Both protect Python code, but in fundamentally different ways. SOURCEdefender encrypts your source and decrypts it back at runtime. PyLocket never ships your key, never rebuilds your source, and adds the licensing and delivery you need to actually sell your app.
It encrypts your .py files into an AES-256 .pye format, then decrypts them back to your original source in memory at import time. Because decryption happens on the user's machine, the ability to decrypt travels with your app, and public decryptors for the .pye format exist. It's an encryption utility; licensing, delivery, and updates are left to you.
It encrypts each function's bytecode individually. Keys are issued to each licensed device at activation and never embedded in your app; at runtime the native runtime decrypts one function at a time and hands the bytecode to CPython to run. There's no static file-plus-key to run a decryptor against, so no one-click decryptor exists. And it's a full platform: licensing, device binding, revocation, delivery pages, trials, updates, and checkout are built in.
An honest comparison, including where SOURCEdefender is the better fit.
| Capability | SOURCEdefender | PyLocket |
|---|---|---|
| Decryption key never ships with the app | ✘ | ✔ |
| Original source cannot be recovered | ✘ | ✔ |
| Per-function encryption in a native runtime | ✘ | ✔ |
| Built-in licensing, device binding, revocation | ✘ | ✔ |
| Sell, deliver, and push updates | ✘ | ✔ |
| Identity-verified developers | ✘ | ✔ |
| No percentage of your sales | ✔ | ✔ |
| Supports Python 3.7 to 3.11 | ✔ | ✘ |
| Free distribution of free apps at any volume | ✔ | ✘ |
SOURCEdefender is priced per developer seat (roughly £15/mo to £1,500/yr). PyLocket is a flat subscription per account plus $4 per license activated, with no percentage of your sales. Based on publicly available information; verify current specifics with each vendor.
Both are legitimate tools built by people who care about protecting Python code. The right choice depends on whether you need an encryption utility or a full protection-and-licensing platform.