Analysis: when Lambda Web Functions beats classic Lambda on cost

AWS launched Lambda Web Functions on October 12, 2026: it runs a normal HTTP server, handles up to 128 requests per environment and bills active CPU instead of wall-clock time. Memory is charged for as long as the environment exists, so 1 GB costs about $9.50 a month before a single request.

• Memory costs $0.0000036667 per GB-second for the environment's lifetime
• Active CPU costs $0.0000276944 per vCPU-second, about double classic
• Break-even against a 1 GB classic function is 2.33M requests/month
• Against a 512 MB classic function it never pays off