What Channel Code is
Channel Code is a real, distinct linear symbology with its own encoder -- confirmed directly: bwipp_channelcode draws its bars via bwipp_renlinear() itself using its own combinatorial-encoding functions, not another symbology's tables.
Generate it now
Enter a 2-to-7-digit number to see a live preview.
Valid input
The value must be 2 to 7 digits ("Channel Code must be 2 to 7 digits") and digits only ("Channel Code must contain only digits"). Each digit count has its own real maximum encodable value (the number of usable "channels" for that length): 26 for 2 digits, 292 for 3, 3493 for 4, 44072 for 5, 576688 for 6, and 7742862 for 7 -- a value exceeding the maximum for its own digit count is rejected ("The Channel Code value is too big for the number of channels").
Key options
Supported options include shortfinder (a 5-bar finder pattern instead of the default 9-bar pattern), includetext, includecheck (adds a computed Modulo-23 check character), and height. bwip-js's own real, literal default for height is the plain number 1 -- unlike every other height option in this catalog (which use an internal auto-compute sentinel), this default bypasses bwip-js's own millimetre-to-inch conversion entirely and is used directly as 1 inch (25.4mm); an explicit height value you supply IS still interpreted in millimetres as usual.
Output and printing
Export SVG for vector-precise label artwork or PNG for a quick proof.
Common uses
Channel Code suits compact numeric identification where a small linear symbol encoding a bounded numeric range is needed.
Example
See the live preview above, seeded with a bwip-js-verified valid value.
Size guidance
Leaving height unset renders at bwip-js's own real default of 1 inch (25.4mm); this is NOT the same as explicitly entering "1" into a millimetre-based height field (which renders a drastically shorter symbol) -- an explicit height value is always interpreted in millimetres.
Troubleshooting
A rejected value is usually the wrong digit count (2 to 7 only), a non-digit character, or a value too big for its own digit count's maximum channel value.
Related formats
Related formats: Code 128 and Code 39 (other general-purpose linear symbologies already in this catalog) -- each is a separately implemented encoder, not a variant of Channel Code.
FAQ
Why does my height:1 setting render such a short symbol?
Channel Code's real default height (when the option is left out entirely) is 1 inch (25.4mm) -- but any height value you DO supply is always interpreted in millimetres. Entering "1" therefore means 1 millimetre, not 1 inch, producing a drastically shorter symbol. Leave the field blank to get the real 25.4mm default, or enter 25.4 explicitly for the same result.
What is the maximum value I can encode?
It depends on how many digits you enter: 26 for 2 digits, up to 7742862 for 7 digits. Each digit count has its own real maximum; a value exceeding it for that digit count is rejected even if it would be a valid value at a different digit count.