🧭LLM Buying Guide: Decide by Scenario, Budget and Compliance
Facing 20+ mainstream models, how do you pick the right one? Converge fast along three dimensions: scenario, budget, compliance.
The biggest mistake in model selection is wanting everything. The right approach: constrain first, then pick the best within the feasible set. Three dimensions converge fast.
Dimension 1: Scenario Sets the Capability Floor
Pin down the primary scenario: support chat, code generation, long-document analysis or multimodal? Capability requirements differ wildly — lock the 'capability floor' first.
- Support / content: Chinese ability + cost first
- Code / Agent: reasoning stability + long context
- Document analysis: context window + retrieval augmentation
Dimension 2: Budget Sets the Price Band
Estimate monthly token usage and multiply by unit price for the true cost. The capability gap between flagship and value models on common tasks is usually smaller than the price gap.
The first principle of selection: real tasks completed per unit cost — not a few extra benchmark points.
Dimension 3: Compliance Sets the Deployment Form
Whether data may cross borders and whether private deployment is mandatory decide cloud API vs. open-source self-hosting. Finance, healthcare and government usually require open-source private deployment.
Practical tip: filter by the three dimensions with this guide's filters, then run the savings calculator to work out cost — you'll have a shortlist in 10 minutes.