As of 2024–2025, IonCube officially supports PHP 8.1, 8.2, and 8.3 via their Loader versions 12+. However, that can reliably revert PHP 8.1 encoded files back to readable source code. The encoding process includes encryption, compression, and obfuscation that are cryptographically strong. Cracking such encoding for modern PHP versions requires breaking AES-128 or AES-256 encryption, which is not feasible without the original key.
Use php -v in the command line to check that your ionCube Loader is v13.x or higher. ioncube decoder php 81 upd
It is crucial to understand that while the official Loader is the safest and only legitimate way to run encoded files, a niche ecosystem of third-party "decoding" tools exists. These are software or services designed to bypass ionCube's security entirely, attempting to reverse the bytecode back to human-readable PHP source code. Most of these tools stopped supporting newer encoding versions, but a few projects (like the oppa26/ioncube-decode tool) claim to support up to IonCube 14/15 and PHP 8.1+ by acting as a client for commercial decoding services. As of 2024–2025, IonCube officially supports PHP 8