We want to hear from mobile devs building with Unreal. What's working, what hurts?

Development Platform & Builds Mobile
1

Hey everyone,

The team working on mobile support in Unreal Engine is gathering feedback from the community, and we’d love to hear from solo devs, hobbyists, jam teams, and small studios shipping to iOS and Android.

If you’ve got even ten minutes, drop a reply below answering whichever sections are relevant to your project. Don’t feel pressured to answer everything; partial feedback is still hugely valuable. The questions below the sections are just conversation starters.

A bit about your project (optional)

Just so we can frame your answers in context:

  • Which Unreal Engine version are you on?
  • Are you modifying engine source, or running stock from the Epic Games Store / Launcher?
  • Which mobile platforms are you targeting? (iOS, Android, both)
  • What’s your lowest-spec target device on each platform?
  • Roughly where are you in development — prototype, vertical slice, soft launch, shipped?

Iterating in the Editor

  • Do you use Platform Preview when working on mobile features? If yes, is it doing what you need? If no, why not — didn’t know about it, doesn’t fit your workflow, something else?
  • What slows you down most when you’re iterating on content and code inside the Editor?

Iterating on device

  • When you want to see your game running on a real phone or tablet, how do you get it there? Launch-on from the Editor? Project Launcher? Manual builds? Something else?
  • How long does a typical iteration loop take (Editor change to seeing it on device)?
  • Have you tried Zen Server? If yes, has it helped — and has anything about it tripped you up?
  • What’s the single most painful part of on-device iteration for you?

Scalability across devices

  • Mobile devices vary wildly in performance. How are you handling that range?
  • Have you used Device Profiles and Device Profile Fragments? Did they click for you, or did you bounce off?
  • Have you ended up building your own systems for LODs, quality settings, or feature toggles because the built-in tools didn’t quite fit? Tell us about them.

UI on mobile

  • How are you tackling responsive UI across phone/tablet form factors, notches, safe areas, different aspect ratios?
  • Are you doing this mostly in UMG, Slate, or something custom?
  • What’s been the most frustrating part of mobile UI work in Unreal?

Input

  • Touch, virtual sticks, gestures, gamepad, or all of the above?
  • Are you using Touch Interface assets, Enhanced Input, custom UMG-based input handling, or something else entirely?
  • Anything you wish “just worked” out of the box for mobile input?

Shipping and updates

  • If you’ve shipped (or plan to ship) — how are you handling updates and patching on iOS / Android?

  • Anything about the build, sign, and submission pipeline that’s been a roadblock?

Third-party SDKs and services

  • Are you integrating ads, analytics, IAP, attribution, crash reporting, or other SDKs? Which providers?
  • How painful was it to wire them into an Unreal project? Did you find a plugin, write your own, or wrestle with native code?
  • If you avoided integrating something because it looked too hard, tell us about that too.

Performance

  • How are you measuring performance — in-Editor stats, on-device captures, custom logging, gut feel?
  • Are you using vendor tools (Xcode Instruments, Android Studio Profiler, Perfetto, Arm Performance Studio, Snapdragon Profiler, etc.)? Which ones have actually been useful?
  • Do you react to thermal state on mobile, or is that not on your radar yet?
  • Any automated perf testing, or is it all manual right now?

Rendering and lighting

  • Which rendering path are you using on mobile — Mobile, Deferred, Forward? Different per device tier?
  • What does your lighting setup look like — fully baked, mixed, fully dynamic?
  • Are you interested in Lumen and Nanite on high-end mobile?
  • Have you made changes to the rendering pipeline that you wish were just part of the engine?

Documentation and learning resources

  • When you need to figure something out about mobile in Unreal, where do you actually go first? Official docs, YouTube, forums, Discord servers, blog posts, source code?
  • Which topics have you found especially under-documented?

UEFN

  • Have you played around with UEFN at all? If yes, what’s your impression coming from regular Unreal?

Anything else

This is the “everything we didn’t ask about” section. Pain points, papercuts, missing features, things that confused you, things you love, things you wish someone would just fix — drop it all here. The goal is to surface the stuff that doesn’t fit neatly into a category but still matters to you every day.

Thanks for taking the time. The more honest and specific you can be (including naming the exact device, version, or workflow where something fell over) the more useful your feedback is.

