UUID V4

128 bits, 16 bytes

122 bits of entropy, 5.31691198 × 10³⁶ possible IDs

“...the odds of collision between any two is 1 in 2.71 x 10¹⁸ Put another way, one would need to generate 1 billion v4 UUIDs per second for 85 years to have a 50% chance of a single collision.”

c4e98a74-52ea-451f-b386-ba6577419033
f53b546c-753d-42b4-a9e9-9a74d17166ac
6fcb5d03-2f77-489f-9859-28f5d60cfa3f
3ade93ff-9bc8-443f-bac3-ba4a223ab31e
958c3c38-ae90-4d8b-a55c-c1374729e9ab
d1d2b0ef-e3cb-4100-a76e-0c6f356f1939
abbfa3cb-574d-4e86-a57f-002bf7aa129f
0083a9ba-a53a-4c3f-9e2c-cc4a4210402d
1ce9c6e6-3de3-4e6f-b65d-b72c03ac55a9
03d64d48-3b43-4f6e-b517-e8b6a5669b36
    

OLC IDs

16 characters, 16 bytes (15 random characters + 1 check character)

64.829 bits of entropy (15 random characters), 3.2768 × 10¹⁹ possible IDs

Enough for about 3.8 billion unique IDs for every living person (~8.3 billion) and company (~377 million) on Earth. The average American opens between 60 and 90 unique financial accounts. For financially active individuals or those optimizing rewards and interest yields, this figure routinely exceeds 100 accounts.

About OLC IDs and the checksum

Open Location Code (OLC) alphabet Ids. OLC is a geocoding system that encodes latitude and longitude into a short string of characters. The alphabet is simplified to use only uppercase letters and digits, excluding characters that can be easily confused (like '0' and 'O', '1' and 'I').

The 16th character is a checksum: a Luhn mod 20 check character computed from the first 15. Each character is mapped to its position in the alphabet 23456789CFGHJMPQRVWX (2 = 0 through X = 19). Moving right to left, every other value is doubled, starting with the rightmost; a doubled value of 20 or more has 19 subtracted (the sum of its base-20 digits). The values are added up, and the check character is the one at position (20 − (sum mod 20)) mod 20. It catches any single mistyped character and most swaps of two adjacent characters. Hyphens are ignored.

M4J2-MMMJ-95RC-4G85
GCJ4-HP2Q-43FW-CXJH
96HC-CVFH-8CPJ-GWVP
8G99-C7Q9-3VPJ-H54C
MMMX-3M6F-FG7V-967X
QP5G-9XW9-97J8-M2CF
3MM5-VG25-WX89-JMM9
783F-6G6C-QWG6-RXXP
3479-RQ8X-J6V7-F738
72M6-9926-H37W-5HH4
    

Double UUID V4

256 bits, 32 bytes

244 bits of entropy, 2.8269553 × 10⁷³ possible IDs

f5cb78d8-9ec9-46bb-9c86-fc17c53859e5-70ba634e-c6e8-4032-ba32-f204f81df787
c003caae-6a22-476d-8805-60baf4f8c2f4-89791fc7-6229-437b-a87c-9b53a8243710
de7bbf42-9343-4d58-aefc-4c40b65802c1-2a29f0b4-0d25-488d-9089-4e749cb72336
835002cc-3fbd-4f89-9f95-de56ece7b80f-fe31e784-1c9c-4354-adc0-788423b29ae8
9c842838-d481-4ba9-a50e-7c0051ecec31-5848e347-b6b0-43f9-ac76-9d457ac404f2
bda60fdd-fe25-4f69-b615-f443553629ce-ae6a9a9f-9e0d-4ef7-bb38-2c79ce6d4877
cbcc8e5b-6051-447e-9bcd-34a747e6b5cd-9086479e-61fa-47b9-a410-40a97cf2028a
e389c8fd-dae8-4a22-9a59-55883a7c1048-af5e79ec-6d11-4c2f-a712-6cdc35d7c929
9ed066bb-3024-4525-9a8d-f9e5fb7bf81f-679d5275-5353-4ac2-8e39-ebc1cccf19b2
12d26ef8-70ea-44d2-8cd4-500a699ca810-2852c62e-8e7c-4fc8-ae5b-cdceff18993f
    

UUID V7

Unix ms timestamp (48-bit), random bits (74-bit total). Sortable by time.

Excellent DB performance (sequential inserts); sortable; no MAC leakage. Database primary keys; distributed systems. Recommended for most modern apps/DBs.

01a15926-d419-77fd-9cca-6ad39c605a68
01a15926-d41b-755a-837d-6072e7bb5d22
01a15926-d41c-73be-8248-d129f84b402a
01a15926-d41c-73be-8248-d975fa39646d
01a15926-d41c-73be-8248-e3d4ea174bb9
01a15926-d41d-778a-81ff-e8f7e3a22256
01a15926-d41d-778a-81ff-f0c440a7ca87
01a15926-d41d-778a-81ff-faaa24e78523
01a15926-d41d-778a-8200-03f0d2da7b58
01a15926-d41d-778a-8200-09313dee9761
    

Names (Short)

Randomly generated people names.

