Linear barcodes

1. Check overall appearance and any text under barcode. In particular look for elongated bars at the centre and ends of the symbol (characteristic of EAN/JAN/UPC barcodes)

2. Look closely at your barcode and estimate the number of different thickness bars present. In many cases this is 2, although it may be 3 or 4. Compare the number with the values in the table.

3. look at the first few and last few bars of your barcode and compare them with the patterns listed below, where
W=wide bar, N=narrow bar, w=wide space, n=narrow space

For further information on any barcode type click on the image below.

Codabar	Number of widths 3, but 2 is common Start often WnN but 8 possible choices! Stop often NnW but 8 possible coices	Digits plus $ ; . + / Start/stop may be A B C D E N T *
Code 11	Number of widths 3 Start NnWwN Stop NnWwN	Digits and -
Code 39	Number of widths 2 Start NwNnWnWnN Stop NwNnWnWnN	Digits and upper case letters and space - . $ % + /
Code 93	Number of widths 3 Start  NnNnW(4) Stop NnWnN(4)	Digits and upper case letters and space - . $ % + / ( )
Code B	Number of widths 2 Start  NnNnNnW Stop NnNnNnNnN	Digits only
Code 128	Number of widths 4 Start  W(2)nN Stop W(2)n(3)W(3)nNnW(2)	Any. GS1-128 are similar, but readable text generally contains brackets.
EAN14	Number of widths 4 Start  W(2)nNn(2)W(3) Stop W(2)n(3)W(3)nNnW(2)	Digits only with (01) or (02) prefix
EAN-13	Number of widths 3 Start NnN Stop NnN	13 Digits only JAN is similar
UPC-A	Number of widths 3 Start NnN Stop NnN	12 Digits only
EAN-8	Number of widths 3 Start NnN Stop NnN	8 Digits only
UPC-E	Number of widths 3 Start NnN Stop NnNnN	7 Digits only (plus a leading 0)
Standard 2 of 5	Number of widths 2 Start  WnWnN Stop WnNnW	Digits only
IATA 2 of 5	Number of widths 2 Start  NnN Stop WnN	Digits only
Interleaved 2 of 5	Number of widths 2 Start  NnN Stop WnN	Digits only
ITF-14	Number of widths 2 Start  NnN Stop WnN	14 Digits only
ITF-6	Number of widths 2 Start  NnN Stop WnN	6 Digits only
Matrix 2 of 5	Number of widths 2 Start  W(5)nNnN Stop W(5)nNnN	Digits only
MSI	Number of widths 2 Start Wn Stop NwN	Digits and upper case A to F
Plessey	Number of widths 3 Start  WwWwNwW Stop W(5)wNwNwWwW	Digits and upper case A to F
Databar	Number of widths 8 Start Nn Stop nN	14 Digits or more.
SICI/SISAC	Number of widths 4 Start  W(2)nN Stop W(2)n(3)W(3)nNnW(2)	Any, but using format shown under sample
Telepen	Number of widths 2 Start  NnNnNnNnNnW Stop WwNnNnNnNnN	Any There are alternative start and stop sequences