TestFlight or an OTA install link?

Three questions decide it. Do you have a signed build? If not, neither route works yet — both need a paid Apple Developer Program membership. Are the testers' devices already in your provisioning profile? If not, TestFlight is easier, because it needs no UDIDs. Do they need the build in the next few minutes? If yes and the devices are provisioned, an OTA link is faster. Everything else is detail.

No, and this is the most common misconception. Internal testers — up to 100 App Store Connect users on your own team — get builds with no Beta App Review at all, usually within minutes of processing. Review applies to external testers, and then only to the first build you send to them; later builds generally go out without a full review. If your testers are colleagues, TestFlight is not the slow option and the case for anything else is weaker than it looks.

When the device is already in your provisioning profile and the person needs the build now — a client demo this afternoon, a QA hand-off mid-sprint, a per-branch build a reviewer wants to try. It is also better when the tester will not or cannot install TestFlight: they need the TestFlight app and an Apple Account, and a client who just wants to see your work often has neither. And it is the only option for Android, which TestFlight does not support at all.

The device has to be registered. Apple allows 100 devices per product family per membership year, the count does not go up if you disable a device mid-year, and it only resets when your membership renews. If a tester's iPhone is not in the profile the install fails, and the only fixes are to collect their UDID and rebuild, or to use TestFlight. That ceiling is the single strongest argument for TestFlight at any real scale.

For TestFlight, yes — they install the TestFlight app and accept the invitation with an Apple Account, and Managed Apple Accounts from reserved domains cannot be used to test builds. For an OTA install link, no: they open the link in Safari and install. That difference decides more real cases than any feature comparison, because it is the difference between sending someone a link and asking them to set up an account first.

Most teams that ship seriously do. The common split is an OTA link for the daily build and for anyone outside the beta programme, and TestFlight for the release candidate and the wider external group — because the release candidate is the build you want rehearsed against App Review anyway. They are not mutually exclusive and nothing about using one prevents the other.

Use TestFlight. Ad hoc cannot reach them — the 100-device registration limit is Apple's and there is no way around it — while TestFlight allows up to 10,000 external testers with no UDID collection at all. Anyone telling you otherwise is selling you something.

On BetaDrop a link lives 3 days by default and the file is deleted when it expires rather than archived; paid plans extend that to a year or ten. A TestFlight build expires 90 days after upload. Neither is permanent, which matters if you were planning to treat either as the place a build lives.