Skip to content
, ,

LongCat-2.5 Open Weights: Meituan’s 1.6T MIT Model, Benchmarks, API Price and Hardware

8–11 minutes
Woman in a server room holding a tablet showing a LONGCAT card, hook 1.6T model now free under MIT

Meituan, the Chinese food-delivery giant, has released the weights of LongCat-2.5 under the MIT licence. It is a 1.6-trillion-parameter mixture-of-experts model with about 48B active parameters, and it reads images and video as well as text.

The weights landed on Hugging Face on 9 November 2026, a week after Meituan introduced the model. On Meituan’s own tables it trades blows with Claude Opus 5 and DeepSeek V4.1 Flash on agent and coding tests.

This guide covers the specs, every headline benchmark, the API price, how to call it (including from Claude Code), what it really takes to self-host, and the licence fine print.

TL;DR

  • What: Meituan LongCat-2.5, native multimodal MoE for long-horizon agent work. 1.6T total / ~48B active. Weights at meituan-longcat/LongCat-2.5, MIT licence.
  • Benchmarks (vendor-reported): Terminal Bench v2.1 88.4 (Opus 5: 89.1), BrowseComp 91.9, DeepSWE v1.1 64.6 (DeepSeek V4.1 Flash: 74.2).
  • API price (limited-time): $0.30 input / $1.20 output per million tokens, cached input $0.006. OpenAI- and Anthropic-compatible endpoints.
  • Self-hosting: server-class only. BF16 weights are roughly 3.2 TB; Meituan’s only deployment guide targets Chinese NPUs via SGLang-FluentLLM. No GGUF or official vLLM recipe yet.
  • Best for: visual coding (turn screenshots into apps), browsing agents and cheap long agent runs through the API.

What LongCat-2.5 Is

LongCat is Meituan’s model family. LongCat-2.0 arrived on 30 June 2026, and the multimodal LongCat-Next research came before this release. LongCat-2.5 merges both ideas into one model.

Its trick is how it sees. Native-resolution images are turned into discrete visual tokens that sit in the same space as text, so the model reasons over a screenshot the way it reasons over code.

  • Built for: long agent tasks: browsing, multi-step coding, working through a whole codebase.
  • Visual coding: inspect a screenshot or video and build or fix the matching app.
  • Hybrid thinking: switch reasoning on for hard tasks, off for cheaper, faster replies.
  • Trained on Chinese chips: Meituan says training ran entirely on domestic accelerators.

Specs at a Glance

Spec LongCat-2.5
Developer Meituan LongCat team
Weights released 9 Nov 2026 (model unveiled ~2 Nov)
Architecture Native multimodal mixture-of-experts
Total parameters 1.6T per the model card (Hugging Face metadata shows 1.8T)
Active per token ~48B
Input Text, images, video (video by URL on the API)
Output Text
Context Not stated as one number; evals ran at 256K to 1M tokens
Weights format Safetensors, BF16 and F32 tensors
Serving quantisation W4A4 experts + KV8 (Meituan reports +92% decode throughput vs W8A8KV16)
Licence MIT

Note: the 1.6T vs 1.8T gap is unexplained. The extra may be the vision components or F32 tensors. Size your hardware from the actual file total, not the headline.

Benchmarks vs Opus 5, GPT-5.6 Sol and DeepSeek

All numbers below come from Meituan’s model card. LongCat’s own scores are in-house and vendor-reported; rival scores marked by Meituan come from public reports. No independent evaluation had been published when I checked.

Benchmark LongCat-2.5 LongCat-2.0 Claude Opus 5 GPT-5.6 Sol DeepSeek V4.1 Flash Kimi K3
Terminal Bench v2.1 88.4 70.8 89.1 88.8 90.6 88.3
Terminal Bench v4.0 38.5 3.0 53.9 37.3 31.2 12.6
DeepSWE v1.1 64.6 9.7 68.8 72.7 74.2 67.5
SWE Atlas Codebase QnA 58.3 33.1 63.2 46.0 55.2 54.3
BrowseComp 91.9 79.9 90.8 90.4 91.5 91.2
HLE (with tools) 63.1 37.5 64.7 58.0 63.9 56.0
MCP Atlas 83.1 61.8 85.8 81.8 84.4 84.2
AutomationBench 51.8 15.8 50.3 45.8 54.8 46.7
Vision2Web 78.6 – 80.2 73.5 79.2 79.0
3DCodeBench (text to 3D) 55.4 – 54.3 52.3 53.3 49.3
VideoMME 85.2 – – 89.5 – 90.0

How to read these numbers

  • Huge jump over 2.0: DeepSWE went from 9.7 to 64.6, and Terminal Bench v4.0 from 3.0 to 38.5.
  • Frontier-adjacent, not frontier: on the hardest test (Terminal Bench v4.0) it trails Opus 5 by 15 points. Newer models do better still: the tbench.ai leaderboard lists Claude Opus 5.5 at 64.8 and GPT-6.1 Sol at 58.2 with their own agent harnesses.
  • Where it leads: BrowseComp and 3DCodeBench, which fit the browsing-agent and visual-coding pitch.

