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Utilities · Local utility

Barcode Generator

Generate CODE128, EAN-13, or UPC-A barcodes; EAN/UPC check digits are computed or verified. Export PNG or SVG, with optional human-readable value below the bars.

Task path / input to outcome

Pick the symbology

Runs locally · Nothing is uploaded

How Barcode Generator works, privacy, and related tools

Task path / input to outcome

How to generate a barcode

  1. 01

    Pick the symbology

    Choose CODE128, EAN-13, or UPC-A under Format. Switching the format fills in a valid example value for it — a CODE128 code, a 12-digit EAN-13 base, or an 11-digit UPC-A base — so you always start from data that scans, and you can see the expected shape of the data before typing your own.

  2. 02

    Enter the value

    Type the data into Value, up to 64 characters. CODE128 accepts 1–64 printable ASCII characters, letters, digits, and symbols included. For EAN-13 enter the 12 data digits, for UPC-A the 11 — the checksum digit is calculated automatically, and if you paste the full 13- or 12-digit value including a checksum, that digit is verified and a mismatch names the expected number.

  3. 03

    Style the barcode

    Outer margins grow with bar width: at least 12 narrow modules on each side. Keep the full margin when placing the image. Use dark marks on a light background. The 3:1 contrast check is only an initial filter, not a scan guarantee. This is a size estimate, not embedded DPI metadata or print certification. Keep integer scaling, preserve quiet zones and test the final output with the intended scanner.

  4. 04

    Generate and export

    Press Generate barcode; the renderer loads into this tab on demand. The validated PNG preview and SVG encode the normalized value, including a computed EAN-13 or UPC-A check digit. The human-readable value appears beneath the bars only when Display value is enabled; the bars still encode the same value when the text is hidden. Download toolars-barcode.png or toolars-barcode.svg, or use Copy SVG for the vector markup.

Tool facts

Processing
In your browser
Input leaves this device
Never
Retention
Nothing is stored
Price
Free

Your input stays in the browser.

Barcode Generator uses its verified local execution path and does not create a hidden input or output history.

Local execution

Runs inside the current browser tab.

No hidden processing

Active tool data never becomes a Toolars document record.

No account required

Use the core workflow without creating a profile. Favorites sync to your account after you sign in.

Immediate reset

Clear the tab and the active working data is gone.

What Barcode Generator actually does

A bakery prints shelf labels for its forty products and needs the same EAN-13 on the sign that the wholesaler invoiced; a warehouse team tapes CODE128 codes onto storage bins and wants the human-readable line printed beneath; a developer checks whether a scanning app validates EAN-13 checksums correctly and feeds it deliberately wrong digits. Barcode Generator validates the data before a single bar is drawn — and because everything renders inside the tab, unreleased product codes and internal SKUs never travel to a generator service.

Common questions

Which formats are supported, and what data do they take?
Three retail and logistics symbologies. CODE128 holds 1–64 printable ASCII characters — letters, digits, and symbols — which suits internal SKUs, shelf bins, and inventory tags. EAN-13 takes exactly 12 data digits and UPC-A exactly 11, with the final checksum digit calculated automatically; both also accept the full length including a checksum, which is then verified rather than recomputed silently. If your data comes from a GS1 assignment, paste the digits as issued and let the tool do the arithmetic.
Why does it say my checksum is invalid?
If you enter the full 13-digit EAN-13 or 12-digit UPC-A value including the checksum, that last digit is verified against the standard weighted calculation, and the error names the expected digit. This usually means the source value had a typo. Enter only the data digits — 12 or 11 — and the correct checksum is computed for you.
What are the size and color limits?
Outer margins grow with bar width: at least 12 narrow modules on each side. Keep the full margin when placing the image. One-pixel bars leave little room for resizing or print errors. Increase bar width and test at the final physical size. Use dark marks on a light background. The 3:1 contrast check is only an initial filter, not a scan guarantee. This is a size estimate, not embedded DPI metadata or print certification. Keep integer scaling, preserve quiet zones and test the final output with the intended scanner.
Is my data uploaded anywhere?
No. The barcode renderer loads into this tab and runs locally; the values you enter never leave your device, no account is required, and resetting the workspace discards everything. Downloads produce the PNG and SVG files only when you choose them.

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