Best LLM APIs for Office Work

Pick a brain for your AI COO: it reads documents, understands PDFs and images, reasons carefully and stays affordable. 5 providers in China + 5 overseas — every link goes straight to official signup.

How to use it: pick a provider → click Sign up to grab an API key from their site → open the AiCOO Desktop app → paste the key into the ② AI Engine field at login, and your AI COO can really hold a conversation, read your files and help you draft plans. Without a key, the Desktop app runs in mock demo mode.

🇨🇳 Recommended in China (sign up with just a phone number)

Provider · Model	Best for office work	Vision	Reasoning	Price guide	Sign up
DeepSeek deepseek-chat / reasoner	Careful reasoning, strong Chinese writing, widely seen as the best value — sign up and go	MediumText-focused	High	about ¥1 in / ¥4 out (per million tokens)	Sign up →
Zhipu GLM GLM-4.6 / GLM-4.6V	The most mature Chinese office agent; native multimodal — reads images, text and PDFs	StrongNative	High	mid-range, pay as you go (list price)	Sign up →
Qwen Qwen3.7-Max / qwen-vl	Full Alibaba ecosystem and a long model ladder — from flagship to budget — rock solid for office work	StrongNative	High	Max about ¥12 in / ¥36 out lighter tiers cost less	Sign up →
Doubao · Volcano Ark Doubao-Seed-2.1	Natural Chinese, strong multimodal and very stable — more than enough for office work, and cheap	StrongNative	Medium-high	Pro about ¥6 in / ¥30 out	Sign up →
Kimi (Moonshot) Kimi K3	The best at very long documents — contracts, research reports, long PDFs	MediumLong-doc focus	High	flagship about $3/$15 (≈ ¥21/¥105)	Sign up →

China note: all five providers above accept a Chinese mobile number at signup. Once you verify — on the web or through Alipay — you can start calling the API. Most expose OpenAI-compatible endpoints, so you can connect straight from the Desktop app.

🌍 Recommended overseas (needs an overseas network / payment method)

Provider · Model	Best for office work	Vision	Reasoning	Price guide	Sign up
Google Gemini Gemini 3 Pro / Flash	Native multimodal and the strongest at long PDFs — our top value pick for office work	StrongNative	High	Pro about $2/$12 Flash about $0.75/$3.75	Sign up →
Anthropic Claude Opus / Sonnet 4.x	The best reputation for document writing and plan reasoning — rigorous and rarely makes things up	StrongSupported	High	Sonnet about $3/$15 Opus costs more	Sign up →
OpenAI GPT GPT-5.2	Well-rounded across the board, with the most mature ecosystem and tooling	StrongSupported	High	about $1.5 / $10	Sign up →
xAI Grok Grok 4	Cutting-edge performance, better value than OpenAI, strong at deep analysis	StrongSupported	High	about $3 / $15	Sign up →
Mistral Mistral Large 3	European open-model value, privacy-friendly, with good-enough vision	MediumSupported	Medium-high	about $2 / $6	Sign up →

Overseas note: Google, OpenAI and Anthropic are not open to mainland China, so you need an overseas network connection plus an international credit card. If you don't have those, just use the five China providers above — the experience is every bit as complete.

💡 Which one to pick

In China, low hassle, best value → DeepSeek (careful reasoning + strong Chinese + great price)
Native PDF and image understanding for Chinese office work → Zhipu GLM-4.6V or Qwen-VL
Very long contracts and research reports → Kimi K3
Overseas, strongest PDF parsing → Google Gemini 3 Flash (better value)
Overseas, top-tier writing and rigor → Claude Sonnet

Why recommend office models instead of coding models?
AiCOO is an AI-driven office Desktop app, where you and your AI collaborate in real time on a local AI Workbench. The models are tuned for business office scenarios: rigorous reasoning, PDF and image understanding, and a cost profile that suits heavy daily use.

Office work does not need extreme coding ability — leave code to professional developers. Your AI COO (AiCOO) focuses on delivering plans, documents, business analysis and the evidence behind decisions, and you can switch engines in the Desktop app whenever you like.