ZPL Font Inspector

How to use the font inspector

1. Paste the ZPL exactly as your system sends it — including any ~DU or ~DY font downloads at the top, because the inspector matches ^A@ calls against them.
2. Pick the printer resolution if you know it; that turns dot sizes into millimetres. On automatic, the tool infers it only when the label size matches exactly one standard size and says so.
3. Click Inspect. Every text field appears with the font it calls (^A letter, ^A@ downloaded font, or the ^CF default), its type, height × width in dots and mm, rotation and horizontal scaling.
4. Read the notes: missing ^A@ fonts, unknown font letters, bitmap fonts A–H, downloaded fonts nobody uses, fields under 1 mm and ^CI settings the preview cannot honour. Then read the preview note — it tells you what the screen substitutes.

Who this is for

Anyone whose label looks right on screen and wrong on paper. Fonts are the most common reason: Zebra's built-in fonts are proprietary, so every preview tool — this one included — draws them with a stand-in; ^AA and ^A0 look identical in the browser and completely different on a ZD421. A template that calls ^A@ with a font nobody downloaded falls back to the printer default without an error. A ~DU block copied from another template ships 200 KB to the printer on every job for a font no field uses. This inspector puts all of that in one table, straight from the ZPL, and states in plain words what the preview engine substitutes and what it renders exactly (downloaded fonts). It does not judge legibility: a 1 mm character is a number, whether a scanner or a person can read it depends on the printer and the media.

Frequently asked questions

• Why do ^AA and ^A0 look the same in the preview? — Because Zebra's built-in fonts are proprietary and cannot be shipped in a preview engine. Labelixa draws all built-in fonts with one substitute calibrated to the width of font 0. The inspector says this on every result so you do not mistake the screen for the printer.
• What does "Missing (^A@ not downloaded)" mean? — The field calls ^A@ with a font path, but no ~DU or ~DY command in the pasted ZPL downloads that font. A real printer that does not already have it in memory silently falls back to its default font. Either paste the download block too, or use the account font library and let the render prepend it.
• Does the mm column tell me whether the text is readable? — No. It converts dots to millimetres at the chosen resolution, nothing more. Fields under 1 mm are flagged for a test print because that is where legibility usually breaks down, but the threshold is a reminder, not a verdict.
• Why is a downloaded font flagged as unused? — The file downloads it with ~DU or ~DY, but no ^A@ field references its path. It still costs printer memory and transfer time on every job — usually a leftover from a copied template.
• Which findings come from the diagnostics engine? — ZPL5001 (^CI other than 28, no conversion applied), ZPL5002 (^A@ font not downloaded) and ZPL5003 (invalid rotation letter in ^A) are produced by the same rules the Diagnostics Hub uses. The inspector adds no rules of its own; it reads the ZPL and reports the engine's constants.