Amazon SNS vs Upstash QStash

Amazon SNS is a managed publish/subscribe service for sending messages between applications and reaching people. It can deliver notifications to application endpoints and send SMS, mobile push, and email. Standard topics support nearly unlimited messages per second with best-effort ordering and deduplication; FIFO topics preserve order and prevent duplicate delivery within five minutes, with limits of 3,000 messages per second or 10 MB per second per topic. Publishers can batch 1 to 10 messages per request, while subscribers can filter notifications. Integrations include AWS event sources and destinations such as SQS, Data Firehose, Lambda, and HTTPS. Each message can contain up to 256 KB; the Extended Client Library can store payloads up to 2 GB in S3 and publish an object reference. SNS retries delivery and supports dead-letter queues. The free tier includes 1 million requests, 100,000 HTTP notifications, and 1,000 email notifications each month. Listed paid rates include $0.50 per month for API requests, $0.06 for HTTP deliveries, and $2.00 for email deliveries; charges depend on usage.

Upstash QStash has no write-up on Specifiction yet; its figures are above.