HardGuard25

Generate human-friendly unique IDs using a 25-character alphabet designed to eliminate visual confusion.

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Possible combinations
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Bits of entropy
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Generated this session

Codes will appear here

Why these 25 characters?

Standard alphanumeric codes use 36 characters (0-9, A-Z). That creates problems when humans read, transcribe, or dictate codes aloud. HardGuard25 keeps all 10 digits and 15 carefully chosen letters, removing 11 sources of confusion. When a letter and a digit compete for the same visual slot, the digit always wins.

0 1 2 3 4 5 6 7 8 9 A C D F G H J K M N P R U W Y
RemovedReason
OLooks like 0 (zero)
ILooks like 1 (one) or l (lowercase L)
LLooks like 1 (one) or I (uppercase i)
BLooks like 8; dyslexia mirror pair with D
SLooks like 5
ZLooks like 2
ELooks like 3 for dyslexic readers; digits take priority
QLooks like O in some typefaces; dyslexia mirror pair with P
VEasily confused with U
TResembles a plus sign in some contexts
XCollides with multiplication operator; varies by locale

Read the full specification on GitHub.

HardGuard25 by Sam Rogers · Snap Synapse
Original article · GitHub · Specification

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