Sum of products: {sum}. Round up to the next
multiple of 10: {next}. Check digit:{' '}
{next} − {sum} = {check}
{check === given ? `, which matches the last digit of ${value}.` : `, but ${value} ends in ${given}: this number is not valid.`}
;
};
const EAN_L = ['0001101', '0011001', '0010011', '0111101', '0100011', '0110001', '0101111', '0111011', '0110111', '0001011'];
const EAN_R = EAN_L.map(p => p.replace(/./g, c => c === '0' ? '1' : '0'));
const EAN_G = EAN_R.map(p => p.split('').reverse().join(''));
const EAN_PARITY = ['LLLLLL', 'LLGLGG', 'LLGGLG', 'LLGGGL', 'LGLLGG', 'LGGLLG', 'LGGGLL', 'LGLGLG', 'LGLGGL', 'LGGLGL'];
const leftChar = k => 3 + 7 * k + 3.5;
const rightChar = (k, halfWidth) => 3 + halfWidth + 5 + 7 * k + 3.5;
const ANATOMY = {
'ean-13': {
length: 13,
quiet: [11, 7],
encode: d => {
const parity = EAN_PARITY[d[0]];
const left = d.slice(1, 7).map((n, i) => (parity[i] === 'L' ? EAN_L : EAN_G)[n]).join('');
const right = d.slice(7).map(n => EAN_R[n]).join('');
return '101' + left + '01010' + right + '101';
},
hri: i => i === 0 ? -6 : i <= 6 ? leftChar(i - 1) : rightChar(i - 7, 42),
number: [[0, 3, 'GS1 prefix', 'Which national GS1 office issued the company prefix. Not the country the product was made in.'], [3, 12, 'Company prefix and item reference', 'The brand owner’s GS1 company prefix followed by its number for this item. Where one ends and the other begins depends on the prefix length, which you can’t tell from the digits alone.'], [12, 13, 'Check digit', 'Calculated from the other 12 digits with GS1 mod-10.']],
leftNote: 'Six digits, each seven modules wide. Each digit is drawn in one of two patterns, and the combination of patterns encodes the first digit, which has no bars of its own.'
},
'upc-a': {
length: 12,
quiet: [9, 9],
encode: d => '101' + d.slice(0, 6).map(n => EAN_L[n]).join('') + '01010' + d.slice(6).map(n => EAN_R[n]).join('') + '101',
hri: i => i === 0 ? -5 : i <= 5 ? leftChar(i) : i <= 10 ? rightChar(i - 6, 42) : 95 + 5,
extended: [[3, 10], [85, 92]],
number: [[0, 11, 'Company prefix and item reference', 'The brand owner’s GS1 company prefix followed by its number for this item.'], [11, 12, 'Check digit', 'Calculated from the other 11 digits with GS1 mod-10.']],
leftNote: 'Six digits, each seven modules wide.'
},
'ean-8': {
length: 8,
quiet: [7, 7],
encode: d => '101' + d.slice(0, 4).map(n => EAN_L[n]).join('') + '01010' + d.slice(4).map(n => EAN_R[n]).join('') + '101',
hri: i => i <= 3 ? leftChar(i) : rightChar(i - 4, 28),
number: [[0, 3, 'GS1-8 prefix', 'Which national GS1 office issued the number.'], [3, 7, 'Item reference', 'Assigned by that GS1 office for this item.'], [7, 8, 'Check digit', 'Calculated from the other 7 digits with GS1 mod-10.']],
leftNote: 'Four digits, each seven modules wide.'
},
'upc-e': {
length: 8,
quiet: [9, 7],
encode: d => {
const forZero = ['GGGLLL', 'GGLGLL', 'GGLLGL', 'GGLLLG', 'GLGGLL', 'GLLGGL', 'GLLLGG', 'GLGLGL', 'GLGLLG', 'GLLGLG'][d[7]];
const parity = d[0] === 0 ? forZero : forZero.replace(/./g, c => c === 'G' ? 'L' : 'G');
return '101' + d.slice(1, 7).map((n, i) => (parity[i] === 'L' ? EAN_L : EAN_G)[n]).join('') + '010101';
},
hri: i => i === 0 ? -5 : i <= 6 ? leftChar(i - 1) : 51 + 4,
guards: () => [[0, 3], [45, 51]],
structure: () => [['Start guard', 0, 3, 'Three modules (bar, space, bar) that tell the scanner where the symbol starts and how wide one module is.'], ['Six digits', 3, 45, 'Each digit is seven modules wide and drawn in one of two patterns. The combination of patterns encodes the number system and the check digit, which have no bars of their own.'], ['End guard', 45, 51, 'Six modules that mark the end of the symbol.']],
number: [[0, 1, 'Number system', 'Always 0 or 1.'], [1, 7, 'Zero-suppressed digits', 'The company prefix and item reference with their zeros removed. The last of the six says where the zeros go back.'], [7, 8, 'Check digit', 'The check digit of the full 12-digit UPC-A.']]
