Free LLM Tier or Self-Hosted? Three Numbers Decide, Not the Price Tag

Description and use

By measuring token burn, latency, and data sensitivity, the team avoided free tier throttling and ensured reliable LLM deployment.

Problem

Teams often choose free managed LLM tiers or self-hosted solutions based on marketing claims or data privacy fears, without measuring actual workload fit, leading to cost overruns or performance issues.

Outcome

Using the three-number framework, the team avoided costly free tier rate limits and ensured latency and data privacy requirements were met, leading to a cost-effective and reliable LLM deployment.

Workflow

• Run a 3–5 day burn probe to capture token usage and burst factor.
• Calculate daily burn and burst factor from probe data.
• Determine realistic latency budget by measuring p95 response times under load.
• Classify data sensitivity based on presence of PII, financial, or regulated health data.
• Apply decision table to choose free tier, paid API, or self-hosted deployment.
• If in middle range, extend probe to a full week for stability.
• Adjust thresholds based on team operational tolerance.
• Implement chosen deployment and monitor metrics.

Evidence

Run this for three to five days inside your existing LLM client wrapper. It records every request's token usage, computes a daily burn, and — more importantly — calculates a burst factor, which is the ratio of your busiest hour to your average hour.

Source

Ask your users, not your infrastructure: what response time makes the feature feel broken? For an interactive chat widget, p95 under two seconds is usually fine; for an agent that sits inside a request path, you might need p95 under 300 milliseconds.

Source

Be brutally honest here: if a prompt contains customer PII, internal financials, or regulated health data, the free tier conversation is already over.

Source