How to cut your AI bill without making prompts worse
Five practical ways to reduce tokens while keeping the instructions that matter.
Updated Jul 11, 2026 · Reviewed by PromptCostLab
Token and pricing information changes frequently. Use this guide for planning and verify model-specific limits and prices with the provider before production billing.
Measure before cutting
Start with the exact request assembled by your application. Developers often optimize the visible user prompt while repeated system instructions, retrieved documents, or conversation history create most of the bill. Record input tokens, output tokens, calls per task, cache usage, and retry rate.
Remove repetition, not requirements
Delete duplicated background and examples that teach the same rule. Convert long prose into concise constraints, but keep acceptance criteria, safety rules, and required output fields. The goal is not the shortest prompt; it is the smallest prompt that produces reliable results.
Retrieve less, retrieve better
RAG systems frequently overspend by sending too many chunks. Improve metadata filters, rerank results, deduplicate overlapping passages, and set a relevance threshold. Fewer high-quality passages can improve grounding while reducing context use.
Route work by difficulty
Use a fast model for predictable extraction, tagging, classification, and formatting. Escalate ambiguous or high-value cases to a stronger model. Add a quality check or human approval where a cheap first pass could create business risk.
- Fast route for routine work.
- Balanced route for most conversations and RAG.
- Flagship route for complex reasoning.
- Fallback route for provider or quality failures.
Control output and caching
Set an output limit that matches the task, request structured concise answers, and stop generating when the required fields are complete. Keep stable prompt prefixes consistent when provider caching is available. Finally, measure cost per completed business task so optimizations that increase retries do not appear cheaper than they are.
Prices, token behavior, and model limits change. These primary provider docs are the right place to verify the details before shipping.