}
};
ANATOMY.isbn = {
...ANATOMY['ean-13'],
number: [[0, 3, 'Prefix', '978 or 979, which mark the number as a book.'], [3, 12, 'Registration group, registrant and publication', 'The language area or country, the publisher, and the edition. Each part varies in length, which is what the hyphens in a printed ISBN show.'], [12, 13, 'Check digit', 'Calculated from the other 12 digits with GS1 mod-10.']]
};
ANATOMY.issn = {
...ANATOMY['ean-13'],
number: [[0, 3, 'Prefix', '977, which marks the number as a serial publication.'], [3, 10, 'ISSN', 'The first seven digits of the ISSN. Its own check digit is left out.'], [10, 12, 'Variant', 'Usually 00. Publishers change it for a special issue or a price change.'], [12, 13, 'Check digit', 'Calculated from the other 12 digits with GS1 mod-10.']]
};
const Anatomy = ({type, value, plain}) => {
const spec = ANATOMY[type];
const digits = String(value).split('').map(Number);
if (!spec || digits.length !== spec.length || digits.some(isNaN)) {
return
Can’t draw {type} for “{value}”.
;
}
const modules = spec.encode(digits);
const n = modules.length;
const half = (n - 11) / 2;
const guards = spec.guards ? spec.guards() : [[0, 3], [3 + half, 8 + half], [n - 3, n]];
const tall = [...guards, ...spec.extended || []];
const isTall = m => tall.some(([a, b]) => m >= a && m < b);
const M = 4;
const [qL, qR] = spec.quiet;
const x = m => (qL + m) * M;
const width = (qL + n + qR) * M;
const labelTop = plain ? 0 : 30, barTop = labelTop + 6, barH = 70, guardH = 76, hriY = barTop + guardH + 4, labelBottom = hriY + 6;
const bottomBracket = labelBottom + 8, height = plain ? labelBottom : bottomBracket + 22;
const bars = [];
for (let m = 0; m < n; m++) {
if (modules[m] !== '1') continue;
let end = m;
while (modules[end + 1] === '1') end++;
bars.push();
m = end;
}
const structure = spec.structure ? spec.structure() : [['Start guard', 0, 3, 'Three modules (bar, space, bar) that tell the scanner where the symbol starts and how wide one module is.'], ['Left half', 3, 3 + half, spec.leftNote], ['Center guard', 3 + half, 8 + half, 'Five modules that separate the two halves. Scanners decode each half on its own, then join them.'], ['Right half', 8 + half, n - 3, 'The remaining digits, each seven modules wide, always drawn from the same set of patterns.'], ['End guard', n - 3, n, 'Three modules that mark the end of the symbol.']];
const numberSegs = spec.number.map(([a, b, name, meaning]) => [name, spec.hri(a) - 3.5, spec.hri(b - 1) + 3.5, meaning]);
const legend = [...structure, ...numberSegs];
const bracket = (key, x1, x2, y, up) => {
const t = up ? y - 4 : y + 4;
return ;
};
const marker = (key, label, cx, y) => {label};
