This is not merely a difference in file extension, like converting a .jpg to a .png; it is a difference in language and logic. It is comparable to attempting to convert a book written in Mandarin Chinese into Latin by simply changing the cover. The underlying syntax, libraries, and dependencies are completely different. Therefore, a tool that claims to "convert" an APK to an IPA online is technically incapable of rewriting the source code, restructuring the user interface for iOS standards, or re-mapping hardware calls from Android to iOS.
For users seeking cross-platform presence: apk to ipa converter online ios free
While direct conversion is impossible, you have several practical alternatives to run Android apps on your iPhone or iPad. These methods range from free to paid, and they actually work. This is not merely a difference in file