IFTTT
Free plan forever with unlimited Applet runs
Limits: 2 Applets, standard speeds
Free Automation tools
FeaturedYour tool here: Sponsor this spot, $19/mo (first month free)
Make
Free plan with the visual scenario builder
Limits: 1,000 credits/month, 1 data store (1 MB)
n8n
Free self-hosted Community Edition (on GitHub)
Limits: Cloud plans are paid (from €20/mo); some features are Cloud or Enterprise only
Pipedream
Free plan with every feature for building and testing, 3,000+ connectors
Limits: Development only; production use needs a paid plan
Zapier
Free plan with two-step Zaps
Limits: 100 tasks/month