.00 / M
$0.30 / M
Output price
$50.00 / M
$1.20 / M
Context window
1,000,000
1,048,576

Individual benchmarks

1 reported for Claude Mythos 5.1 · 23 for LongCat-2.5

1 shared

Claude Mythos 5.1 outperforms in 1 benchmarks (Terminal-Bench 4.0), while LongCat-2.5 is better at 0 benchmarks.

Claude Mythos 5.1 significantly outperforms across most benchmarks.

Sun Nov 08 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

LongCat-2.5 costs less

For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 33.3x more expensive than LongCat-2.5 ($0.30/1M tokens).

For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 41.7x more expensive than LongCat-2.5 ($1.20/1M tokens).

In conclusion, Claude Mythos 5.1 is more expensive than LongCat-2.5.*

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

Lowest available price from all providers
Sun Nov 08 2026 • llm-stats.com
Anthropic
Claude Mythos 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Meituan
LongCat-2.5
Input tokens$0.30
Output tokens$1.20
Best providerMeituan
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

LongCat-2.5 accepts 1,048,576 input tokens compared to Claude Mythos 5.1's 1,000,000 tokens. LongCat-2.5 can generate longer responses up to 131,072 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.

Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
Meituan
LongCat-2.5
Input1,048,576 tokens
Output131,072 tokens
Sun Nov 08 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Mythos 5.1 and LongCat-2.5 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Mythos 5.1

Text
Images
Audio
Video

LongCat-2.5

Text
Images
Audio
Video

Release Timeline

When each model was launched

Claude Mythos 5.1 was released on 2026-09-01, while LongCat-2.5 was released on 2026-11-01.

LongCat-2.5 is 2 months newer than Claude Mythos 5.1.

Claude Mythos 5.1

Sep 1, 2026

2 months ago

LongCat-2.5

Nov 1, 2026

6 days ago

2mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Mythos 5.1 is available from Anthropic. LongCat-2.5 is available from Meituan.

Claude Mythos 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

LongCat-2.5

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?

Judge for yourself.

Run your own prompts against Claude Mythos 5.1 and LongCat-2.5 side-by-side, then vote on the output you prefer.

Claude Mythos 5.1
✓ Preferred
LongCat-2.5
Open in Playground

FAQ

Common questions about Claude Mythos 5.1 vs LongCat-2.5.

Which is better, Claude Mythos 5.1 or LongCat-2.5?

Claude Mythos 5.1 and LongCat-2.5 are closely matched on the LLM Stats Score at 44.1 and 50.0. Claude Mythos 5.1 is made by Anthropic and LongCat-2.5 is made by Meituan. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.1 compare to LongCat-2.5 in benchmarks?

Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%. LongCat-2.5 scores MathVision: 96.5%, BrowseComp: 91.9%, CharXiv-R: 90.2%, Terminal-Bench 2.1: 88.4%, Video-MME: 85.2%.

Is Claude Mythos 5.1 cheaper than LongCat-2.5?

LongCat-2.5 is 33.3x cheaper for input tokens. Claude Mythos 5.1 costs $10.00/M input and $50.00/M output via anthropic. LongCat-2.5 costs $0.30/M input and $1.20/M output via meituan.

What are the context window sizes for Claude Mythos 5.1 and LongCat-2.5?

Claude Mythos 5.1 supports 1.0M tokens and LongCat-2.5 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos 5.1 and LongCat-2.5?

Key differences include LLM Stats Score (44.1 vs 50.0), context window (1.0M vs 1.0M), input pricing ($10.00 vs $0.30/M), licensing (Proprietary vs Unknown). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.1 and LongCat-2.5?

Claude Mythos 5.1 is developed by Anthropic and LongCat-2.5 is developed by Meituan.

Related comparisons