ZPL Viewer: Preview ZPL Labels

See a ZPL label on screen before it ever reaches a printer: pick a retailer template from UCC Templates and fill in the form, or paste your own ZPL, then preview, copy or download it as ZPL, PNG or PDF.

ZPL is the instruction language that tells a label printer what to print and where. The code is hard to judge by eye — a field can sit two millimetres off and you only find out on the printed label. The ZPL Viewer (Utilities → ZPL Viewer, /utilities/zpl-viewer) draws the label on screen first, using the label size and printer resolution you set, so you can check the layout before anything is printed. It works in two ways: start from a retailer label template stored in UCC Templates and just fill in the values, or paste ZPL code of your own and preview that. The preview is drawn locally in your browser.

Step 1: Pick a retailer template#

1. Open Utilities → ZPL Viewer (/utilities/zpl-viewer). The page starts in “Retailer template” mode — if you land on “Custom ZPL” instead, switch back with the toggle at the top.
2. Open the template drop-down and pick a template. You can type to search; each entry is shown as retailer · template name.
3. After you pick one, the page shows the template’s size, version and label kind next to the drop-down, and the label size boxes below are set from the template automatically.

• The list only contains UCC label templates. The templates themselves are created and edited in WMS → UCC Templates (/wms/templates); the viewer only uses them.
• If the drop-down says “No UCC templates found”, there is no template to pick yet — add one in WMS → UCC Templates (/wms/templates) first, or use Custom ZPL mode below.

Step 2: Fill in the label content#

1. In the “Fill in label content” card, one field appears for every placeholder written in the template (placeholders look like [[THIS]] in the template’s ZPL). The field name tells you what belongs there.
2. Type the value for each field. The ZPL under the template is updated as you type, and the preview on the right redraws itself a moment later.
3. Made a mess of the form? “Reset” above the card clears every field back to empty, so you can start the values over.

• A field you leave empty stays as its placeholder in the ZPL, and the page warns you with an “Unfilled placeholders” list naming each one — fill them all before you treat the label as final.
• Two characters are removed from values automatically: ^ and ~. They are control characters in ZPL, so a value containing them would break the label — leave them out of names and addresses here.

Or: paste your own ZPL (Custom ZPL mode)#

1. Switch the toggle at the top of Utilities → ZPL Viewer (/utilities/zpl-viewer) to “Custom ZPL”.
2. Paste your ZPL into the “ZPL code” box, or edit what is there — a short example (a simple “Hello ZPL” label) is pre-filled so you can see the shape of the code right away.
3. The preview on the right follows your edits, the same as in template mode.

Step 3: Set the label size and resolution, then check the preview#

1. Set the label width and height in inches. A template sets these from its own stored size (4 × 6 inches if a template has no size); in Custom ZPL mode they start at 4 × 6 — change them to match the labels you actually print on.
2. Pick the resolution that matches your printer: 203 dpi (8 dots/mm, the common thermal setting) or 300 dpi (12 dots/mm, sharper). Text and barcodes are drawn at that sharpness in the preview.
3. The preview redraws by itself shortly after any change. If it ever looks stale, click “Render” to draw it again on the spot.

• If the label code uses a command this viewer does not support, that command is skipped and listed under “Unsupported commands (skipped)” below the preview. The rest of the label still draws — but check the list before trusting the preview.
• If the preview fails completely, an error asks you to check the ZPL code — a missing start or end marker in the code is the usual cause.

Step 4: Copy or download the label#

1. Click “Copy ZPL” to copy the final ZPL code (with your filled-in values in place) to the clipboard, ready to paste wherever you work with it.
2. Or download the label in the format you need: the ZPL button downloads the code as a .zpl file, PNG downloads the preview as a picture, and PDF downloads it as a document whose page is exactly the label size you set.

Docklify features used in this article#

• ZPL Viewer — Utilities → ZPL Viewer (/utilities/zpl-viewer)
• Retailer label templates with fill-in placeholder forms — Utilities → ZPL Viewer → Retailer template mode (/utilities/zpl-viewer)
• UCC Templates (where the label templates are created and edited) — WMS → UCC Templates (/wms/templates)
• Label preview at the real size and resolution (203 / 300 dpi), with copy and download as ZPL / PNG / PDF — Utilities → ZPL Viewer → Print preview (/utilities/zpl-viewer)