const label = <>
{}
{bars}
{digits.map((d, i) => {d})}
;
if (plain) {
return ;
}
return
{legend.map(([name, , , meaning]) =>
{name}. {meaning}
)}
;
};
const C128 = [[2, 1, 2, 2, 2, 2], [2, 2, 2, 1, 2, 2], [2, 2, 2, 2, 2, 1], [1, 2, 1, 2, 2, 3], [1, 2, 1, 3, 2, 2], [1, 3, 1, 2, 2, 2], [1, 2, 2, 2, 1, 3], [1, 2, 2, 3, 1, 2], [1, 3, 2, 2, 1, 2], [2, 2, 1, 2, 1, 3], [2, 2, 1, 3, 1, 2], [2, 3, 1, 2, 1, 2], [1, 1, 2, 2, 3, 2], [1, 2, 2, 1, 3, 2], [1, 2, 2, 2, 3, 1], [1, 1, 3, 2, 2, 2], [1, 2, 3, 1, 2, 2], [1, 2, 3, 2, 2, 1], [2, 2, 3, 2, 1, 1], [2, 2, 1, 1, 3, 2], [2, 2, 1, 2, 3, 1], [2, 1, 3, 2, 1, 2], [2, 2, 3, 1, 1, 2], [3, 1, 2, 1, 3, 1], [3, 1, 1, 2, 2, 2], [3, 2, 1, 1, 2, 2], [3, 2, 1, 2, 2, 1], [3, 1, 2, 2, 1, 2], [3, 2, 2, 1, 1, 2], [3, 2, 2, 2, 1, 1], [2, 1, 2, 1, 2, 3], [2, 1, 2, 3, 2, 1], [2, 3, 2, 1, 2, 1], [1, 1, 1, 3, 2, 3], [1, 3, 1, 1, 2, 3], [1, 3, 1, 3, 2, 1], [1, 1, 2, 3, 1, 3], [1, 3, 2, 1, 1, 3], [1, 3, 2, 3, 1, 1], [2, 1, 1, 3, 1, 3], [2, 3, 1, 1, 1, 3], [2, 3, 1, 3, 1, 1], [1, 1, 2, 1, 3, 3], [1, 1, 2, 3, 3, 1], [1, 3, 2, 1, 3, 1], [1, 1, 3, 1, 2, 3], [1, 1, 3, 3, 2, 1], [1, 3, 3, 1, 2, 1], [3, 1, 3, 1, 2, 1], [2, 1, 1, 3, 3, 1], [2, 3, 1, 1, 3, 1], [2, 1, 3, 1, 1, 3], [2, 1, 3, 3, 1, 1], [2, 1, 3, 1, 3, 1], [3, 1, 1, 1, 2, 3], [3, 1, 1, 3, 2, 1], [3, 3, 1, 1, 2, 1], [3, 1, 2, 1, 1, 3], [3, 1, 2, 3, 1, 1], [3, 3, 2, 1, 1, 1], [3, 1, 4, 1, 1, 1], [2, 2, 1, 4, 1, 1], [4, 3, 1, 1, 1, 1], [1, 1, 1, 2, 2, 4], [1, 1, 1, 4, 2, 2], [1, 2, 1, 1, 2, 4], [1, 2, 1, 4, 2, 1], [1, 4, 1, 1, 2, 2], [1, 4, 1, 2, 2, 1], [1, 1, 2, 2, 1, 4], [1, 1, 2, 4, 1, 2], [1, 2, 2, 1, 1, 4], [1, 2, 2, 4, 1, 1], [1, 4, 2, 1, 1, 2], [1, 4, 2, 2, 1, 1], [2, 4, 1, 2, 1, 1], [2, 2, 1, 1, 1, 4], [4, 1, 3, 1, 1, 1], [2, 4, 1, 1, 1, 2], [1, 3, 4, 1, 1, 1], [1, 1, 1, 2, 4, 2], [1, 2, 1, 1, 4, 2], [1, 2, 1, 2, 4, 1], [1, 1, 4, 2, 1, 2], [1, 2, 4, 1, 1, 2], [1, 2, 4, 2, 1, 1], [4, 1, 1, 2, 1, 2], [4, 2, 1, 1, 1, 2], [4, 2, 1, 2, 1, 1], [2, 1, 2, 1, 4, 1], [2, 1, 4, 1, 2, 1], [4, 1, 2, 1, 2, 1], [1, 1, 1, 1, 4, 3], [1, 1, 1, 3, 4, 1], [1, 3, 1, 1, 4, 1], [1, 1, 4, 1, 1, 3], [1, 1, 4, 3, 1, 1], [4, 1, 1, 1, 1, 3], [4, 1, 1, 3, 1, 1], [1, 1, 3, 1, 4, 1], [1, 1, 4, 1, 3, 1], [3, 1, 1, 1, 4, 1], [4, 1, 1, 1, 3, 1], [2, 1, 1, 4, 1, 2], [2, 1, 1, 2, 1, 4], [2, 1, 1, 2, 3, 2], [2, 3, 3, 1, 1, 1, 2]];
const C39_CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%';
const C39 = [0x034, 0x121, 0x061, 0x160, 0x031, 0x130, 0x070, 0x025, 0x124, 0x064, 0x109, 0x049, 0x148, 0x019, 0x118, 0x058, 0x00d, 0x10c, 0x04c, 0x01c, 0x103, 0x043, 0x142, 0x013, 0x112, 0x052, 0x007, 0x106, 0x046, 0x016, 0x181, 0x0c1, 0x1c0, 0x091, 0x190, 0x0d0, 0x085, 0x184, 0x0c4, 0x0a8, 0x0a2, 0x08a, 0x02a];
