To get your HP printer back online, follow these key steps:

1. **Check Printer Connection**
– Ensure the printer is properly connected to your computer by USB cable or to your Wi-Fi network if wireless.
– Confirm cables are secure and the printer is connected to the same Wi-Fi network as your computer[1][3].

2. **Restart Devices**
– Turn off and unplug the printer.
– Restart your computer and router.
– Power on the printer again and check if it comes online[1].

3. **Set Printer as Default and Disable Offline Mode**
– On Windows, open Control Panel > Devices and Printers (or Settings > Devices > Printers & Scanners).
– Right-click your HP printer and click “Set as Default Printer.”
– Also right-click the printer, go to “See what’s printing,” open the Printer menu, and *uncheck* “Use Printer Offline” to bring it online[1][3][4].

4. **Clear Print Queue**
– Cancel any stuck print jobs from the print queue window to prevent blocking new jobs[1].

5. **Run HP Print and Scan Doctor or HP Smart Diagnostic Tools**
– Download and run the **HP Print and Scan Doctor** tool from HP’s website for automatic troubleshooting.
– Alternatively, use the Diagnose & Fix option in the HP Smart desktop app[2].

6. **Update Printer Drivers and Firmware**
– Download the latest drivers from HP.com tailored for your printer model to avoid driver-related offline issues[2][4].

If these steps do not resolve the problem, consult the printer manual or HP support for model-specific assistance[1][2].

In summary, ensuring proper connection, disabling “Use Printer Offline,” setting it as default, clearing print jobs, running HP diagnostic tools, and updating drivers are the most effective ways to get your HP printer back online.