GoKawiilAWS Lambda Web Functions bill memory for minutes after requests finish, Easel finds
Easel tested AWS's newly announced Lambda Web Functions and found that execution environments kept running and accruing memory charges for 5 to 7 minutes after handling their last request, with no configurable idle timeout available. The company measured idle periods of 313 to 411 seconds across six environments, and found memory accounted for about 88% of total compute and request costs in its tests. Easel ultimately decided to run its own compute infrastructure instead, reporting it was also faster.
GoKawiil's interpretation of the reporting above, not reported fact.
The findings suggest that while Web Functions market active-CPU-only billing as a cost advantage, memory charges during idle periods could erode or even dominate those savings for bursty or low-traffic workloads, according to Easel's measurements. Because AWS documents the idle behavior but offers no way to shorten it, teams evaluating the service may need to model real-world idle time rather than relying on advertised per-request pricing. Easel's decision to build its own infrastructure hints that other companies with similar traffic patterns might reach the same conclusion.
- Lambda Web Functions kept billing memory for 5–7 minutes after the last request in Easel's tests.
- Memory charges made up roughly 88% of total compute and request costs in the experiment, despite low actual usage.
- Easel abandoned Web Functions and returned to running its own infrastructure, citing both cost and speed.
Source: easel.sh, 2026-11-12
Published there as: “AWS Lambda Web Functions keep billing memory ~7 minutes after the last request”
Read the original report → The summary and analysis above are GoKawiil's own, written from reporting by the source above. Facts and quotes belong to the original publisher.