New stores: 14 days of Protector freeFirst 25 stores.Uptime, daily scans, Slack and Telegram alerts. No card.See what’s included

Every monitoring tool watches something. Start by working out what.

Uptime monitors watch whether a URL responds. Audit tools grade a crawl on one date. Store monitors read the store's own data — orders, prices, stock. The three sound alike in a listing and catch entirely different failures, so these pages set out what each one sees, including the rows where the other tool is the better buy.

Cassian™ is a store monitor. It is not the cheapest way to check whether a URL responds, and it does no keyword research. Where a specialist is the right answer, these pages say so.

Not sure which category you need?

The seven questions that separate them — and when a cheap uptime monitor is genuinely the right answer.