How do I upload a build to iTunes Connect for TestFlight?

If you have a ready app,

1) Choose "generic iOS device" (don't choose any other devices connected or a simulator)

2) Go to Product --> Archive

3) If everything is fine, it should open the archive in the Organizer - there you can change the name of your upload if you wish. When ready click "validate" and then "Submit to App Store".

*) When creating the next version of the archive don't forget to change the version number from 1.0 to something different (it's "Bundle Version" somewhere in supporting files)

As the above answers are bit old and there have been some changes in iTunesConnect. You can follow these steps to upload build for beta testing :

1) Archive the project by clicking Product->Archive(make sure that the device selected is "Generic iOS Device", else the archive option will be disabled)

2) Xcode will take some time to archive the project, after successful archive a window will open (archive window).

3) There will be option "Validate" (it is always recommended to validate a build before uploading to app store). Click on the "Validate" option and if everything is alright you will see a green tick.

4) Next click on the "Submit to App Store" option, it will take some time to upload the build.

5) Once upload is complete login to your iTunesConnect account. There MyApps -> YOUR_APP_NAME.

6) There you will see a option Testflight. Inside that option you will see "iOS Builds". Check if the uploaded build is shown there, if not, don't worry it takes few minutes.

7) Now coming to the adding beta testers part. There are 2 ways ie. either you can add the testers as internal testers or external testers

a) Internal Testers

Check this link. You do not need beta review for adding internal testers.

b) External Testers

This requires beta App review. Beta app review takes less time than the actual app review. For submitting for beta app review click on the build no in Testflight->iOS Builds->build no.(something like 1.0)

Click on the "Add Testers to the build" and follow the steps. Once the app is beta reviewed, invite will be send to the testers automatically(if you choose to). You only need to submit once per build for beta review. Once a build is beta reviewed you can add upto 2000 testers.

Hope this helps.

From the Xcode menu, go to Window, then choose Organizer

From there, validate your build, then if it's good, click "Submit to app store."

After it goes through, log in to iTunes Connect and you will see your build toward the bottom of the screen