const C39_STAR = 0x094;
const I25 = ['NNWWN', 'WNNNW', 'NWNNW', 'WWNNN', 'NNWNW', 'WNWNN', 'NWWNN', 'NNNWW', 'WNNWN', 'NWNWN'];
const C93 = [0x114, 0x148, 0x144, 0x142, 0x128, 0x124, 0x122, 0x150, 0x112, 0x10a, 0x1a8, 0x1a4, 0x1a2, 0x194, 0x192, 0x18a, 0x168, 0x164, 0x162, 0x134, 0x11a, 0x158, 0x14c, 0x146, 0x12c, 0x116, 0x1b4, 0x1b2, 0x1ac, 0x1a6, 0x196, 0x19a, 0x16c, 0x166, 0x136, 0x13a, 0x12e, 0x1d4, 0x1d2, 0x1ca, 0x16e, 0x176, 0x1ae, 0x126, 0x1da, 0x1d6, 0x132, 0x15e];
const code93 = text => {
const values = [...text].map(c => C39_CHARS.indexOf(c));
const weighted = (vs, max) => vs.reduceRight((acc, v, i) => acc + v * ((vs.length - 1 - i) % max + 1), 0) % 47;
const c = weighted(values, 20);
const k = weighted([...values, c], 15);
const modules = [47, ...values, c, k, 47].map(v => C93[v].toString(2).padStart(9, '0')).join('') + '1';
const widths = [];
for (let i = 0; i < modules.length; ) {
let j = i;
while (modules[j] === modules[i]) j++;
widths.push(j - i);
i = j;
}
const n = values.length;
const name = v => C39_CHARS[v] || `value ${v}`;
return {
widths,
hri: text,
segments: [['Start character', 0, 9, 'Marks the start. Scanners don’t send it.'], ['Data', 9, 9 * (n + 1), 'Each character is 9 modules: three bars and three spaces, each 1 to 4 modules wide.'], ['Check character C', 9 * (n + 1), 9 * (n + 2), `Mod-47 over the data, with weights 1 to 20. Here, ${name(c)}.`], ['Check character K', 9 * (n + 2), 9 * (n + 3), `Mod-47 over the data and C, with weights 1 to 15. Here, ${name(k)}.`], ['Stop', 9 * (n + 3), 9 * (n + 4) + 1, 'The stop character, then a single-module bar that ends the symbol.']]
};
};
const code39 = text => {
const chars = [...text];
const check = C39_CHARS[chars.reduce((sum, c) => sum + C39_CHARS.indexOf(c), 0) % 43];
const element = bits => Array.from({
length: 9
}, (_, i) => bits >> 8 - i & 1 ? 3 : 1);
const parts = [C39_STAR, ...chars.map(c => C39[C39_CHARS.indexOf(c)]), C39[C39_CHARS.indexOf(check)], C39_STAR];
const widths = [];
parts.forEach((bits, i) => {
widths.push(...element(bits));
if (i < parts.length - 1) widths.push(1);
});
const char = 16;
const n = parts.length;
return {
widths,
hri: text + check,
segments: [['Start character', 0, 15, 'An asterisk. It marks the start, and scanners don’t send it.'], ['Data', char, char * (n - 2) - 1, 'Each character is nine elements, five bars and four spaces, three of them wide. A narrow gap separates characters.'], ['Check character', char * (n - 2), char * (n - 1) - 1, `Optional. The mod-43 check for this data is ${check}.`], ['Stop character', char * (n - 1), char * n - 1, 'Another asterisk, which marks the end.']]
