Encoding Content.
Printer Encoding Types:
Below are the some sample encoding format that used mostly.
| S No | Encode Format | Supported Languages |
| 1 | UTF-8 | Most of all modern languages which is default option in application |
| 2 | cp1252 cp850 cp1253 cp1252 | French, Spanish, Italian, Portuguese, German Epson TM-T20 |
For Detailed information :
https://docs.oracle.com/javase/8/docs/technotes/guides/intl/encoding.doc.html
Why Encoding Matters for Thermal Printing
Thermal printers don't render text the way a phone screen does — they interpret raw bytes according to a specific character encoding built into the printer's firmware. If the app sends UTF-8 bytes but the printer expects a legacy single-byte encoding (or vice versa), the result is mojibake: garbled symbols, missing accents, or blank boxes where characters should be. This is the single most common cause of "why does my receipt print gibberish" support requests.
Common Encodings and When to Use Them
- UTF-8: the modern default, correct for most recent ESC/POS printers and for English-language content.
- Windows-1252 / ISO-8859-1: common on older European printers for accented Latin characters (é, ñ, ü, etc.).
- GB18030 / GBK: required for Simplified Chinese text on many budget thermal printers sold with Chinese firmware.
- Shift-JIS: used by printers with Japanese-market firmware.
- PC437 / PC850: legacy DOS-era code pages still used by some older receipt printer models for basic symbols and box-drawing characters.
If you're unsure which one your printer expects, check the printer's user manual for its supported code pages, or test each option in Simple Bluetooth Printer's encoding setting and compare the printed output.
Fixing Garbled Output in Simple Bluetooth Printer
Open the app, go to Settings → Encoding, and switch to the code page that matches your printer and language. If you're printing in a non-Latin script and encoding changes don't resolve it, enable Strict Mode instead — it renders the printed output as an image matching the on-screen preview exactly, bypassing the printer's font/encoding limitations entirely.
Related Resources
For the full list of supported connectivity and printing features, see the Simple Bluetooth Printer app page. Developers integrating printing programmatically should also see the Print Intent API guide.