Bulk Interleaved 2 of 5 barcode generator

Interleaved 2 of 5 pairs its digits — two of them share every pattern — so the one rule that governs a batch is arithmetic rather than editorial: every value must have an even number of digits. A list where half the rows are seven digits long is a list where half the rows will be padded, and padding changes the number.

One value per line. A single line of comma- or semicolon-separated values works too. A header row (like “Value”) counts as a value and will be rejected — leave it out.

Nothing recognized yet.

Appearance
Size
Caption
Caption position
Caption alignment
Colours

Enter a value — the code appears here.

Specification

Character set
digits
Length
from 2 to 30 characters
Check digit
not used by this symbology

Need the specification and use cases first? What is Interleaved 2 of 5?

Where this code earns its place in a batch

  • Purely numeric carton runs where width is the constraint: pairing two digits into one pattern makes it the most compact linear symbology for digits alone.
  • Distribution packaging read by fixed scanners rather than handhelds — the symbol tolerates coarse printing on board, which is where its numeric density pays off.
  • Batches that never leave your own equipment: without a check digit it is a poor choice for anything a partner scans, and a reasonable one inside a closed loop.

Preparing the list

  • Normalise the digit count across the batch before generating: pad to an even length deliberately, with a leading zero you chose, rather than letting something else choose it.
  • Use a fixed-width sequence when the values are a counter — it keeps the parity constant for the whole run without a second thought.
  • Add bearer bars for anything printed on corrugated: without the frame, a partial scan across the top or bottom of the symbol can return a short, valid-looking number.

What goes wrong in a batch

  • Odd-length values. The batch will not simply refuse them; whatever pads them decides the leading digit, and a leading digit is part of the number.
  • Relying on the symbol's own boundaries. Interleaved 2 of 5 has no check digit by default and no unique stop pattern in the middle, which is what makes short reads possible.

Frequently asked questions

Why must every value have an even number of digits?
Because the format interleaves pairs: the first digit is encoded in the bars, the second in the spaces between them. An odd count leaves one digit without a partner, so a zero has to be added somewhere — and that zero becomes part of the value.
Should the batch carry a check digit?
It is optional in bare Interleaved 2 of 5 and mandatory in ITF-14. Given that the main failure mode is a short read producing a plausible number, adding one is worth the extra digit on anything that leaves your own equipment.