};
};
const code128Values = (text, gs1) => {
const digitsAt = i => {
let n = 0;
while ((/\d/).test(text[i + n] || '')) n++;
return n;
};
let set = digitsAt(0) >= 4 ? 'C' : 'B';
const values = [set === 'C' ? 105 : 104];
if (gs1) values.push(102);
for (let i = 0; i < text.length; ) {
if (text[i] === '\x1d') {
values.push(102);
i += 1;
continue;
}
if (set === 'C') {
if (digitsAt(i) >= 2) {
values.push(Number(text.slice(i, i + 2)));
i += 2;
} else {
values.push(100);
set = 'B';
}
} else if (digitsAt(i) >= 4 && digitsAt(i) % 2 === 0) {
values.push(99);
set = 'C';
} else {
values.push(text.charCodeAt(i) - 32);
i += 1;
}
}
return values;
};
const code128 = (text, gs1) => {
const data = gs1 ? gs1Text(text) : text;
const values = code128Values(data, gs1);
const check = values.reduce((sum, v, i) => sum + v * (i || 1), 0) % 103;
const widths = [...values, check, 106].flatMap(v => C128[v]);
const head = gs1 ? 22 : 11;
const end = values.length * 11;
const startSet = values[0] === 105 ? 'C' : 'B';
const startNote = startSet === 'C' ? 'The first characters are digits, packed two to a character.' : 'The first characters are text. The start code also counts toward the check.';
return {
widths,
hri: text,
segments: [[`Start code ${startSet}`, 0, 11, startNote], ...gs1 ? [['FNC1', 11, 22, 'A special character that marks the barcode as GS1-128. Scanners don’t send it as data.']] : [], ['Data', head, end, gs1 ? 'Each character is 11 modules: three bars and three spaces. Digits are packed two to a character in code set C, then a switch to code set B handles the letters.' : 'Each character is 11 modules: three bars and three spaces, each 1 to 4 modules wide.'], ['Check character', end, end + 11, `Mod-103 check, value ${check}. Scanners verify it, then drop it.`], ['Stop', end + 11, end + 24, 'Thirteen modules, ending in a final bar.']]
};
};
const itf = (digits, wide = 2.5) => {
const widths = [1, 1, 1, 1];
for (let i = 0; i < digits.length; i += 2) {
const bars = I25[digits[i]], spaces = I25[digits[i + 1]];
for (let k = 0; k < 5; k++) widths.push(bars[k] === 'W' ? wide : 1, spaces[k] === 'W' ? wide : 1);
}
widths.push(wide, 1, 1);
const pair = 2 * (3 + 2 * wide);
const end = 4 + pair * (digits.length / 2);
return {
widths,
hri: digits,
segments: [['Start', 0, 4, 'Four narrow elements: bar, space, bar, space.'], ['Digit pairs', 4, end, 'Each pair of digits shares five bars and five spaces. The first digit sets which bars are wide, the second which spaces are wide.'], ['Stop', end, end + wide + 2, 'A wide bar, a narrow space and a narrow bar.']]
};
};
const GS1_AI_NAMES = {
'00': ['SSCC', 'The serial shipping container code: an 18-digit number for one pallet or parcel.'],
'01': ['GTIN', 'The product’s 14-digit GTIN.'],
10: ['Batch or lot', 'Up to 20 characters. Variable length, so it comes last or is followed by a separator.'],
11: ['Production date', 'YYMMDD.'],
15: ['Best before date', 'YYMMDD.'],
17: ['Expiry date', 'YYMMDD.'],
21: ['Serial number', 'Up to 20 characters.'],
37: ['Count', 'How many trade items the unit contains.']
