Twenty years of administering Microsoft 365 tends to produce the same handful of questions, over and over: is this tenant name taken, what does this license GUID actually correspond to, is this feature available on our plan. Each one has a definite answer, but getting it usually means opening an admin center, launching PowerShell, or digging through Microsoft's documentation. This page collects a growing set of free, browser-based tools built to answer those questions in seconds.
| Tool | What it does |
|---|---|
| Microsoft 365 Tenant Name Check | Checks whether a yourname.onmicrosoft.com tenant name is available or already claimed. |
| M365 License SKU Lookup | Decodes Microsoft 365 license SKUs, GUIDs, and service plans into friendly names, and back again. |
Microsoft 365 Tenant Name Check
Every Microsoft 365 tenant is assigned a permanent, globally unique yourname.onmicrosoft.com address, and that name can only exist once across the entire Microsoft 365 ecosystem. This tool checks a proposed tenant name against Microsoft's public sign-in metadata and reports, in about a second, whether the name is still available or already in use.
It is useful when provisioning a new Microsoft 365 or Office 365 tenant, planning a tenant rename, or confirming whether an organization already has an Entra ID tenant registered under a given name.
M365 License SKU Lookup
Microsoft identifies the same license three different ways: a friendly name in the admin center, such as Microsoft 365 E5, a string ID in PowerShell and Graph output, such as SPE_E5, and a GUID. Outside the admin center, matching those identifiers to a plain English product name is not always simple.
This tool translates between friendly names, string IDs, and GUIDs for both license SKUs and the individual service plans inside them, covering Microsoft's full published licensing reference. It also supports bulk lookups, useful for translating exports, scripts, or tenant audit reports in one pass.
Why these tools exist
Most Microsoft 365 questions can be answered from documentation. Some can only be answered by checking directly, and the official paths to that answer often require signing in, opening an admin center, or writing a PowerShell script. These tools exist for the moments when a direct answer is all that is needed.
Each one runs entirely in the browser against publicly available data. No tenant is accessed and no input is stored. This list will grow as more of these internal utilities are cleaned up for public use.