Better Xcode Build Numbers

24 May 2018

iOS and macOS apps have a version number and a build number. Typically you see these in Xcode or iTunes Connect represented something like this:

1.0 (1)

This is version number 1.0, build number 1

As I’m sure you know, the build number is used to differentiate different builds of the same version, so you might upload build 1, then make amendments, and then upload build 2

I used to manually increment this build number each time I created a build, but that strategy has it’s problems:

• iTunes Connect will reject builds that have the same build number as a previously uploaded build. So you can waste a load of time if you forget to increment the build number.
• Sometimes I couldn’t remember if I’d incremented it, so would end up doing it twice
• The build number says nothing useful about this particular build

The last point is the most important. How do you know that you have the right build? QA might tell you that they found a problem on build 8… which one was that again? Or you’re submitting your app on iTunes Connect, and the build is 9 - was that the one you just created or not?

Recently I’ve been using a timestamp (yyyyMM.dd.HHmm) for my build numbers, which looks like this:

1.0 (201805.15.1407)

This build was created on 15/05/2018 at 14:07

Note that you can only have three periods in the build number, which is why I’ve put the year and month together

This has some great benefits:

• If QA want to test the changes that were built today, they can easily verify that the build time of their version looks right
• Newer builds always have higher build numbers, and it’s automated, so you don’t have to worry that a developer made a mistake
• If you upload a build to iTunes Connect and then another the next day with some changes, it’s obvious which is which one is which!

This is pretty easy to achieve using a ‘Run Script Phase’ in Xcode’s build phases with the following script:

# Generate the build number using current date and time
buildNumber=$(date "+%Y%m.%d.%H%M")

# Set the build number in plist file
/usr/libexec/PlistBuddy -c "Set :CFBundleVersion $buildNumber" "${TARGET_BUILD_DIR}/${INFOPLIST_PATH}"

I'm Steve Barnegren, an iOS developer based in London. If you want to get in touch:

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