Three things worth knowing before you tap "place order"
In the US, 15-20% of the order subtotal, or a flat $3-5 for a short, simple delivery, covers most situations.
On several major delivery apps, drivers see the tip amount before deciding whether to accept a delivery. An order showing $0 tip can genuinely sit unclaimed longer, or be assigned to a less experienced driver, than one with a tip already attached — this has been widely reported and is not simply a rumour.
Bad weather, long distances, multiple stops, or a large and heavy order are all reasonable, common reasons to tip above the usual range.
Example: a $35 dinner order
15% = $5.25 · 20% = $7.00.
In heavy rain, or for a delivery that took the driver well out of their normal area, many customers add an extra $2-3 on top of that calculation.
Outside the US
Tipping delivery drivers is far less embedded as a system in most other countries. In the UK and much of Europe, rounding up or a small cash tip at the door is appreciated but not expected the way it is in the US. In much of Asia and Latin America, delivery fees are usually considered to already cover the driver, though a small extra amount for a difficult delivery is still a kind gesture.
Should you tip before or after delivery? Pre-tipping through the app, as described above, can affect whether and how quickly your order is accepted. Adding a cash tip at the door afterwards is always a safe, additional option regardless of what you already selected in the app.