G2 Vendor Directory

Knock vs. Customer.io

Side-by-side across both vendors’ full G2 portfolios — reviews, ratings and category coverage aggregated to the company, not a single product.

Knock

New York, NY

Customer.io

Portland, OR

MetricKnockCustomer.io
Avg. rating4.64.4
Total reviews149990
Review growth (QoQ)-75.0%+7.1%
Products on G211
Categories covered57
Best category rank#2 in Notification Infrastructure#1 in Transactional Email
Small Business75.9%59.3%
Mid-Market22.0%37.4%
Enterprise2.1%3.2%