Phoebe Jacquette
Hatty Arlee
Ardith Breena
Shellie Mareah
Suzann Gretna
Carissa Giulietta
Verina Benni
Talyah Idalina
Carrie Dore
Pauli Jenilee
    

Names (Long)

Randomly generated people names.

Karol Aurelie Velma
Cristionna Aundrea Anastasia
Kaye Margaux Selle
Lettie Beverly Elane
Brandise Sybille Aurie
Stesha Jobey Robina
Sula Maia Elsa
Vivyanne Shandra Ebba
Dody Enrika Lizbeth
Daffi Betteann Victoria
    

Countries

Randomly generated country names.

Eritrea
Solomon Islands
Philippines
Senegal
Montserrat
Guyana
Guinea-Bissau
St. Helena
Anguilla
Comoros
    

Passwords

Randomly generated secure passwords.

lW1K-ZbhvXzWk5L}k$^]
@(@}>bmB3Q6-7%{N][kE
U0^]QPa^XTvT4HUCgP!f
=Xme1>#<aqg4Ksf%TIcQ
&Nm@o}fO7Cd!P)^6Li]J
(OR^aWDAnaJCq-u3<Id#
>c,e$z%hKW$msnsSO)EO
K@kH$P30!K-gM7YYrn{?
rFYZet^?4E5}=B2)FjPG
cvAuz;Wq$I(Rc&}!3L?J
    

Process Folder Names

Sequentially generated process, human-readable, folder names.

20261020-115119-Q9R4GJ
20261020-115119-XW4VQ4
20261020-115119-PFQR9C
20261020-115119-F2GJ3M
20261020-115119-GF9CVG
20261020-115119-J278GQ
20261020-115119-MQG7PQ
20261020-115119-C7Q32F
20261020-115119-M3V5CV
20261020-115119-64MH7M
    

Google-like IDs

Randomly generated Google-like 'sub' IDs.

234127122916829869565
822374570323224342925
601908943350765016076
924869110596025174416
823333020071742235251
181058176233099469271
621206140452620930769
285920999393037387104
447245752998048970477
485708438639437557918
    

Unix Timestamps

Randomly generated Unix timestamps from the past 2 months.

1788217846
1791187212
1787234402
1790091475
1788361582
1792471922
1790340407
1792187239
1789398639
1791910480
    

GUIDs

Randomly generated GUIDs using the Base64 alphabet.

x0EQQSkEU4Lh
fNCS-8XXFBN7
bldKt_vkYAc1
-WIpQQxqgTJm
DJFvHavTSMsW
lnr-COjjUEu8
c6gqWtNA8j4f
dxv9mk4L9ffS
LI8emlK9tfr2
fTJFlCs1BFYy
    

Randomly generated OLC IDs.

Secure 128-bit random IDs, using the Open Location Code (OLC) alphabet. The alphabet is simplified to use only uppercase letters and digits, excluding characters that can be easily confused (like '0' and 'O', '1' and 'I').

4J4C8XRV67WVF9R34RV8GVXP578J38
5PQ4XWFXRWHRWR9RCHQG45G4FX9HW3
WRM5QJX64F47435FGW4923G6232GC8
QPM4MM58HGJ3PXGF95HQ4XPR9MC6P8
6JH4VQ74FCWQGW54H42W63H3CH68WM
XQW25P2HHM5HH7G6QR8WGRWXGM225M
GW9JVCMH6MR8GW9V8428Q7QPV5HHQQ
GQH6JP26R8JJ3Q3MXM5JM2VHPVFVXW
3MCPGCRVM8C8QM8V87J965WPG8FWJC
2V8VWVX9G2QMV334975W3572G22F6M
    

Encrypted URL IDs (GUID)

Base64URL encoded encrypted V7 UUID tokens. Each token packs an 8-byte random IV plus a UUIDv7 XOR-masked with an HMAC-SHA256 keystream derived from the IV and a private key, so the token is opaque and non-sequential in URLs but still reversible to recover the original UUIDv7 (and its embedded timestamp) server-side.

mCCPR2I1lYT5Ko8ngTyZeY2auGvjTyty
4jlUk2TNsRF4y7LaDdh_ofrU8fq3X4iB
BXivQt4BwlPqbSd5Lxf6DybbQwuSM68v
vVNTsLCfcQww7YywZQ70FUnC92H_4tkd
Pe2og-k7KPAFaTazoZgF6Cj3yJ4o2uz4
upgHBtrcL8-3zkoQjZ9juPdiucQv3CFP
u__h9Kw_x4HpACA4NtVj1IQdU8FOBFzg
i3AbQDbNu6cr57TiGYn0OcMxg5yf6bHn
459qb99FgaEnSQtzuynLlWi0qS3_bFx7
yXS8J8A2F9lsgWLbq2f2lOJ__iHcA3Mj