:victory_hand:

2

hi @paul.georges , i tried Zen server just now, happy to see it runs normally with “quick luanch” feature now, IIRC zen server configurate as default assets server from two months age, i tried zen server with my physics android devices 3 months ago without luck, game app can’t communicate with zen server so app launched failed…

now zen server works properly and it significantly speed up my workflow for testing game assets, thanks for improving zen server for mobile.

i am on ue-5.9 and below is my zen server config:

[Zen.AutoLaunch]
DataPath="C:/UE5DerivedDataCacheZen"
LimitProcessLifetime=False                  <<-- i chagned this to false
RemoteNetworkService=GeneratedStaticKey   <<-- was 'None' before UE-5.8
LocalDataCachePathEnvOverride=UE-LocalDataCachePath
LocalDataCachePathCommandLineOverride=LocalDataCachePath
LocalDataCachePathEditorOverrideSetting=LocalDerivedDataCache
ExtraArgs=--http asio --gc-cache-duration-seconds 1209600 --gc-interval-seconds 21600 --gc-low-diskspace-threshold 2147483648 --cache-bucket-limit-overwrites --quiet --restrict-content-types --allow-external-oidctoken-exe=false
Plugins=AndroidPortForwarder

I’d love to test zen server again on Mac later, hoping it works well on iOS app also…

1 Like
3

TL;DR - Apple developer since 2008, shipped several games in the past using Apple-specific frameworks. Currently building an iOS/iPadOS/macOS game with UE 5.7.4.
The GOOD: everything works reasonably well, no major roadblocks.
The BAD: Terrible iteration times on device.

Which Unreal Engine version are you on?
5.7.4

Are you modifying engine source, or running stock from the Epic Games Store / Launcher?
Stock from Epic Launcher

Which mobile platforms are you targeting? (iOS, Android, both)
iOS/iPadOS only.

What’s your lowest-spec target device on each platform?
All Apple devices that support iOS 18 or later.

Roughly where are you in development — prototype, vertical slice, soft launch, shipped?
Vertical slice. Approaching beta.

Do you use Platform Preview when working on mobile features? If yes, is it doing what you need? If no, why not — didn’t know about it, doesn’t fit your workflow, something else?
No, because the only way to properly test touch input, usability, actual performance and thermal behavior is on the real device.

What slows you down most when you’re iterating on content and code inside the Editor?
The need to close the editor and re-launch every time I make changes to the CPP code, although I completely understand the underlying reasons. Live Coding is not an option since it broke things for me in the past and caused major headaches. Not using it ever again :slight_smile:

Iterating on device

When you want to see your game running on a real phone or tablet, how do you get it there? Launch-on from the Editor? Project Launcher? Manual builds? Something else?
Package the project in UE → Launch Xcode project → Test

How long does a typical iteration loop take (Editor change to seeing it on device)?
A few minutes. Actually, it’s way faster to make changes directly in C++ through Rider/Xcode and just test directly on device, without even opening the Editor. Of course, it only works in very specific cases.

Have you tried Zen Server? If yes, has it helped — and has anything about it tripped you up?
Yes, and it has helped significantly. Overall iteration times were vastly reduced.

What’s the single most painful part of on-device iteration for you?
The iteration times on device are painful.

Scalability across devices

Mobile devices vary wildly in performance. How are you handling that range?
Have you used Device Profiles and Device Profile Fragments? Did they click for you, or did you bounce off?
I use Device Profiles, and so far they seem to work pretty well for my needs. Although the Device Profiles list in the Editor is a bit… chaotic? disorganized? :wink:

UI on mobile

How are you tackling responsive UI across phone/tablet form factors, notches, safe areas, different aspect ratios?
I have a very minimal UI by design, just to avoid these issues.

Are you doing this mostly in UMG, Slate, or something custom?
UMG + custom CPP code.

What’s been the most frustrating part of mobile UI work in Unreal?
Testing on device.

Input

Touch, virtual sticks, gestures, gamepad, or all of the above?
Touch + gestures.

Are you using Touch Interface assets, Enhanced Input, custom UMG-based input handling, or something else entirely?
Enhanced Input + some custom input handling.

Anything you wish “just worked” out of the box for mobile input?
Touch and gesture handling could be improved, or at least make it more dev-friendly. Better documentation on the matter could also help.

Shipping and updates

If you’ve shipped (or plan to ship) — how are you handling updates and patching on iOS / Android?
I just re-submit the whole game to the App Store. It’s not very large in size, so no big deal.

Anything about the build, sign, and submission pipeline that’s been a roadblock?
No problems so far, as long as I set up everything properly both in UE and in Xcode.

Third-party SDKs and services

Are you integrating ads, analytics, IAP, attribution, crash reporting, or other SDKs? Which providers?
Apple-specific frameworks. (CloudKit, GameKit, StoreKit2, etc.). No Ads.

How painful was it to wire them into an Unreal project? Did you find a plugin, write your own, or wrestle with native code?
I write my own plugins/bridging code in Objective-C++ for stuff like the CloudKit savegame syncing or Apple’s GameCenter integration. Not easy, but perfectly doable after some research.