API Pricing and What a Run Costs

Meituan’s API is the practical way to use LongCat-2.5. Prices below are Meituan’s limited-time discounted rates, and the page warns they can change.

Model Input / 1M Output / 1M 200K in + 100K out
LongCat-2.5 $0.30 (cached $0.006) $1.20 $0.18
DeepSeek V4.1 Flash (off-peak) $0.15 $0.60 $0.09
GPT-6.1 Sol $2 $10 $1.40
Claude Opus 5.5 $4 $20 $2.80
Claude Fable 5.2 $8 $40 $5.60

Rival prices are list prices as reported by VentureBeat on 9 November. For the full picture, see our AI API pricing comparison.

Tip: the $0.006 cached input rate is 50x cheaper than uncached. Agents that resend a long system prompt and file context every turn benefit the most.

How to Use the LongCat-2.5 API

LongCat speaks both the OpenAI and Anthropic API formats, so existing SDK code works with a new base URL.

Setting Value
OpenAI-compatible base URL https://api.longcat.chat/openai
Anthropic-compatible base URL https://api.longcat.chat/anthropic
Model ID LongCat-2.5
Auth Authorization: Bearer YOUR_API_KEY
  1. Get a key. Sign up on the LongCat API platform at longcat.ai and create an API key.
  2. Install the SDK. Run pip install openai.
  3. Send a request. Use the code below; set enable_thinking to False for cheaper replies.
  4. Add images. Pass an image_url block with a public URL or a base64 data URL. Videos must be public URLs.
from openai import OpenAI

client = OpenAI(api_key="YOUR_API_KEY",
                base_url="https://api.longcat.chat/openai")

resp = client.chat.completions.create(
    model="LongCat-2.5",
    messages=[{"role": "user", "content": [
        {"type": "text", "text": "Rebuild this page as HTML and CSS."},
        {"type": "image_url", "image_url": {"url": "https://example.com/screenshot.png"}},
    ]}],
    temperature=1.0, top_p=0.95,
    extra_body={"chat_template_kwargs": {"enable_thinking": True}},
)
print(resp.choices[0].message.content)

Meituan’s recommended sampling is temperature 1.0, top_p 0.95 with thinking on. Function calling uses the standard OpenAI tools format.

Image and video limits

  • Image formats: PNG, JPG, JPEG, WebP, GIF. No SVG or HEIC.
  • Image size: up to 10 MB, 5,120 px per side, 5,242,880 total pixels, 100 images per request.
  • Video: URL only, up to 100 MB, under one hour, 10 videos per request.

Use LongCat-2.5 in Claude Code

Because there is an Anthropic-compatible endpoint, you can point Claude Code at LongCat-2.5 with environment variables. This is the standard Claude Code custom-endpoint setup.

export ANTHROPIC_BASE_URL="https://api.longcat.chat/anthropic"
export ANTHROPIC_AUTH_TOKEN="YOUR_LONGCAT_KEY"
export ANTHROPIC_MODEL="LongCat-2.5"
claude

On Windows PowerShell use $env:ANTHROPIC_BASE_URL="..." for each line. For switching between several providers, our Claude Code Router guide shows a cleaner setup.

Warning: your code and prompts go to Meituan’s servers in China. Check your company’s data rules before sending private repositories.

Can You Run It Locally? Hardware Reality

Short answer: not on a PC. Only ~48B parameters fire per token, but all 1.6T must sit in memory.

Precision Weights size (my estimate) Realistic hardware
BF16 (as published) ~3.2 TB Multi-node GPU cluster
8-bit ~1.6 TB Two 8-GPU H200/B200 nodes
4-bit (W4A4 like Meituan’s serving) ~0.8-0.9 TB One 8x B200 or 8x H200 node, plus KV cache room
~1-2 bit GGUF (does not exist yet) ~350-550 GB 512 GB-1 TB RAM server, if llama.cpp ever adds support

These are estimates from parameter count (2 bytes per BF16 parameter), scaled from Kimi K3’s published GGUF sizes. They exclude KV cache, which grows with long contexts.

  • Official route: Meituan’s SGLang-FluentLLM branch longcat-2.5-npu, written for Chinese NPUs.
  • vLLM / SGLang mainline: no official recipe at release. The repo uses custom code, so expect to wait for upstream support.
  • llama.cpp / Ollama / LM Studio: no support or GGUF yet.

