Grok 4 Fast vs LongCat-Flash-Thinking
Grok 4 Fast and LongCat-Flash-Thinking are closely matched at 32.0 and 28.8 on the LLM Stats Score. Grok 4 Fast is 1.9x cheaper per token.
xAI · Meituan · Updated for 2026
Which is better?
Grok 4 Fast and LongCat-Flash-Thinking are closely matched on the overall LLM Stats Score at 32.0 and 28.8.
In the 3 individual benchmarks reported for both models, Grok 4 Fast wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Grok 4 Fast is roughly 1.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok 4 Fast also accepts a larger context window (2,000,000 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 Grok 4 Fast
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- cost matters — it's about 1.9x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
Choose LongCat-Flash-Thinking
- you want the most recent training data — it shipped Sep 2025
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
7 reported for Grok 4 Fast · 14 for LongCat-Flash-Thinking
Grok 4 Fast outperforms in 3 benchmarks (AIME 2025, GPQA, LiveCodeBench), while LongCat-Flash-Thinking is better at 0 benchmarks.
Grok 4 Fast significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Grok 4 Fast ($0.20/1M tokens) is 1.5x cheaper than LongCat-Flash-Thinking ($0.30/1M tokens).
For output processing, Grok 4 Fast ($0.50/1M tokens) is 2.4x cheaper than LongCat-Flash-Thinking ($1.20/1M tokens).
In conclusion, LongCat-Flash-Thinking is more expensive than Grok 4 Fast.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok 4 Fast accepts 2,000,000 input tokens compared to LongCat-Flash-Thinking's 128,000 tokens. LongCat-Flash-Thinking can generate longer responses up to 128,000 tokens, while Grok 4 Fast is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Grok 4 Fast supports multimodal inputs, whereas LongCat-Flash-Thinking does not.
Grok 4 Fast can handle both text and other forms of data like images, making it suitable for multimodal applications.
Grok 4 Fast
LongCat-Flash-Thinking
License
Usage and distribution terms
Grok 4 Fast is licensed under a proprietary license, while LongCat-Flash-Thinking uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Grok 4 Fast was released on 2025-08-28, while LongCat-Flash-Thinking was released on 2025-09-22.
LongCat-Flash-Thinking is 1 month newer than Grok 4 Fast.
Aug 28, 2025
1.0 years ago
Sep 22, 2025
11 months ago
3w newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Grok 4 Fast is available from xAI. LongCat-Flash-Thinking is available from Meituan.
Grok 4 Fast
LongCat-Flash-Thinking
Outputs Comparison
Judge for yourself.
Run your own prompts against Grok 4 Fast and LongCat-Flash-Thinking side-by-side, then vote on the output you prefer.
FAQ
Common questions about Grok 4 Fast vs LongCat-Flash-Thinking.