B21 Pro official software list
In the official Windows model list, choose B21Series and confirm B21_Pro. The manufacturer calls this NIIMBOT PC software Driver-Free; mobile label apps and third-party-software drivers have different roles.
Identify the exact B21 Pro
B21 Pro is a 300 dpi thermal label printer; the manual names it B21_Pro and specifies a 48 mm print width. B21, B21S and B21-C2B are separate listed identities. Do not transfer their manuals or connection limits to this Pro guide.
Apps, PC software and driver roles
| Item | Check |
|---|---|
| Windows PC | NIIMBOT Windows Version (Driver-Free) 4.2.6 currently lists B21_Pro under B21Series. CPU architecture and supported Windows releases were not established from that row. |
| NIIMBOT mobile app | The exact manual recommends NIIMBOT for commercial label editing and batch workflows; use the official App Store / Google Play route. |
| NIIM mobile app | The manual separately recommends NIIM for household labels and creative templates. App naming does not establish a particular current phone-OS release. |
| Other components | Third-party-software drivers and firmware are separate from the NIIMBOT editing app. Do not replace a working component solely because another package name appears. |
This guide does not establish a current Mac, Linux or ARM installation route. A listed download is not an installed-operation test. Keep the full Pro model identity when checking later compatibility.
USB data and phone Bluetooth
| Item | Check |
|---|---|
| Computer / Type-C | The manual requires the supplied cable or another data-capable cable for computer use. A charging-only lead is not proof of a data connection. |
| Phone / Bluetooth | Turn on phone Bluetooth, search inside the app and select the printer, then open Drawing Board. Android may require location permission. If a PIN is requested, the manual gives 0000 or 1234. |
| Other networks | The exact manual lists Bluetooth and Type-C. No Wi-Fi or Ethernet printing route is verified here. |
Load labels with the printing face down
Open the cover using its release lever and keep clear of the sharp blade. Move the roll holders outward, place the roll with the printing surface facing down, secure it with the holders and pull the first label through the outlet before closing the cover. Match the stock and template size/type.
Power button: feed and on/off
The Basic operations table gives a three-second power-button hold to turn on or off. Its installation page says 2–3 seconds for startup. One press while on feeds paper; two presses print the test page. These are different actions, not a FEED button on this model.
Double-press device self-test
With the device on and paper loaded, quickly press the power button twice. Compare the device-only test with the app job. If only host jobs fail, compare this B21 Pro software and selected connection; persistent abnormal self-tests need support.
B21 Pro label-printing checks
Six indicator conditions
| Item | Check |
|---|---|
| Blue, flashing | Firmware upgrading. |
| Blue, steady | Standby. |
| Green, flashing | Printing. |
| Green, steady | Bluetooth connected. |
| Red, flashing | Charging; when powered off, the light goes out once charged. |
| Red, steady | Cover open, paper out or paper-output error. |
Eight symptom checks
| Item | Check |
|---|---|
| Blank output | Compare roll direction and the self-test. Check → |
| Continuous feed / red flash | Use the separate feed-calibration check. Check → |
| Offset / extra labels | Compare template size, orientation and media type. Check → |
| Lid-open prompt | Check complete cover closure. Check → |
| Bluetooth absent | Check phone Bluetooth and actual app model. Check → |
| PC cannot connect | Compare a data-capable USB lead and software. Check → |
| Supply not recognised | Check the correct RFID stock and its self-test information. Check → |
| No power | Check compliant charging equipment and the manual note. Check → |
Continuous feed, position and RFID recognition
For continuous feeding with a flashing red light, the exact FAQ gives NIIMBOT app → My → My Hardware → Paper Feed Calibration, with the correct paper type. This combined symptom differs from the manual’s ordinary charging indication. For recognition errors, the FAQ also checks RFID supplies: P≥L indicates a count limit; missing R or ERR needs supply/device support.
Charging, power and care
The manual specifies 5 V DC, 1 A input and a compliant adapter. If it will not turn on, its final note says charge for one hour before retrying. Avoid corrosive cleaners and do not disassemble the device or replace its battery yourself. Contact support for persistent faults; no head-cleaning solvent or factory reset is prescribed here.
Official sources and verification scope
Verified 21 October 2026: exact manufacturer B21 Pro support/resource mapping, linked English manual (13 PDF pages), selected complete pages, official store product and current Windows list. Manual download filename says V1.1; the document carries 2024 copyright. No installer, firmware or physical printing was run.