};
const LINEAR = {
'code-39': {
quiet: 10,
encode: v => code39(v)
},
'code-93': {
quiet: 10,
encode: v => code93(v)
},
'code-128': {
quiet: 10,
encode: v => code128(v, false)
},
'gs1-128': {
quiet: 10,
encode: v => code128(v, true),
numbers: hri => [...hri.matchAll(/\((\d{2,4})\)[^(]*/g)].map(m => {
const [name, meaning] = GS1_AI_NAMES[m[1]] || [`AI ${m[1]}`, ''];
return [m.index, m.index + m[0].length, `(${m[1]}) ${name}`, meaning];
})
},
'interleaved-2-of-5': {
quiet: 10,
encode: v => itf(v)
},
'itf-14': {
quiet: 10,
bearer: true,
encode: v => itf(v),
numbers: () => [[0, 1, 'Indicator digit', 'The packaging level. 1 to 8 mean a case or other grouping of the same item.'], [1, 13, 'Item number', 'Often the first 12 digits of the item’s own GTIN-13, but not always.'], [13, 14, 'Check digit', 'GS1 mod-10, calculated over all 14 digits.']]
}
};
const Linear = ({type, value, plain}) => {
const spec = LINEAR[type];
if (!spec || !value) return
;
};
ZipZapKit hasn't been released yet. The API names on this page are provisional and may change.
Most people know what they're scanning, products, shipping labels, IDs, but not which barcode types those use. Groups let you say the first and get the second: enable a group, and a field reads every barcode type in it.
Groups work like tags, not folders. A barcode type can carry any number of them, and a group isn't simply a subset of a bigger one.
This page lists what's in each group. Whether a particular reader can read each type is a separate question, answered on each barcode type's page.
## How groups work
* **Groups overlap.** A barcode type can be in several groups. GS1-128 is in Logistics and shipping, GS1, and 1D.
* **Enabling two groups gives you both.** The field reads any barcode type in either group.
* **Narrower is better.** Every extra barcode type a field accepts makes camera scanning a little slower and wrong reads a little more likely. Pick the narrowest group that covers what you scan.
```swift theme={null}
ScanField("Product barcode", text: $gtin)
.barcodeTypes(.retailProduct)
```
See [Barcode types](/sdk/modifiers/barcode-types) for combining groups and choosing individual types.
## The groups
### Retail product
For the barcode on the thing a shopper hands you: every barcode that identifies a product by its GTIN.
QR Code and Data Matrix are in this group only when they carry a GTIN, because products are starting to use them at checkout. See [Sunrise 2027](/reference/sunrise-2027). Any other QR code, such as a link on a poster, isn't a product barcode, and a field set to this group ignores it.
#### How ZipZapKit tells whether a 2D barcode carries a GTIN
A QR Code or Data Matrix counts as a product barcode in two cases:
| It contains | How ZipZapKit recognizes it |
| - | - |
| A GS1 Digital Link: a web address with `/01/` followed by a GTIN | From the content: the address is in Digital Link form and the GTIN's check digit is valid. Works the same with every reader. |
| GS1 data, as in GS1 DataMatrix or GS1 QR Code | ZipZap hardware reports the barcode's symbology identifier (`]d2` or `]Q3`), which marks GS1 data. The camera doesn't report it, so ZipZapKit infers it from the content: the data must parse as GS1 data starting with a GTIN whose check digit is valid. |
The camera's inference is rarely wrong, because ordinary text almost never parses as GS1 data with a valid check digit.
### Logistics and shipping
For cases, pallets and parcels: the barcodes on the outside of a box rather than the product inside.
### GS1
For barcodes that can carry GS1 data beyond a product number: Application Identifiers such as batch numbers and expiry dates, or a GS1 Digital Link. Use it with ZipZapKit's GS1 parsing. See [GS1 Application Identifiers](/sdk/gs1/application-identifiers).
### 1D (linear)
Every linear barcode type. This group is defined by shape rather than purpose, so it's rarely the right choice: a field that accepts every 1D barcode will happily read the wrong one. Prefer a group that matches what you're scanning.
### 2D (matrix)
Every 2D barcode type. Like 1D, it's broad. It suits fields that scan codes you generate yourself, where you control the barcode type.
### Postal
The barcodes postal services print on mail for sorting and tracking.
### ID and documents
Barcodes and printed text on identity documents: the PDF417 barcode on North American driver's licenses, and the MRZ on passports and ID cards. The MRZ is printed text, not a barcode, and needs a reader with text recognition. See [AAMVA test barcodes](/hardware/aamva-test-barcodes) for test data.
## Every barcode type and its groups
This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.