Zapier, Power Automate or custom: choosing a workflow tool

Zapier is a hosted connector service. You pick a trigger in one app and an action in another, and the flow runs in their cloud, usually within a minute of the event. Setup takes an afternoon. It is the quickest way to test whether an idea is worth automating at all, since a working prototype costs an afternoon and nothing else.

Power Automate is Microsoft’s equivalent, tied closely to Outlook, SharePoint, Teams and Excel on OneDrive, with desktop flows that click through older Windows programs when no connector exists.

A custom build is code written for your process and hosted where you choose. It costs more to start. In return, you own the rules, the data and every screen.

Check the connector list against your real stack before anything else. Gmail, Google Sheets, Slack and Shopify are covered everywhere, but a desktop accounting package such as Tally, a local ERP or a transport portal often is not. Test the exact action you need. A connector that lists your accounting app may support only a handful of triggers, and creating a sales voucher is rarely one of them.

WhatsApp needs care. Sending template messages requires the official business API through a provider, each tool handles that differently, and receiving and parsing replies is rarer still.

Where no connector exists you fall back on file drops, email parsing or screen automation, each of which is slower and easier to break than a direct link. These work until a screen changes.

Simple approvals are easy everywhere. A manager gets an email and clicks approve. The trouble starts with rules such as sign-off by amount, a substitute approver on leave and escalation after two days. Write the real rule down first. Without it, you cannot tell which tool can express it.

Power Automate handles multi-stage approvals reasonably well inside Microsoft. Zapier needs workarounds or an added approvals app. Code can follow the matrix exactly.

Ask where the history lives. Who approved, when, from which device, and can an auditor export it? A debugging log is not an audit record.

Hosted tools usually charge by task or run. A flow that handles ten orders a day is cheap. The same flow across five branches and several steps multiplies quickly, so model your busiest month, not your average one.

Maintenance is the quiet cost. Someone must repair the flow when an app renames a field or a token expires. Then the flows become a black box.

Custom code has its own upkeep. It sits in version control with documentation, and you choose who looks after it. The knowledge stays in writing, not in one person’s head. If you expect heavy volume, ask for a quote on a one-time build and compare it with three years of task fees.

Choose Zapier when the job is a light link between common cloud apps and failure is only an annoyance. Choose Power Automate when staff live in Outlook and SharePoint and IT already manages the Microsoft licences.

Choose custom when money, stock or compliance records pass through the flow. Say so plainly. The same applies when connectors are missing or per-task costs would outgrow a one-time build. Keep a file of the decisions you made, so the next person knows why Zapier runs the lead alerts while code runs the invoicing.

List your five most important workflows and score each tool on the four points above. Trial the cheapest option on the least risky one. Review the choice after six months of real use.