Max UUID Generator

Generate and copy the standardized all-one max UUID for upper bounds, sentinels, and range tests.

Max UUID
Copy the standardized all-one UUID in the representation your system expects.
Always returns the same value
Canonical UUID
ffffffff-ffff-ffff-ffff-ffffffffffff
32-digit hex
ffffffffffffffffffffffffffffffff
UUID URN
urn:uuid:ffffffff-ffff-ffff-ffff-ffffffffffff
Reference
The max UUID is a fixed sentinel value, not a random identifier.
Bits
128 bits set to one
Version
Special form
Variant
All bits set
Regeneration
Always returns the same value

What Is a Max UUID?

A max UUID is the standardized UUID whose 128 bits are all set to one. Its canonical text form is ffffffff-ffff-ffff-ffff-ffffffffffff, and it is often used to mean the highest possible UUID value.

When to Use It

Use a max UUID when an API, database query, fixture, or range check needs a UUID-shaped upper bound or sentinel value. It is useful in tests, migration scripts, pagination cursors, and protocols that define an explicit maximum UUID value.

What to Watch For

Do not treat the max UUID as a generated unique identifier. It is the same value every time, so storing it where a real object ID is expected can hide sentinel logic, break uniqueness assumptions, or make records sort to the end unexpectedly.