Firefox issues with sideloaded iOS apps?

[cheyanne4578]

I’ve recently been testing a few sideloaded iOS apps using iOS sideloading tool, and I've noticed something strange when using Firefox on iOS. Some app-linked webviews or browser-based functions like OAuth logins and embedded media aren’t rendering properly — they either break or behave inconsistently compared to Safari.

This seems to happen mostly when the app relies on in-app browsers or redirects through Firefox. Safari works fine in the same scenario, so I'm wondering if Firefox is more restricted when interacting with sideloaded apps or if it's an iOS-level issue.

Has anyone else run into this? Could it be due to WebKit limitations, or does Firefox just handle certain embedded contexts differently?

Appreciate any insights or similar experiences!

[evelyngrace]

I’ve actually noticed similar quirks when testing sideloaded apps that use external web-based components on iOS.

From what I understand, all iOS browsers — including Firefox and Chrome — are still required to use Apple’s WebKit engine under the hood, so in theory, rendering should be pretty consistent across the board. But in practice, Firefox on iOS sometimes does behave differently, especially when it comes to embedded views and redirect handling.

I’ve run into issues with OAuth flows not completing properly when a sideloaded app opens them via Firefox instead of Safari. It seems like Firefox doesn’t always handle certain cookies or session storage correctly in those contexts — especially when jumping between in-app browsers and external tabs. My guess is that it's partly due to how tightly Apple locks down app-to-app communication and how limited browser extensions or advanced networking are on iOS.

One workaround that helped me: try forcing the app to open links in Safari rather than relying on Firefox’s in-app webview. You can sometimes tweak that using settings in the sideloading tool (AltStore, Scarlet, etc.) or by modifying the app’s Info.plist before signing.

If you're exploring sideloading tools, the Scarlet iOS App Store is definitely worth a look. It provides a smoother UI and better support for advanced features compared to some alternatives. You can learn more at scarletapps.com.

[danielmartinhq]

Yeah, I’ve seen this happen too, and it’s honestly one of those weird quirks of iOS. Even though Firefox looks like a separate browser, it still has to use Apple’s WebKit engine under the hood — so it’s never a true “independent” browser like on Android or desktop. That’s why sideloaded apps that rely on custom webviews or embedded browsers sometimes act up when routing things through Firefox.

In my case, I was testing a sideloaded Reddit client and a couple of media apps. OAuth and login redirects through Firefox either didn’t complete or just froze mid-load. Once I switched everything to open via Safari or the system browser, everything worked fine.

From what I’ve read, it’s not necessarily a Firefox issue but rather how iOS limits interaction between third-party browsers and sideloaded apps. Apple keeps those APIs pretty locked down.

If you’re testing regularly, I’d suggest using Safari for anything that involves login flows or web-based embeds. Firefox on iOS still struggles in those areas because of the sandboxing and limited communication with other apps.