The original title is "EC2 Spot vs On-Demand: the true cost difference in 2026"

Short summary

EC2 Spot instances advertise discounts up to 90%, but real-world savings average 40-60% after accounting for interruption overhead and retry costs. The 2026 production pattern combines 60-70% Spot diversified across instance families, 20-30% On-Demand with Compute Savings Plan, and 5-10% pure On-Demand for bursts, achieving 45-55% blended discount. Diversify across 5-15 instance types and availability zones to cut interruption rates from 5% to under 1% per instance-hour.

• •Actual Spot savings (40-60%) lag headline discounts (90%) due to 5-15% interruption rates and engineering overhead
• •Diversifying across 5-15 instance families and AZs reduces interruptions from ~5% to under 1% per instance-hour
• •Hybrid pattern: 60-70% Spot + 20-30% On-Demand (with Compute Savings Plan) + 5-10% burst On-Demand yields 45-55% blended savings safely

Generated with AI, which can make mistakes.