How do I know if a profile is development, ad hoc, enterprise or App Store?

From what it contains: an enterprise profile works on all devices (ProvisionsAllDevices); development and ad hoc profiles list devices, and only development allows a debugger (get-task-allow); an App Store profile lists no devices. The page says which it is and why.

What happens when a provisioning profile expires?

Apps signed with a development, ad hoc or enterprise profile stop opening on devices once it expires, and they must be signed again with a new profile. Apps downloaded from the App Store are not affected: Apple signs those itself.

How can I list the UDIDs in a profile?

Open the profile above: every UDID is listed and numbered, and "Copy all UDIDs" puts them on the clipboard, one per line.

Is it safe to share a provisioning profile?

It holds no private key, so nobody can sign apps with it alone, but it does name your team, your app and your testers' device IDs. Treat it as internal rather than secret. This page does not upload it anywhere.

Is the signature checked?

Yes, against the certificate inside the file: a profile changed after signing is reported. Whether that certificate really is Apple's is not checked against Apple's certificate authority, so the page shows the signer's name as the file states it.

Is my profile uploaded?

No. The file is read by this browser tab on your own device, and nothing is sent anywhere.

Stays on your computer How this works

Free mobileprovision viewer: read an iOS provisioning profile

Open a .mobileprovision or .provisionprofile to see the app ID and team it is for, whether it is a development, ad hoc, enterprise or App Store profile, when it expires, its entitlements, the device UDIDs it lists and the signing certificates it allows. The file is opened in your browser and is not uploaded.

Drop a .mobileprovision file here, or click to choose oneIt is opened by your browser, on this computer. Nothing is uploaded.

About the provisioning profile viewer

A provisioning profile is the permission slip Apple issues with every iPhone, iPad, Apple TV, Watch and Vision Pro app a developer signs: which app (bundle ID), from which team, signed with which certificates, on which devices, with which capabilities, until which date. Xcode keeps them in the background, every .ipa carries one as embedded.mobileprovision, and when an app will not install or a build fails to sign, the profile is the first thing to read. It is a property list wrapped in Apple's signature, so opening it in a text editor shows mostly noise.

This page unwraps the signature, reads the property list and lays it out: the profile's kind worked out from what it contains, the days left before it expires, each entitlement in plain words, every device and every certificate with its fingerprints. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What you can see

The profile's name, app ID and bundle ID (wildcards marked), team name and team ID, and UUID
Its kind: development, ad hoc, enterprise (in-house) or App Store, and for Mac profiles Developer ID, with the reason the page gives
Creation and expiry dates, with an "expired" or "expires in N days" notice
Every entitlement (push notifications, app groups, associated domains, iCloud, keychain groups...) with what it allows, and the whole list as written, ready to copy
The device UDIDs it lists, numbered, with a button to copy them all
Each developer certificate it allows: name, team, validity, serial number, SHA-1 and SHA-256 fingerprints
Who signed the profile, and whether it has been changed since; the property list itself can be saved as a .plist

How to check a profile

Drop the .mobileprovision file on the box above, or click the box and choose it. For an app, the profile is inside the .ipa at Payload/<App>.app/embedded.mobileprovision; the IPA viewer reads it too.
Check the expiry date first: an expired profile is the most common reason an ad hoc or enterprise app stops opening.
For a test build that will not install, look for the tester's UDID in the device list.
When signing fails with "no signing certificate", compare the certificates' SHA-1 fingerprints with the ones in Keychain Access.

Reading a profile on a Mac or Windows without this page

Mac: in Terminal, security cms -D -i profile.mobileprovision prints the property list; add -o profile.plist to save it. Profiles Xcode downloaded are in ~/Library/Developer/Xcode/UserData/Provisioning Profiles (older Xcode: ~/Library/MobileDevice/Provisioning Profiles). With Xcode installed, Quick Look (space bar) in Finder also shows a summary.
Windows and Linux:openssl smime -inform der -verify -noverify -in profile.mobileprovision prints the property list without checking Apple's signature. OpenSSL comes with Git for Windows.
iPhone and iPad: installed profiles for enterprise apps are under Settings > General > VPN & Device Management. A .mobileprovision file can be opened on this page in Safari.

Questions

How do I know if a profile is development, ad hoc, enterprise or App Store?: From what it contains: an enterprise profile works on all devices (ProvisionsAllDevices); development and ad hoc profiles list devices, and only development allows a debugger (get-task-allow); an App Store profile lists no devices. The page says which it is and why.
What happens when a provisioning profile expires?: Apps signed with a development, ad hoc or enterprise profile stop opening on devices once it expires, and they must be signed again with a new profile. Apps downloaded from the App Store are not affected: Apple signs those itself.
How can I list the UDIDs in a profile?: Open the profile above: every UDID is listed and numbered, and "Copy all UDIDs" puts them on the clipboard, one per line.
Is it safe to share a provisioning profile?: It holds no private key, so nobody can sign apps with it alone, but it does name your team, your app and your testers' device IDs. Treat it as internal rather than secret. This page does not upload it anywhere.
Is the signature checked?: Yes, against the certificate inside the file: a profile changed after signing is reported. Whether that certificate really is Apple's is not checked against Apple's certificate authority, so the page shows the signer's name as the file states it.
Is my profile uploaded?: No. The file is read by this browser tab on your own device, and nothing is sent anywhere.