Reading the results

Every tab presents tokens the same way.

The token box

The token appears in a read-only, scrollable box with its name (Custom Token, ID Token or App Check Token) and a Copy button above it. Copy puts the whole token on the clipboard. If the clipboard is unavailable, the error appears next to the button; you can still select the text in the box and copy it with Ctrl+C (⌘+C on macOS).

Decoded JWT claims

Click Decoded JWT claims to expand a table of everything in the token’s payload, sorted by name. Values are selectable for copying. Scroll the tab to reach the rest of a long table.

Timestamps are shown twice, as the raw Unix time and as UTC, for example 1791308692 (2026-10-06T17:44:52+00:00). That applies to iat (issued at), exp (expires) and auth_time (when the user signed in). Nested values, like the firebase claim in an ID token, are shown as compact JSON.

The table decodes the payload without checking the signature. It tells you what a token says, not whether a server will accept it.

Errors

When a request fails, the tab shows Error: and the message in red under its button. Problems with the top bar or the service account show in the status bar under the tabs instead, with a dismiss button. See Troubleshooting for what the messages mean.