Visual viewer for thermal printer .prn files with ESC/POS formatting — renders receipts beautifully in VS Code.
Version: 1.20.0
Features
Auto-open Visual Viewer
Opens .prn files directly in the visual viewer — no manual command needed.
ESC/POS Rendering
- Bold, double-height, double-width text
- Inverted blocks (white text on dark background)
- Centered and right-aligned text
- Separator lines
QR Code Rendering
Automatically detects and renders QR codes embedded in the .prn file.
Multi-format Support
- Binary ESC/POS (raw bytes from thermal printers)
- Text log format (
<@BoldOn>,<@CenterAlign>, etc.)
Dark / Light Mode
Toggle between dark mode (default) and light mode (white paper look) with the toolbar button.
Font Size Controls
Use A+ / A− buttons to fine-tune the font size without reloading.
Live Reload
The viewer automatically updates when the .prn file changes on disk.
Toggle to Raw Text
Use the <> button in the editor title bar to switch to plain text and back.
Usage
- Open any
.prnfile — the visual viewer opens automatically - Use the toolbar buttons (top-right corner of the viewer):
A−/A+— decrease / increase font size- 🌙 / ☀️ — toggle dark / light mode
- To view raw bytes: click the
<>icon in the editor title bar
Commands
| Command | Description |
|---|---|
PRN: Open Visual Viewer |
Open the visual viewer for the active .prn file |
PRN: Open as Text |
Switch to the plain text editor |
Access via Ctrl+Shift+P → PRN: ...
Supported Formats
| Format | Description |
|---|---|
| Binary ESC/POS | Raw .prn bytes directly from a thermal printer |
| Text log | Tags like <@BoldOn>text<@BoldOff>, <@CenterAlign> |
Manual Installation
- Download the
.vsixfile - In VS Code:
Ctrl+Shift+P→ Extensions: Install from VSIX... - Select the
.vsixfile - Reload VS Code
License
MIT