Performance

How are you measuring performance — in-Editor stats, on-device captures, custom logging, gut feel?
Are you using vendor tools (Xcode Instruments, Android Studio Profiler, Perfetto, Arm Performance Studio, Snapdragon Profiler, etc.)? Which ones have actually been useful?
In-Editor stats are great. I also use the good old custom logging, and Instruments when I really need to dig down.

Do you react to thermal state on mobile, or is that not on your radar yet?
Yes.

Any automated perf testing, or is it all manual right now?
Manual.

Rendering and lighting

Which rendering path are you using on mobile — Mobile, Deferred, Forward? Different per device tier?
Mobile Deferred for all iOS/iPadOS devices, since it seems to work pretty well with TBDR chips (Apple Silicon specifically).

What does your lighting setup look like — fully baked, mixed, fully dynamic?
Fully dynamic. No baking.

Are you interested in Lumen and Nanite on high-end mobile?
I don’t really need Lumen/Nanite on mobile for my current project but it could be interesting to test these features on high-end mobile in the future. Not a priority for me, though.

Have you made changes to the rendering pipeline that you wish were just part of the engine?
Nope.

Documentation and learning resources

When you need to figure something out about mobile in Unreal, where do you actually go first?
Official docs - Useful, though mostly focused on Android.
YouTube - Not useful since 99% of the content there is aimed at beginners/hobbyists.
Forums - Not that good. It might take a long time to get a useful answer, if ever.
Discord - Good if you can find the right servers/channels. Otherwise, same as YouTube.
Blog posts - Extremely useful if you are lucky enough to find the right one.
Source code - Absolutely. Thank God whe have access to the source code :wink:

Which topics have you found especially under-documented?
Anything related to iOS --or the Unreal<->Apple workflow in general, including Mac- is well under-documented on EPIC’s side. Almost all documentation that covers Mobile is specifically aimed at Android. Same for Unreal Fest sessions: most of them are very interesting but they mostly cover Android. This needs to be improved if you really want more Apple developers to use Unreal. Right now, roughly 90% of my colleagues, both indies and also those working in studios, use ‘the other’ engine for iOS game development, and don’t plan to move anytime soon.

UEFN

Have you played around with UEFN at all? If yes, what’s your impression coming from regular Unreal?
Not interested in UEFN.

1 Like
4

UEFN Fortnite on Samsung Galaxy is HUGELY better than UE5.*,

When you finish a game for PC that looks like FN, M*Blocks.

Could go on forever, but just stick to getting MAJOR Cooks to work first time in UEFN.

Dont bother to think you can debug of mobile UE5.*, but you can in UEFN

Maybe because the basis of Fortnite Creative was originally on console, then mobile that it works.

Some Indie Dev have tried to go from UEFN to UE5.* and the battle scars are to deep to return.

When a game crashes you are left as a broken dev in UE 5.*.

With UEFN step through your code with Visual Studio Code and UEFN connected to the mobile phone until you find the problem

Devs are under so much pressure and this is because big brands want there app on mobile fast The fastest way the build Nike Shoes add was on UEFN, they even put their assets of older shoes in Fortnite Shop. Specially built in UEFN for the Nike mobile market build time 4 months in UEFN.

Other devs were trying to use same assets in UE5.* and they gave lead time of 6 to 9 months! and they said this was normal for the industry!

In UEFN simply select Launch → Connect Mobile, have you mobile running Fortnite, make a cup of tea, and you are ready to test you island

in UE5.* well look at all the configuring needed to connect as some sort of server, then wait 20 minutes for the app to cook on your PC unless you have some 12 core process costing thousands.

As and Indie Dev since UE 4.19 to 5.8 simply would not use for mobile, even if you paid me!!.

With Wi-Fi 6 streaming to mobile is the way to go go and that how UEFN get round the problems.

Dont get me started on the lack of documentation of UE 5.* mobile.

@paul.georges

Update NEW UEFN documentation section on Mobile

Mobile Development in Fortnite | Fortnite Documentation | Epic Developer Community

Read this even if you are thinking of using UE5.*

IMHO build the app as a Fortnite island, make and debug in UEFN then export to UE5.*

Good luck Exporting to UE5.* and building as an App, because you are goanna need it! :rofl: :grinning_cat: :scream:

If there is a forum post for documentation , always go to UEFN/Fortnite documentation because its much easier and clearer to understand only point to UE5.* documentation if really have to!

1 Like
5

What do you mean gathering feedbacks? Do you even read this forum? The entire thing is bugged and crashes most android devices atm. This should already be your immidiate priority along with estimated hotfix patch date.

Don’t get me started on iOS bugs too. Basically, the whole UE mobile platform is very unstable with lots of forced updates that add lots of complexity and redundant workload.