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License Activation Guide

This guide explains how to activate and manage your pyobfus Professional Edition license.

Prerequisites

  • Python 3.9 or higher
  • pyobfus installed: pip install --upgrade pyobfus (0.5.26 or later recommended; see Troubleshooting if you are on an older version)
  • Your license key (PYOB-XXXX-XXXX-XXXX-XXXX), sent by email right after purchase

Important: The license key email comes from license@arong.eu.org and may land in your Spam/Junk folder. Check there if it has not arrived within a few minutes of purchase.

Try Before You Buy

Not sure Pro is right for you? Try it free for 5 days. No credit card is required and the email is optional:

pyobfus-trial start                        # or: pyobfus-trial start --email you@example.com
pyobfus input.py -o output.py --string-encryption --anti-debug
pyobfus-trial status

Quick Activation

# 1. Install or upgrade pyobfus
pip install --upgrade pyobfus

# 2. Register your license (verifies it online and registers this machine)
pyobfus-license register PYOB-XXXX-XXXX-XXXX-XXXX

# 3. Check it
pyobfus-license status

A successful registration prints ✓ License verified successfully!. After that, Pro features are available, for example:

pyobfus input.py -o output.py --level pro
pyobfus input.py -o output.py --string-encryption --anti-debug --control-flow

Run pyobfus --help for the full list of Pro options (string encryption, control-flow flattening, dead-code injection, anti-debugging, runtime string vault, expiry and device binding, and more).

Managing Your License

Check status

pyobfus-license status            # local information: key, type, expiry, last verification, this device
pyobfus-license status --verify   # also re-check the license online
pyobfus-license status --json     # machine-readable output

Devices

Each license can be active on up to 3 devices at a time. Registering a fourth device does not fail: the device you have not used for the longest time is released automatically to make room.

Move to another machine

  1. On the old machine, release its device slot (needs internet):

bash pyobfus-license deactivate

This frees the slot on the license server and removes the local license from that machine.

  1. On the new machine:

bash pip install --upgrade pyobfus pyobfus-license register PYOB-XXXX-XXXX-XXXX-XXXX

If the old machine is gone or no longer works, skip step 1. Once you register more than 3 devices, the least recently used one is released automatically.

pyobfus-license remove only deletes the license stored on this machine. It does not free the device slot on the server. Use deactivate when you want the slot back.

Offline Use

After a successful online verification the license is stored locally (~/.pyobfus/license.json, or %USERPROFILE%\.pyobfus\license.json on Windows) and pyobfus does not need to contact the server again for 3 days.

After that, pyobfus tries to re-verify online. If the server cannot be reached, Pro keeps working from the stored license. It stops only if the server actively reports that the license has been revoked or has expired.

Troubleshooting

"License verification failed ... Access denied" or "request blocked"

Versions of pyobfus before 0.5.26 cannot reach the license server: a network filter in front of the server rejects their requests, which older versions report as Access denied. Your key is fine.

  • Recommended: upgrade, then register again:

bash pip install --upgrade pyobfus pyobfus-license register PYOB-XXXX-XXXX-XXXX-XXXX

  • If you cannot upgrade right now, register without the online check:

bash pyobfus-license register PYOB-XXXX-XXXX-XXXX-XXXX --no-verify

This unlocks Pro on this machine immediately and keeps working, but the machine is not recorded on the server.

"License not found" or "Invalid license key"

  1. Copy and paste the key from the purchase email instead of typing it.
  2. Make sure the key starts with PYOB-.
  3. If the key is definitely correct, contact support (below).

"Could not reach the license server"

Check your internet connection or proxy and try again later. With an already stored license, Pro keeps working in the meantime (see Offline Use). With deactivate, nothing is changed locally, so you can simply retry.

"License is revoked" or "License has expired"

The server reports that this license is no longer valid. Contact support with your license key.

Support

For license or billing questions (lost key, invoice, activation problems), email zhurong0525@gmail.com with the subject "License Activation Issue" and include:

  • your license key, or the email address used for purchase
  • the exact error message
  • pyobfus --version, python --version, and your operating system

For bugs and feature requests, please use GitHub Issues.

FAQ

How many devices can I use?

Up to 3 devices at a time. Use pyobfus-license deactivate to release one yourself; otherwise the least recently used device is released when you register a fourth.

Do I need internet to use Pro features?

Only to register a machine and, occasionally, to re-verify. If the server cannot be reached, Pro keeps working from the stored license.

Is the license lifetime?

Yes. The license does not expire, and future Pro updates are included at no extra cost.

What if I lose my license key?

Email support from the address you used for the purchase (or include it, plus the approximate purchase date). We will resend the key to that address.

Can I share my license?

No. Each license is for the purchaser's own use. See the Terms of Service.

Last Updated: 2026-10-05