Note: even 2x RTX 5080 with 128 GB RAM (160 GB total) is several times short. If you want a big open model at home, see running DeepSeek V4.1 Flash locally or our VRAM guide.

LongCat-2.5 vs Other Open-Weight Giants

Model Size (total / active) Licence Vision Runs on a big PC?
LongCat-2.5 1.6T / ~48B MIT Images + video No
DeepSeek V4.1 Flash-1017 552B + 196B Engram / 8-16B MIT Images 1-bit on ~128-145 GB RAM+VRAM
Kimi K3 / K3.1 Pro 2.8T / 104B (K3.1 Pro) Open weights Images (+ video via API) No (~610 GB minimum)
Mistral Large 4 1T / 52B Open weights See our Mistral Large 4 post No

Sources: model cards and our Kimi K3 VRAM guide and DeepSeek V4.1 Flash guide.

Which should you pick?

  • Cheapest strong coder via API: DeepSeek V4.1 Flash still wins on price and DeepSWE.
  • Screenshot-to-app and browsing agents: LongCat-2.5 is worth testing; it leads BrowseComp and 3DCodeBench in Meituan’s table.
  • Hardest terminal tasks: closed models like Claude Opus 5.5 remain clearly ahead.
  • Running at home: neither LongCat nor Kimi; pick DeepSeek V4.1 Flash at 1-bit or a smaller model.

Licence, Limits and Unknowns

  • MIT licence: commercial use, modification, fine-tuning and redistribution are allowed if you keep the notice.
  • No trademark or patent grant: the card says the licence does not give rights to Meituan trademarks or patents.
  • Your responsibility: Meituan says the model is not fully evaluated for every use and asks developers to check accuracy, safety and fairness for high-risk settings.
  • Unknowns: API context window, max output, rate limits and how long the discounted price lasts.
  • Data location: the hosted API is run by Meituan; self-hosting is the only way to keep data in-house.

Troubleshooting

Problem Likely cause Fix
Image rejected SVG/HEIC, over 10 MB or over 5,120 px Convert to PNG/JPG/WebP and resize
Video upload fails Base64 video sent Host the video at a public URL; video is URL-only
Image ignored or request fails Media sent inside a plain text string Use content blocks: [{type:"text"}, {type:"image_url"}]
Replies slow and token-heavy Thinking mode on Set enable_thinking to False for simple tasks
Lost reasoning across turns History reasoning dropped Pass save_history_reasoning_content=True in chat_template_kwargs
vLLM or llama.cpp won’t load it No upstream support yet Use the API or the SGLang-FluentLLM NPU branch

My Take

LongCat-2.5 is the most interesting kind of open release: not the best model, but a near-frontier model under MIT with genuine visual reasoning. That combination is rare.

The jump from 2.0 is dramatic, and Meituan training it on domestic chips is a story in itself. But all scores are self-reported, and the hardest benchmarks still show a clear gap to Claude and GPT.

For most readers, the API is the real product. At $0.18 for a 300K-token run, it’s cheap enough to test as a visual-coding agent today. Wait for independent benchmarks before betting a production pipeline on it.

FAQ

Is LongCat-2.5 really open source?

The weights are released under the MIT licence, which allows commercial use and modification. Training data and full training code are not released.

How many parameters does LongCat-2.5 have?

About 1.6 trillion in total with roughly 48 billion active per token, per the model card. Hugging Face metadata shows 1.8T.

Can I run LongCat-2.5 on my gaming PC?

No. Even a 4-bit copy needs around 0.8-0.9 TB of memory by my estimate, and there is no GGUF or llama.cpp support yet.

How much does the LongCat-2.5 API cost?

$0.30 per million input tokens, $0.006 cached, and $1.20 per million output tokens, as a limited-time price.

Is LongCat-2.5 better than Claude Opus 5?

Not overall. Meituan’s own numbers show it close on Terminal Bench v2.1 and ahead on BrowseComp, but 15 points behind on Terminal Bench v4.0.

Can LongCat-2.5 understand video?

Yes. It scored 85.2 on VideoMME (vendor-reported), and the API accepts video by public URL, up to 100 MB and under an hour.

Can I use it with Claude Code?

Yes, through the Anthropic-compatible endpoint by setting ANTHROPIC_BASE_URL to https://api.longcat.chat/anthropic and your LongCat key.

Sources

Free weekly email

Get new AI guides every week

One short weekly email with our newest local AI, ComfyUI and AI tool guides. No spam, no pop-ups, just the good stuff.

Free. Unsubscribe anytime in one click. We only use your email to send this newsletter. See our privacy policy.

Woman in a server room holding a tablet showing a LONGCAT card, hook 1.6T model now free under MIT