TestFlight explained: what it is and when you need it

By Sigsten Gustavii· 26 October 2026· 8 min read

Sooner or later, everyone who makes an iPhone app hears "send me a TestFlight link". TestFlight is how most iPhone apps are tried by real people before they reach the App Store, and Apple runs it for free as part of its developer membership.

This guide explains what TestFlight is, the two kinds of testers, the limits Apple sets, how a build gets there, and when you can skip it. All the numbers come from Apple's own TestFlight documentation, as of October 2026.

What TestFlight is

TestFlight has two halves. On the developer side, it is a tab in App Store Connect where builds you upload can be shared with testers. On the tester side, it is a free app called TestFlight, from the App Store, that installs those builds on an iPhone or iPad and keeps them up to date.

A TestFlight build is the real app, signed by Apple, the same build that can later go to the App Store. That is what makes it valuable: testers try exactly what you are about to release, on their own phones.

Internal and external testers

TestFlight has two kinds of testers, with different rules.

Internal testing is for the people who work on the app. It needs no review, so builds are ready as soon as Apple has processed them. External testing is for everyone else. Before external testers can install a build, it goes through Beta App Review, a lighter check than the full App Review. Apple notes that later builds of the same version may not need another full review.

The limits to know

• 90 days. A TestFlight build can be tested for up to 90 days after it is uploaded. After that it expires and testers need a newer one.
• A developer membership. TestFlight is part of Apple's Developer Program, $99 a year. A free Apple ID cannot use it.
• An App Store Connect record. The app needs its record in App Store Connect, and the build has to be uploaded there.
• Test information. For external testing, Apple asks what testers should test, plus a feedback email and a short description.

How a build gets into TestFlight

The traditional route goes through Xcode on a Mac: archive the app, sign it, upload it to App Store Connect, wait for Apple to process it, then add testers. With Borel, the upload happens from your browser.

Step 1: Get the app ready

Make the app and test it in the iPhone simulator in your browser. Fix what is obviously broken; testers' time is better spent on what you cannot see yourself.

Step 2: Join the Apple Developer Program

Enrol at developer.apple.com for $99 a year. It covers TestFlight and the App Store for every app on your account.

Step 3: Send the build to Apple

In Borel, Publish is on the Pro plan, from $20 a month. It walks you through the app's listing, connects your App Store Connect account, then builds the app with Xcode on Borel's Mac, signs it and uploads it. Once Apple has processed the build, it shows up in TestFlight. You never open Xcode.

Step 4: Add testers in App Store Connect

Open your app in App Store Connect and go to the TestFlight tab. Add yourself and your team as internal testers, or create an external group, invite people by email or turn on a public link, and fill in the test information. External groups wait for Beta App Review.

Step 5: Testers install the TestFlight app

Each tester installs TestFlight from the App Store, accepts the invitation or opens the link, and installs your app. New builds appear there automatically.

Step 6: Read the feedback, fix, repeat

Collect what testers report, ask for the fixes in the Borel chat, and send a new build. When testers are happy, submit the build for App Review from App Store Connect.

Here is a short note you can send testers so their feedback is useful:

Thanks for testing [app name]!
Please try:
1. [The main thing, e.g. create an account and add three items]
2. [Something new in this build]
3. Anything you would normally do in an app like this
When something feels wrong, take a screenshot in TestFlight and say what you tapped and what you expected.
This build expires in 90 days; you'll get newer ones automatically.

What testers see

It helps to know what the experience is like on the other side, so your instructions make sense to testers:

1. They get an email invitation or open your public link on their iPhone or iPad.
2. They install the free TestFlight app from the App Store, if they do not have it yet.
3. TestFlight shows your app with the test information you wrote: what to test and a short description.
4. They tap Install, and your app appears on the home screen like any other app.
5. When you upload a newer build, TestFlight offers it to them, and can update it automatically.
6. From inside the app or TestFlight, they can send feedback with a screenshot and a comment.

Groups and public links

External testers are organized in groups in App Store Connect. A group gets the builds you choose, so you can give a small group of trusted testers every build and a larger group only the stable ones. Each group can also have a public link: anyone who opens it can join, up to a limit you set, without you typing in their email address.

Public links are convenient for a newsletter or a community, and easy to share too widely. Set a tester limit, and turn the link off when you have enough people. You can remove testers at any time.

TestFlight compared with an App Store release

When you do not need TestFlight

TestFlight is for testing with other people. If the app is only for you, or you are still early, there are quicker ways:

For your own phone, Borel Companion installs the app on Pro with a free Apple ID and renews it while Companion runs. For quick checks, the simulator is fastest. Our post on installing your own app without the App Store review compares every route.

When TestFlight earns its place

TestFlight is most useful at three moments in an app's life:

• Before the App Store. A week with a handful of testers catches the confusing screen or the broken edge case before a reviewer or a stranger does.
• Before a big update. Send the new version to your testers while the current one stays on the App Store, and release it once they are happy.
• For a standing beta group. Keen people who like trying new things early can stay in a group and get builds as you make them.

Between those moments, the simulator and your own phone are faster. TestFlight adds an upload and, for external testers, a review, so it pays off when other people's eyes are the point.

Common TestFlight mistakes

• Inviting everyone on day one. Start with internal testers, fix the obvious issues, then open it up.
• Leaving test information empty. External testing needs it, and testers need to know what to look at.
• Forgetting the 90 days. A tester who opens an expired build sees nothing. Upload a newer build before it lapses.
• Treating Beta App Review as App Review. Passing one does not guarantee the other; the full review checks more.
• Testing only on the newest iPhone. Ask a tester with an older or smaller phone to join.

TestFlight and the App Store

TestFlight sits between your last change and the App Store. Once a build passes your testers, you submit that same build for review. For the full route from browser to App Store, read how to publish an app to the App Store without a Mac, and for the review itself, why apps get rejected and how to avoid it.

I would send every build to a few friends on TestFlight before review. Their questions are the cheapest bug report you will ever get.

– Sigsten

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