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LongCat-2.5 Open Weights vs Kimi K3.1 Pro: MIT Wins

Meituan released LongCat-2.5, a 1.6-trillion-parameter mixture-of-experts model with roughly 48 billion active parameters per token, under the MIT licence on Hugging Face, adding native visual input and agentic coding to LongCat-2.0. The model card reports in-house gains such as Terminal Bench v2.1 rising from 70.8 to 88.4 and DeepSWE v1.1 from 9.7 to 64.6, though Meituan calls the unmarked scores indicative and the card places Claude Opus 5 at 89.1 and DeepSeek-V4.1-Flash at 90.6 on the same suite. The 3.56 TB checkpoint ships without a listed inference provider, with Meituan documenting an NPU serving route via SGLang-FluentLLM and GPU support awaiting community vLLM work.

by read6 min views2 publishedNov 14, 2026

On 10 November 2026 Meituan published the LongCat-2.5 open weights on Hugging Face under the MIT licence: a 1.6 trillion parameter mixture-of-experts model with about 48 billion parameters active per token, in a 3.56 TB repository. On licence terms it beats Kimi K3.1 Pro and Baidu's ERNIE 5.5 Flash Base, because neither revenue gates nor territory carve-outs apply. For most Indian developers and teams the sensible order is to rent the hosted API first, at roughly ₹28 per million input tokens (pricing), and self-host only if you already operate trillion-parameter MoE serving.

LongCat-2.5 builds on LongCat-2.0 and adds native visual input alongside agentic coding. According to the model card, vision comes from LongCat-Next, which turns native-resolution visual features into discrete tokens aligned with text. It is a hybrid model: thinking and non-thinking modes are switched per request with chat_template_kwargs: {enable_thinking: ...} in the OpenAI-compatible API.

Benchmark (model card, in-house) LongCat-2.0 LongCat-2.5
Terminal Bench v2.1 70.8 88.4
Terminal Bench v4.0 3.0 38.5
DeepSWE v1.1 9.7 64.6
BrowseComp 79.9 91.9
AutomationBench v1.0.6 15.8 51.8

Meituan states that unmarked scores are measured in-house and are indicative only, so treat the jumps as a direction rather than a guarantee. On the same card, Terminal Bench v2.1 puts Claude Opus 5 at 89.1 and DeepSeek-V4.1-Flash at 90.6, both cited from public reports, so LongCat-2.5 is close to the leaders rather than ahead. VentureBeat notes that the comparison set predates newer models, some of which post higher Terminal Bench v4.0 scores than LongCat's 38.5; even Claude Opus 5's cited 53.9 on that suite is well clear of the 38.5, per the model card comparison.

The large open-weights releases this November now differ more by licence than by capability. The LongCat LICENSE file is 1.06 kB and reads "Copyright (c) 2026 Meituan", with the model card confirming the weights are MIT.

Model Licence Main constraint
LongCat-2.5 (Meituan) MIT None beyond attribution; no trademark or patent grant
Kimi K3.1 Pro (Moonshot) Modified MIT Separate agreement above a revenue threshold for model-as-a-service use; see our Kimi K3.1 Pro write-up
ERNIE 5.5 Flash Base (Baidu) Custom Excludes the EU, UK and South Korea; commercial use needs notice or authorisation by revenue band

The Kimi and ERNIE rows come from third-party write-ups of their licence files, so read the originals before committing a product to either. If you are choosing a base model for a company, MIT removes a whole category of legal questions. For a comparison of two other recent releases, see Tencent HY4 vs Mistral Large 4.

The repository shows this command pattern:

hf download hf://meituan-longcat/LongCat-2.5

Expect 208 shards of roughly 17.2 GB each, plus an 8.12 MB index file. Check free disk before starting; the checkpoint alone is 3.56 TB, before any converted or quantised copies. The upgrade path from LongCat-2.0 is a straightforward swap of model path and chat-template flags, provided your serving stack supports the architecture.

That is the catch. Hugging Face lists no inference provider hosting the model, and Meituan's documented serving route is NPU platforms through SGLang-FluentLLM. GPU users should wait for community vLLM or SGLang support. Meituan reports W4A4 quantisation on expert weights, with 43.3% higher prefill throughput and 42.77% higher decode throughput than a W8A8 baseline, per the model card. Those figures describe Meituan's own stack, not what you will see on other hardware.

Rent first. The LongCat pricing page lists a limited-time discount of $0.30 per million uncached input tokens, $0.006 per million cached input tokens and $1.20 per million output tokens. Using the RBI reference rate of 94.86 rupees per dollar from 3 November 2026, that is approximately ₹28, ₹0.57 and ₹114. All rupee figures here are approximate and will move with the exchange rate and the end of the discount.

A worked example: at the listed promo rates of $0.30 per million uncached input tokens and $1.20 per million output tokens (LongCat pricing), an agent pipeline using 10 million uncached input tokens and 2 million output tokens a day comes to $3.00 plus $2.40, about $5.40 a day, roughly ₹512 at those rates (pricing page), around ₹15,400 over 30 days. That is far below the cost of keeping a multi-node cluster busy for a 3.56 TB model.

Situation Better choice
Prototype, evaluation, spiky traffic Hosted API
Existing trillion-parameter MoE serving, NPU access Self-host
Data must not leave your network Self-host, once GPU support matures
Need a legally clean base to fine-tune or redistribute Download the MIT weights

The hosted price is promotional, so rerun the numbers when it ends. Also note the model is listed on Vercel's AI Gateway, per TLDR, which gives a second route to try it.

Specific model names are where developers actually search, and they are a narrow target. We priced 694 keywords in the AI and developer-tooling space using DataForSEO volume and difficulty data. Only 72 (10.4%) cleared a winnable bar of 150-6,000 monthly searches, difficulty 20 or below, a genuine technical term, and at least three words. (n=694, measured 2026-11-09, keyword volume and difficulty data via DataForSEO). A concrete query such as "LongCat-2.5 open weights" is the kind of term that passes that bar, because it names a real artefact. If you are weighing coding-agent tooling to pair with it, our guide to open-source agent platforms for coding is a reasonable next read.

Q: Is LongCat-2.5 really open source?

A: The weights are published under the MIT licence, which is permissive. Training data and full training code are not part of the release, so "open weights" is the more accurate term.

Q: Can I use LongCat-2.5 commercially in India?

A: The MIT licence places no revenue or territory limits on commercial use. It does not grant rights to Meituan trademarks or patents, so do not use Meituan branding without permission.

Q: Can I run LongCat-2.5 on GPUs today?

A: Meituan's tested path is NPU-based through SGLang-FluentLLM. No public inference provider hosts it yet, so GPU users should wait for community adapter support.

Q: How big is the LongCat-2.5 download?

A: The repository is 3.56 TB across 208 safetensors shards of about 17.2 GB each, according to the Hugging Face page.

Q: Are the LongCat-2.5 benchmark scores reliable?

A: Treat them as indicative. Meituan labels unmarked scores as in-house measurements, and the comparison models are not the latest releases.

Q: Are smaller open models worth considering instead?

A: For narrow tasks, often yes. A specialised model such as PLaMo 3 Translate runs offline and fits on far more modest hardware, and Arete 27B shows what a mid-sized post-train can do.

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