URN Code 40 Encoder/Decoder

A web-based tool for encoding and decoding text using the URN Code 40 specification, including extended encoding support.

Features

• Encode and decode text using the URN Code 40 specification
• Support for extended encoding:
  • FB: Long numeric strings (9-24 digits)
  • FC: ISO/IEC 646 characters
  • FD: Double-byte UTF-8 characters
  • FE: Triple-byte UTF-8 characters
• Copy encoded or decoded text to clipboard
• Persistent storage of entered text using localStorage

URN Code 40 Specification

URN Code 40 is an encoding scheme that provides a method to encode data in conformity with the urn:oid namespace scheme. The basic encoding process takes a string of three data characters and compacts these into two bytes (four hexadecimal characters).

Basic Character Set

• Space, A-Z, hyphen (-), period (.), colon (:), digits 0-9

Encoding Formula

The standard encoding uses the formula:

(1600*C1) + (40*C2) + C3 + 1

Where C1, C2, and C3 are the decimal values of three characters from the URN Code 40 character set.

Extended Encoding

URN Code 40 also includes extended encoding capabilities:

• FB: Long numeric string encoding (for 9-24 digits)
• FC: ISO/IEC 646 characters not in the base table
• FD: Double-byte UTF-8 characters
• FE: Triple-byte UTF-8 characters

URN Code 40 Character Set

Graphic Symbol	Name	HEX Code	8-bit code	URN Code 40 (decimal)
	PAD			0
A	Capital letter A	41	01000001	1
B	Capital letter B	42	01000010	2
C	Capital letter C	43	01000011	3
D	Capital letter D	44	01000100	4
E	Capital letter E	45	01000101	5
F	Capital letter F	46	01000110	6
G	Capital letter G	47	01000111	7
H	Capital letter H	48	01001000	8
I	Capital letter I	49	01001001	9
J	Capital letter J	4A	01001010	10
K	Capital letter K	4B	01001011	11
L	Capital letter L	4C	01001100	12
M	Capital letter M	4D	01001101	13
N	Capital letter N	4E	01001110	14
O	Capital letter O	4F	01001111	15
P	Capital letter P	50	01010000	16
Q	Capital letter Q	51	01010001	17
R	Capital letter R	52	01010010	18
S	Capital letter S	53	01010011	19
T	Capital letter T	54	01010100	20
U	Capital letter U	55	01010101	21
V	Capital letter V	56	01010110	22
W	Capital letter W	57	01010111	23
X	Capital letter X	58	01011000	24
Y	Capital letter Y	59	01011001	25
Z	Capital letter Z	5A	01011011	26
-	Hypen-Minus	2D	00101101	27
.	Full stop	2E	00101110	28
:	Colon	3A	00101110	29
0	Digit zero	30	00110000	30
1	Digit one	31	00110001	31
2	Digit two	32	00110010	32
3	Digit three	33	00110011	33
4	Digit four	34	00110100	34
5	Digit five	35	00110101	35
6	Digit six	36	00110110	36
7	Digit seven	37	00110111	37
8	Digit eight	38	00111000	38
9	Digit nine	39	00111001	39

Development

This project is built with:

• SvelteKit
• TypeScript
• Pico CSS