Free MAS Tools

A small set of free, no-signup tools built on top of the Microsoft Activation Scripts knowledge base. Everything runs locally in your browser — nothing is uploaded.

Activation Error Decoder

Paste any 0x… Windows or Office activation error and get an instant explanation, root cause and MAS fix.

KMS Client Setup Keys Lookup

Browse the full list of Generic Volume License Keys (GVLKs) for every Windows and Office edition. One-click copy.

Activation Status Checker

Step-by-step slmgr & ospp commands to verify whether your Windows or Office install is genuinely activated.

Windows Edition Converter

Pick your current and target edition (Home → Pro, Pro → Enterprise, Enterprise → LTSC) for the exact MAS path.